Free-cutting brass C36000 C360
CuZn36Pb3, UNS C36000: copper 60.0 to 63.0 wt%, lead 2.5 to 3.0 wt%, iron 0.35 wt% maximum, zinc remainder
Also known as UNS C36000, EN name CW603N, EN name CuZn36Pb3, CDA C360, ASTM B16, Free Machining Brass · 2 more
Free-cutting brass C36000 (UNS C36000, CuZn36Pb3) is a copper-zinc alloy with 2.5 to 3.0 % lead, made for high-speed screw-machine work.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Cut fast
machinability rated 100
Carry current
26 %IACS
Carry heat
116 W/(m·K)
Strength by temper
330 to 480 MPa minimum tensile
Weight
8.5 g/cm3
Recipe, share of the weight
- Cu not statedCopper
- Zn not statedZinc
- Pb not statedLead
- Fe not statedIron
Best for
High-volume machined parts such as screw-machine products, fasteners and valve components, where machinability rated 100 matters most
Weakest at
Corrosion in water (dezincification, about 35 % zinc) and in ammonia (season cracking), plus its 2.5 to 3.0 % lead content
Risk at a glance
- People Moderate. Leaded alloy
- If it fails Moderate. Dezincification of brass in water
- Corrosion Moderate. Brass with more than 15 % zinc dezincifies: zinc leaves the alloy and a weak copper layer is left.
Quick facts: C360
| Property | Value | Basis |
|---|---|---|
| Density | 8.5 g/cm³ | 1 sourced value |
| Yield strength | at least 130 MPa | 4 sourced values across conditions |
| Tensile strength | at least 330 MPa | 4 sourced values across conditions |
| Thermal conductivity | 116 W/(m·K) | 1 sourced value |
| Thermal expansion (CTE) | 20.5 ppm/K | 1 sourced value |
| Melting point | 954 to 1,049 °C | 2 sourced values across conditions |
| Electrical resistivity | 6.6e-8 Ω·m | 1 sourced value |
What is the density of Free-cutting brass C36000?
Free-cutting brass C36000 has a density of 8.5 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Free-cutting brass C36000?
Free-cutting brass C36000 has a thermal conductivity of 116 W/(m·K). The source and test conditions are listed in the properties table on this page.
What is the coefficient of thermal expansion of Free-cutting brass C36000?
Free-cutting brass C36000 has a coefficient of thermal expansion of 20.5 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Free-cutting brass C36000?
Free-cutting brass C36000 has a melting point of 954 to 1,049 °C. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the yield strength of Free-cutting brass C36000?
Free-cutting brass C36000 has a yield strength of at least 130 MPa. The range covers 4 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What are the other names and codes for Free-cutting brass C36000?
Free-cutting brass C36000 is also written as UNS C36000, EN name CW603N, EN name CuZn36Pb3, CDA C360, ASTM B16, Free Machining Brass. Each code is printed in the source listed beside it in the designations table.
What is Free-cutting brass C36000 used for?
Uses recorded in the sources include Automatic screw-machine products and fasteners; Plumbing components, fittings, adaptors and fluid connectors (terrestrial use).
Why it exists
Free-cutting brass is chosen for ease of machining. National Bronze says its two-phase structure forms broken chips instead of long coils, and that the lead content adds internal lubrication against the cutting tool. The alloy is rated 100 on the supplier machinability scale. It conducts electricity at 26 %IACS and heat at 116 W/(m·K) at 20 °C (Fisk MA36B). Its density is 8.5 g/cm3. The lead content is the reason it falls outside California's lead-free plumbing rule, and it is the main health concern in these sources.
Where it's used
Screw-machine parts and fasteners
National Bronze lists screw machine products, valve components, fasteners, fittings, hardware, fluid connectors and automotive sensor housings as C36000 applications. Smith lists machine screw parts, high-volume parts, plumbing components and fluid connectors.
Fittings and fluid connectors
Smith says C36000 offers good corrosion resistance and is readily brazed or soldered, and lists fittings and adaptors and fluid connectors among its applications. These are terrestrial uses; no source names a space system.
Recipe
CuZn36Pb3, UNS C36000: copper 60.0 to 63.0 wt%, lead 2.5 to 3.0 wt%, iron 0.35 wt% maximum, zinc remainder
Free-cutting brass is a copper-zinc alloy with 2.5 to 3.0 % lead. National Bronze says its two-phase structure forms broken chips. Wikipedia says lead is often added at about 2 % to improve machinability, and that it forms globules at the grain boundaries as the casting cools.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Copper Cu | not stated | Main metal and matrix of the alloy (limits from Aviva, Fisk and Smith). |
| Zinc Zn | not stated | The alloying element that makes the brass. Above 15 % zinc, dezincification risk rises (Aviva). |
| Lead Pb | not stated | Added for machinability; National Bronze says the lead content adds internal lubrication against the cutting tool. |
| Iron Fe | not stated | Impurity limit printed on the Aviva, Fisk and National Bronze pages. |
Weight shares are as printed in the sources.
What it can do
Cut fast
machinability rated 100
Aviva and National Bronze give C36000 a machinability rating of 100, and National Bronze calls it the standard against which other metals are measured. The scale is the supplier's, not a measured value.
Carry current
26 %IACS
Electrical conductivity is 26 %IACS when annealed (Fisk) and 26 % in the half-hard H02 bar (Aviva). Fisk prints an electrical resistivity of 6.63 µΩ·cm at 20 °C when annealed.
Carry heat
116 W/(m·K)
measured
Thermal conductivity is 116 W/(m·K) at 20 °C (Fisk MA36B, metric column).
Strength by temper
330 to 480 MPa minimum tensile
Round rod minimum tensile strength is 330 MPa annealed, 390 MPa half hard and 480 MPa hard (Fisk). Aviva gives 395 MPa minimum for half-hard bar 12.7 mm and under.
Weight
8.5 g/cm3
measured
Density is 8.5 g/cm3 (Fisk MA36B, metric column).
Melting
954 to 1049 °C
The solidus is 954 °C and the liquidus is 1049 °C (Fisk MA36B, metric column).
Expansion
20.5 ppm/K
measured
The coefficient of thermal expansion is 20.5 ppm/K over 20 to 300 °C (Fisk MA36B, printed as per °C).
How it compares
The [copper profile](/profiles/copper/) covers the pure metal, and it is the natural comparison for conductivity and density. Within the Aviva comparison, its lead-free Model 3 alloy has a higher minimum yield strength and a higher electrical conductivity than C36000 half-hard bar 12.7 mm and under (170 MPa and 26 %IACS for C36000). It has a lower minimum tensile strength and a lower machinability rating (395 MPa and 100 for C36000). These are Aviva's own figures for its own alloy, so they are a vendor's comparison and not an independent test.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | C360 | Cu | C954 | C630 | BeCu | C510 | C260 | Cu-Ag | CuCrZr | CuNi 70/30 | C21000 | CW614N | C75200 | C521 | C655 | Cu-Te | Sn/Cu |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | |||||||||||||||||
| Solidus, C36000 (Fisk MA36B) | 954 °C2 | 1083 °C | 1027 °C | 1060 °C | 870 °C | 954 to 1049 °C | 916 °C | no data | 1081 °C | 1170 to 1240 °C | 954 °C | 875 to 890 °C | 1060 to 1110 °C | 882 to 1027 °C | 971 to 1027 °C | 1080 °C | 231.9 °C |
| Liquidus, C36000 (Fisk MA36B) | 1049 °C3 | 1083 °C | 1027 °C | 1060 °C | 870 °C | 954 to 1049 °C | 916 °C | no data | 1081 °C | 1170 to 1240 °C | 954 °C | 875 to 890 °C | 1060 to 1110 °C | 882 to 1027 °C | 971 to 1027 °C | 1080 °C | 231.9 °C |
| Thermal conductivity at 20 °C, C36000 (Fisk MA36B) | 116 W/(m·K)4 | 391 W/(m·K) | 58.7 W/(m·K) | 63 W/(m·K) | 105 W/(m·K) | 84 W/(m·K) | 121.2 W/(m·K) | no data | 323 W/(m·K) | 29 W/(m·K) | 234 W/(m·K) | 123 W/(m·K) | 32 W/(m·K) | 67 W/(m·K) | 36.3 W/(m.K) | 355 W/(m·K) | 66.6 W/(m·K) |
| Physical and electrical | |||||||||||||||||
| Density, C36000 (Fisk MA36B) | 8.5 g/cm³1 | 8.9 g/cm³ | 7.45 g/cm³ | 7.58 g/cm³ | 8.36 g/cm³ | 8.86 g/cm³ | 8.53 g/cm³ | no data | 8.94 g/cm³ | 8.94 g/cm³ | 8.86 g/cm³ | 8.46 g/cm³ | 8.7 g/cm³ | 8.79 g/cm³ | 8.53 g/cm³ | 8.94 g/cm³ | 7.28 g/cm³ |
| Electrical conductivity, annealed C36000 (Fisk MA36B) | 26 %IACS6 | 58 MS/m | 13 %IACS | 7 %IACS | 25 to 30 %IACS | 15 %IACS | 28 %IACS | > 58 MS/m | > 46.4 MS/m | no data | 56 %IACS | 25 %IACS | 6 %IACS | 13 %IACS | 7 %IACS | 93 %IACS | 58 MS/m |
| Electrical resistivity, annealed C36000 (Fisk MA36B) | 6.63 µΩ·cm7 | no data | 13.33 µΩ·cm | 0.172 µΩ·m | 5.8 to 6.9 μΩ-cm | 8.7×10^-6 ohm·cm | 6.15 µΩ·cm | no data | no data | 37.4 µΩ·cm | 3.08 µΩ·cm | no data | no data | no data | 24.6 microohm-cm | no data | 11.5 µΩ·cm |
| Hardness, half-hard H02 bar, 12.7 mm and under (range) | 60 to 80 HRB20 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Electrical conductivity, half-hard H02 bar, 12.7 mm and under | 26 %IACS21 | 58 MS/m | 13 %IACS | 7 %IACS | 25 to 30 %IACS | 15 %IACS | 28 %IACS | > 58 MS/m | > 46.4 MS/m | no data | 56 %IACS | 25 %IACS | 6 %IACS | 13 %IACS | 7 %IACS | 93 %IACS | 58 MS/m |
| Other measurements | |||||||||||||||||
| Coefficient of thermal expansion, 20 to 300 °C (Fisk MA36B) | 20.5 ppm/K5 | 17.6 ppm/K | 16.2 ppm/K | 15 ppm/K | 17.5 ppm/K | 17.8 µm/(m·°C) | 20 ppm/K | no data | 17.1 ppm/K | 13.2 to 16.2 ppm/K | 18 ppm/K | 21.4 ppm/K | 17.7 ppm/K | 17.4 µm/(m·°C) | 18 um/(m.°C) | 16.5 ppm/K | 22 ppm/K |
| Tensile strength, annealed O60 round rod (minimum) | > 330 MPa8 | 179 to 262 MPa | > 586 MPa | > 585 MPa | 410 to 590 MPa | > 485 MPa | 324 MPa | 180 N/mm2 | 480 to 560 MPa | 358 to 414 MPa | 235 MPa | > 360 MPa | 370 to 430 MPa | 475 to 580 MPa | 538 MPa | > 260 MPa | no data |
| Yield strength, annealed O60 round rod (minimum, 0.5 % extension under load) | > 130 MPa9 | 69 MPa | > 221 MPa | > 295 MPa | 130 to 250 MPa | 550 MPa | 103 MPa | no data | > 450 MPa | 124 to 179 MPa | no data | > 220 MPa | no data | > 350 MPa | 310 MPa | > 205 MPa | no data |
| Elongation, annealed O60 round rod (minimum) | > 15 %10 | 35 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | > 25 % | 17 % | > 8 % | no data |
| Tensile strength, half-hard H02 round rod (minimum) | > 390 MPa11 | 179 to 262 MPa | > 586 MPa | > 585 MPa | 410 to 590 MPa | > 485 MPa | 324 MPa | 180 N/mm2 | 480 to 560 MPa | 358 to 414 MPa | 235 MPa | > 360 MPa | 370 to 430 MPa | 475 to 580 MPa | 538 MPa | > 260 MPa | no data |
| Yield strength, half-hard H02 round rod (minimum, 0.5 % extension under load) | > 170 MPa12 | 69 MPa | > 221 MPa | > 295 MPa | 130 to 250 MPa | 550 MPa | 103 MPa | no data | > 450 MPa | 124 to 179 MPa | no data | > 220 MPa | no data | > 350 MPa | 310 MPa | > 205 MPa | no data |
| Elongation, half-hard H02 round rod (minimum) | > 7 %13 | 35 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | > 25 % | 17 % | > 8 % | no data |
| Tensile strength, hard H04 round rod (minimum) | > 480 MPa14 | 179 to 262 MPa | > 586 MPa | > 585 MPa | 410 to 590 MPa | > 485 MPa | 324 MPa | 180 N/mm2 | 480 to 560 MPa | 358 to 414 MPa | 235 MPa | > 360 MPa | 370 to 430 MPa | 475 to 580 MPa | 538 MPa | > 260 MPa | no data |
| Yield strength, hard H04 round rod (minimum, 0.5 % extension under load) | > 240 MPa15 | 69 MPa | > 221 MPa | > 295 MPa | 130 to 250 MPa | 550 MPa | 103 MPa | no data | > 450 MPa | 124 to 179 MPa | no data | > 220 MPa | no data | > 350 MPa | 310 MPa | > 205 MPa | no data |
| Elongation, hard H04 round rod (minimum) | > 4 %16 | 35 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | > 25 % | 17 % | > 8 % | no data |
| Tensile strength, half-hard H02 bar, 12.7 mm and under (minimum) | > 395 MPa17 | 179 to 262 MPa | > 586 MPa | > 585 MPa | 410 to 590 MPa | > 485 MPa | 324 MPa | 180 N/mm2 | 480 to 560 MPa | 358 to 414 MPa | 235 MPa | > 360 MPa | 370 to 430 MPa | 475 to 580 MPa | 538 MPa | > 260 MPa | no data |
| Yield strength, half-hard H02 bar, 12.7 mm and under (minimum, 0.5 % extension under load) | > 170 MPa18 | 69 MPa | > 221 MPa | > 295 MPa | 130 to 250 MPa | 550 MPa | 103 MPa | no data | > 450 MPa | 124 to 179 MPa | no data | > 220 MPa | no data | > 350 MPa | 310 MPa | > 205 MPa | no data |
| Elongation, half-hard H02 bar, 12.7 mm and under (minimum) | > 7 %19 | 35 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | > 25 % | 17 % | > 8 % | no data |
| Machinability rating, C36000 bar (supplier scale, C36000 = 100) | 100 %22 | no data | 60 - | no data | no data | no data | 30 % | no data | no data | no data | 20 % | 100 % | no data | no data | no data | 85 - | no data |
| Shear modulus, C36000 (typical, Smith) | 37 GPa23 | no data | no data | no data | no data | no data | 41370 MPa | no data | 45 kN/mm2 | no data | no data | no data | no data | no data | 38610 MPa | 44130 MPa | no data |
Why choose it, and why not
Good for
- Machined parts in volume, where machinability rated 100 is the main selection criterion.
- Fittings and connectors that need 330 to 480 MPa minimum tensile strength, chosen by temper.
- Brazed or soldered assemblies: Smith rates the alloy as readily brazed or soldered.
Watch out for
- Lead at 2.5 to 3.0 % puts the alloy outside California's 0.25 % limit for lead-free plumbing brass.
- Dezincification in water and season cracking in ammonia, both caused by the zinc content and by stress.
- Hard H04 round rod stretches only 4 % minimum, which limits forming.
- The shear modulus of 37 GPa is a typical value with no temper stated, and no elastic modulus is recorded (see gaps).
Free-cutting brass C36000 is the machinability reference among brasses, rated 100 on the supplier scale. It conducts at 26 %IACS and gives 330 to 480 MPa minimum tensile strength across the O60 to H04 tempers. Its 2.5 to 3.0 % lead rules it out of California's lead-free plumbing brass, and its zinc content invites dezincification in water and season cracking in ammonia. No corrosion rate, no space-environment result and no elastic modulus were found in the pages read.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| UNS | C36000 |
| EN name | CW603N, CuZn36Pb3 |
| BS | CZ124 (nearest equivalent) |
| CDA | C360 |
| ASTM | B16 |
| Trade name | Free Machining Brass, Free Cutting Brass |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, C36000 (Fisk MA36B) | Value printed in the metric column of a supplier's physical properties table | grade C36000 (Fisk MA36B)temper not stated; one value printed for the alloytemperature not statedunit in source 0.307 lb/in3 (English column) | — |
| 2 | Solidus, C36000 (Fisk MA36B) | Value printed in the metric column of a supplier's physical properties table | grade C36000 (Fisk MA36B)unit in source 1,750 °Fpressure not stated | — |
| 3 | Liquidus, C36000 (Fisk MA36B) | Value printed in the metric column of a supplier's physical properties table | grade C36000 (Fisk MA36B)unit in source 1,920 °Fpressure not stated | — |
| 4 | Thermal conductivity at 20 °C, C36000 (Fisk MA36B) | Value printed in the metric column of a supplier's physical properties table | grade C36000 (Fisk MA36B)temperature 20 °Ctemper not stated; one value printed for the alloy | — |
| 5 | Coefficient of thermal expansion, 20 to 300 °C (Fisk MA36B) | Printed as per °C; this is 10^-6 per kelvin, the same unit as ppm/K, so the number is copied without conversion | grade C36000 (Fisk MA36B)temperature 20 to 300 °Ctemper not statedunit in source 20.5 per °C (20-300 °C) | — |
| 6 | Electrical conductivity, annealed C36000 (Fisk MA36B) | Value printed in the English column of a supplier's physical properties table; the metric column for the same row (0.15 MS·cm) does not convert to 26 %IACS and is not used | grade C36000 (Fisk MA36B)temper annealed (O60)temperature 68 °F (20 °C)unit in source 26% IACS @ 68 °F (English column) | — |
| 7 | Electrical resistivity, annealed C36000 (Fisk MA36B) | Value printed in the metric column of a supplier's physical properties table | grade C36000 (Fisk MA36B)temper annealed (O60)temperature 20 °Cunit in source 39.9 Ω·cir-mil/ft @ 68 °F (English column) | — |
| 8 | Tensile strength, annealed O60 round rod (minimum) | Minimum value printed in a supplier's pretempered round rod table, metric block | grade C36000 (Fisk MA36B)temper O60, annealed (soft)product form round rod, mill limits 1.59 to 6.35 mmmeasure minimumunit in source 48.0 ksi (English block) | — |
| 9 | Yield strength, annealed O60 round rod (minimum, 0.5 % extension under load) | Minimum value printed in a supplier's pretempered round rod table; the yield definition is 0.5 % extension under load, not the 0.2 % offset | grade C36000 (Fisk MA36B)temper O60, annealed (soft)product form round rod, mill limits 1.59 to 6.35 mmmeasure minimum, 0.5 % extension under loadunit in source 20.0 ksi (English block) | — |
| 10 | Elongation, annealed O60 round rod (minimum) | Value printed in a supplier's pretempered round rod table, metric block | grade C36000 (Fisk MA36B)temper O60, annealed (soft)product form round rod, mill limits 1.59 to 6.35 mmgauge length 1 in (1 GL column header) | — |
| 11 | Tensile strength, half-hard H02 round rod (minimum) | Minimum value printed in a supplier's pretempered round rod table, metric block | grade C36000 (Fisk MA36B)temper H02, half hard (1/2 hard)product form round rod, mill limits 1.59 to 6.35 mmmeasure minimumunit in source 57.0 ksi (English block) | — |
| 12 | Yield strength, half-hard H02 round rod (minimum, 0.5 % extension under load) | Minimum value printed in a supplier's pretempered round rod table; the yield definition is 0.5 % extension under load | grade C36000 (Fisk MA36B)temper H02, half hard (1/2 hard)product form round rod, mill limits 1.59 to 6.35 mmmeasure minimum, 0.5 % extension under loadunit in source 25.0 ksi (English block) | — |
| 13 | Elongation, half-hard H02 round rod (minimum) | Value printed in a supplier's pretempered round rod table, metric block | grade C36000 (Fisk MA36B)temper H02, half hard (1/2 hard)product form round rod, mill limits 1.59 to 6.35 mmgauge length 1 in (1 GL column header) | — |
| 14 | Tensile strength, hard H04 round rod (minimum) | Minimum value printed in a supplier's pretempered round rod table, metric block | grade C36000 (Fisk MA36B)temper H04, hardproduct form round rod, mill limits 4.77 to 6.35 mmmeasure minimumunit in source 70.0 ksi (English block) | — |
| 15 | Yield strength, hard H04 round rod (minimum, 0.5 % extension under load) | Minimum value printed in a supplier's pretempered round rod table; the yield definition is 0.5 % extension under load | grade C36000 (Fisk MA36B)temper H04, hardproduct form round rod, mill limits 4.77 to 6.35 mmmeasure minimum, 0.5 % extension under loadunit in source 35.0 ksi (English block) | — |
| 16 | Elongation, hard H04 round rod (minimum) | Value printed in a supplier's pretempered round rod table, metric block | grade C36000 (Fisk MA36B)temper H04, hardproduct form round rod, mill limits 4.77 to 6.35 mmgauge length 1 in (1 GL column header) | — |
| 17 | Tensile strength, half-hard H02 bar, 12.7 mm and under (minimum) | Minimum value printed in a manufacturer's comparison table (Model 3 against C36000), C36000 column | grade C36000temper H02, 1/2 hardproduct form bar, diameter or distance between parallel surfaces 12.7 mm and undermeasure minimum | — |
| 18 | Yield strength, half-hard H02 bar, 12.7 mm and under (minimum, 0.5 % extension under load) | Minimum value printed in a manufacturer's comparison table, C36000 column; the yield definition is 0.5 % extension under load | grade C36000temper H02, 1/2 hardproduct form bar, diameter or distance between parallel surfaces 12.7 mm and undermeasure minimum, 0.5 % extension under load | — |
| 19 | Elongation, half-hard H02 bar, 12.7 mm and under (minimum) | Minimum value printed in a manufacturer's comparison table, C36000 column | grade C36000temper H02, 1/2 hardproduct form bar, 12.7 mm and undermeasure minimum | — |
| 20 | Hardness, half-hard H02 bar, 12.7 mm and under (range) | Range printed in a manufacturer's comparison table, C36000 column (Rockwell B scale as printed as HRB) | grade C36000temper H02, 1/2 hardproduct form bar, 12.7 mm and under | — |
| 21 | Electrical conductivity, half-hard H02 bar, 12.7 mm and under | Value printed in a manufacturer's comparison table, C36000 column; the page prints the unit as % AICS, read here as %IACS | grade C36000temper H02, 1/2 hardproduct form bar, 12.7 mm and under | — |
| 22 | Machinability rating, C36000 bar (supplier scale, C36000 = 100) | Index printed in a manufacturer's comparison table; it is a relative rating, not a measured property | grade C36000temper not statedproduct form barbasis relative index with C36000 defined as 100 % | — |
| 23 | Shear modulus, C36000 (typical, Smith) | Typical value printed in a supplier's datasheet, Mechanical Properties table | grade C36000temper not stated (typical value)temperature not stated | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Water containing chlorides, high water temperatures or soft water (dezincification) | moderate | Brass with more than 15 % zinc dezincifies: zinc leaves the alloy and a weak copper layer is left.1 |
| Ammonia or amine atmospheres with tensile stress (season cracking) | moderate | Brass can crack in ammonia when it is under tensile stress, and cold work leaves the stress that causes it.2 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Water containing chlorides, high water temperatures or soft water (dezincification) | Aviva says that in Cu-Zn alloys with more than 15 % zinc, dezincification selectively removes the zinc, leaving a relatively porous and weak layer of copper and copper oxide, and that this can create catastrophic failures. Wikipedia says dezincification-resistant brasses are used where the risk of corrosion is large, for example with high water temperatures, chlorides or soft water. C36000 has about 35 % zinc (nominal Zn 35.4 % on the National Bronze page). | basis qualitative description; no depth, rate or test time for C36000 is printed in the sourceszinc content about 35 % (nominal, National Bronze) |
| 2 | Ammonia or amine atmospheres with tensile stress (season cracking) | The Hendrix Group says stress corrosion cracking needs a sufficiently high tensile stress together with a specific corrosive environment, which for brasses is usually ammonia or amines. Cold working such as pressing, spinning, drawing and bending leaves internal stresses that can lead to cracking unless a stress-relief heat treatment removes them. Cracks are usually localised, and may be accompanied by black staining where ammonia was involved. Wikipedia says brass is susceptible to stress corrosion cracking, especially from ammonia, and that the problem was first found in brass cartridges in the 1920s. | basis qualitative description for brasses in general; no threshold stress or time to crack for C36000 is printedtest example Accelerated test cited on the page: axially loaded specimens in air with 10 % ammonia and 3.7 % water vapour at 35 °C (a test condition, not a service limit) |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The lead in C36000 is the main health concern in these sources. They give health effects of lead but no exposure limit for brass dust.
- Lead in the alloy
- C36000 has 2.5 to 3.0 % lead (Aviva and Fisk limits; Wikipedia gives 2.5 to 3.7 % for C360). The ATSDR says lead can affect almost every organ and system, and the U.S. Department of Health and Human Services considers lead and lead compounds reasonably anticipated to be human carcinogens.
- Plumbing
- California defines lead-free brass as containing no more than 0.25 % lead (AB 1953), down from 4.0 % on 1 January 2010 (Wikipedia). Aviva says the U.S. plumbing industry replaced C36000 with lead-free alternatives from January 2010.
If it fails
The failure routes in these sources are chemical (water and ammonia) and, for the hard temper, mechanical.
- Dezincification
- In water with chlorides, high temperature or soft quality, zinc leaves the alloy and a weak copper layer remains. Aviva says this can create catastrophic failures.
- Season cracking
- Cold work leaves stress, and in an ammonia or amine atmosphere the alloy can crack. The Hendrix Group describes the crack pattern for simple alpha brass, not for C36000.
- Hard temper
- The H04 hard temper reaches 480 MPa minimum tensile strength, but its elongation is only 4 % minimum, so there is little room for bending.
Handling and storage
- Pick the temper
- Annealed O60 round rod has 330 MPa minimum tensile and 15 % elongation. Half-hard H02 has 390 MPa and 7 %. Hard H04 has 480 MPa and 4 %.
- Stress relief
- Stress-relieve parts after cold work, as the Hendrix Group advises, and keep them out of ammonia and amine atmospheres.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Dezincification of brass in watermoderate severity | Water with chlorides, high temperature or soft quality, in a brass with about 35 % zincZinc is removed, leaving a porous, weak copper and copper-oxide layer. Aviva says this can create catastrophic failures. |
| Season cracking in ammoniamoderate severity | Tensile stress from cold work (pressing, drawing, bending) or assembly, together with an ammonia or amine atmosphereLocalised cracking, which the Hendrix Group says may be accompanied by black staining where ammonia was involved. Its crack pattern is described for simple alpha brass, not for C36000. |
| Brittle forming in the hard temperlow severity | Forming or bending round rod in the hard H04 temperElongation is 4.00 % minimum for H04 round rod (4.77 to 6.35 mm), against 15.0 % annealed. The source gives no forming limit. |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| Use in potable-water plumbing fittings | Aviva says the U.S. plumbing industry has replaced traditional free-machining brass C36000 with lead-free alternatives since January 2010, backed by California legislation AB 1953. |
Handling and storage
- Specify the temper on the drawing or order: annealed O60 rod gives 330 MPa minimum tensile and 15 % elongation; half-hard H02 gives 390 MPa and 7 %; hard H04 gives 480 MPa and 4 %.
- Stress-relieve parts after cold work (pressing, spinning, drawing, bending). The Hendrix Group says residual stresses from cold work can cause cracking unless they are removed or substantially reduced.
- Keep parts out of ammonia and amine atmospheres in service; the Hendrix Group names these as the usual cracking environments for brass.
- Avoid exposure to lead. The ATSDR advises avoiding sources of lead and says a blood test is available for people who may have been exposed.
Mitigations
- Aviva's Model 3 alloy has less than 15 % zinc and is described as a true dezincification-resistant brass.
- Where service and process requirements allow, choose less susceptible brasses: low zinc rather than high zinc alloys, and aluminium brass rather than admiralty. The Hendrix Group says this improves resistance to stress corrosion cracking.
Supply and geography
How common the raw materials are and where they come from.
Copper (mine production, copper content, 2025e), the main metal in brass
- Top producers (2025)
- Chile 23%, Congo (Kinshasa) 13.9%, Peru 11.7%, China 7.8%, Russia 5.7%
- Critical mineral lists
- US: listed
- Recycling
- USGS: brass and wire-rod mills accounted for about 80 % of the copper recovered from scrap, and copper recovered from scrap contributed about 30 % of U.S. copper supply.
Zinc (mine production, zinc content, 2025e), about 35 % of brass
- Top producers (2025)
- China 31.5%, Peru 11.5%, Australia 8.5%, India 6.7%, Mexico 6%
- Recycling
- USGS: refined zinc produced in the United States was recovered from secondary materials, including galvanizing residues and crude zinc oxide from electric arc furnace dust. U.S. net import reliance for refined zinc was 73 % of apparent consumption in 2025e.
- Substitutes
- USGS: aluminum and plastics substitute for galvanized sheet in automobiles, and many elements substitute for zinc in chemical, electronic and pigment uses. The summary names no substitute for zinc in brass.
Lead (mine production, 2025e), about 2.5 to 3 % of brass
- Top producers (2025)
- China 42.2%, Peru 6.4%, United States 6.2%, Russia 5.8%, Mexico 4.4%
- Critical mineral lists
- US: listed
- Recycling
- USGS: nearly all secondary lead was recovered from old scrap, mostly lead-acid batteries.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
Show the full YAML
spore: profile
id: brass-c360
spore_version: 0.2
family: copper-alloys
name: Free-cutting brass C36000
abbreviation: C360
role: free-cutting machining alloy
category: metals
type: copper-alloys
summary: |
Free-cutting brass C36000 (UNS C36000, CuZn36Pb3) is a copper-zinc alloy with 2.5 to 3.0 % lead, made for high-speed screw-machine work. Its machinability is rated 100 on the supplier scale. Its density is 8.5 g/cm3, its electrical conductivity is 26 %IACS and its thermal conductivity is 116 W/(m·K) at 20 °C. Strength depends on temper: round rod has a minimum tensile strength of 330 MPa annealed (O60), 390 MPa half hard (H02) and 480 MPa hard (H04), and its elongation falls from 15 % to 4 % across those tempers. The alloy dezincifies in water and can crack under tensile stress in ammonia, and its lead content keeps it out of California's lead-free plumbing brass (limit 0.25 % lead). For the pure metal see the [copper profile](/profiles/copper/).
best_for: High-volume machined parts such as screw-machine products, fasteners and valve components, where machinability rated 100 matters most
weakest_at: Corrosion in water (dezincification, about 35 % zinc) and in ammonia (season cracking), plus its 2.5 to 3.0 % lead content
identity:
formula: 'CuZn36Pb3, UNS C36000: copper 60.0 to 63.0 wt%, lead 2.5 to 3.0 wt%, iron 0.35 wt% maximum, zinc remainder'
source: aviva-c36000
where: Chemical Composition limits on the Aviva product page (Cu 60-63, Pb 2.5-3.0, Fe 0.35 max, Zn rem); the same limits appear on the Fisk MA36B page. Wikipedia's C360 row gives lead 2.5 to 3.7 wt%.
designations:
- system: UNS
code: C36000
source: fisk-ma36b
where: 'Page title: C36000 Free-Cutting Brass (CuZn36Pb3)'
- system: CDA
code: C360
source: natbronze-c36000
where: 'Page title: C36000 Free Cutting Brass Bar / C360 Brass / Free Machining Brass'
- system: EN name
code: CW603N
source: wieland-brass-alloys
where: Brass alloys table, row Z23 (EN designation CuZn36Pb3), EN No. column
- system: EN name
code: CuZn36Pb3
source: fisk-ma36b
where: 'Page title: C36000 Free-Cutting Brass (CuZn36Pb3)'
- system: BS
code: CZ124
note: nearest equivalent
source: aalco-copper-brass-bronze
where: Wrought copper-zinc-lead alloys table, row CuZn36Pb3 (CW603N), Old BS Equivalent column; BS to EN conversion table, row CuZn36Pb3
- system: ASTM
code: B16
source: fisk-ma36b
where: Specifications line (ASTM B16, EN 12164, EN 12166); product form not stated
- system: Trade name
code: Free Machining Brass
source: natbronze-c36000
where: 'Page title: C36000 Free Cutting Brass Bar / C360 Brass / Free Machining Brass'
- system: Trade name
code: Free Cutting Brass
source: fisk-ma36b
where: 'Page title: C36000 Free-Cutting Brass (CuZn36Pb3)'
tags:
environments: []
stresses: []
applications:
- mechanisms
- habitats-and-suits
properties:
- benchmark: density
label: Density, C36000 (Fisk MA36B)
value: 8.5
unit: g/cm3
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: not stated; one value printed for the alloy
temperature: not stated
unit_in_source: 0.307 lb/in3 (English column)
method: Value printed in the metric column of a supplier's physical properties table
status: ground
source: fisk-ma36b
where: Physical Properties table, Density row, metric column
- benchmark: melting_point
label: Solidus, C36000 (Fisk MA36B)
value: 954
unit: °C
scope: material
conditions:
grade: C36000 (Fisk MA36B)
unit_in_source: 1,750 °F
pressure: not stated
method: Value printed in the metric column of a supplier's physical properties table
status: ground
source: fisk-ma36b
where: Physical Properties table, Melting Point (Solidus) row, metric column
- benchmark: melting_point
label: Liquidus, C36000 (Fisk MA36B)
value: 1049
unit: °C
scope: material
conditions:
grade: C36000 (Fisk MA36B)
unit_in_source: 1,920 °F
pressure: not stated
method: Value printed in the metric column of a supplier's physical properties table
status: ground
source: fisk-ma36b
where: Physical Properties table, Melting Point (Liquidus) row, metric column
- benchmark: thermal_conductivity
label: Thermal conductivity at 20 °C, C36000 (Fisk MA36B)
value: 116
unit: W/(m·K)
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temperature: 20 °C
temper: not stated; one value printed for the alloy
method: Value printed in the metric column of a supplier's physical properties table
status: ground
source: fisk-ma36b
where: Physical Properties table, Thermal Conductivity row, metric column
- benchmark: cte
label: Coefficient of thermal expansion, 20 to 300 °C (Fisk MA36B)
value: 20.5
unit: ppm/K
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temperature: 20 to 300 °C
temper: not stated
unit_in_source: 20.5 per °C (20-300 °C)
method: Printed as per °C; this is 10^-6 per kelvin, the same unit as ppm/K, so the number is copied without conversion
status: ground
source: fisk-ma36b
where: Physical Properties table, Coefficient of Thermal Expansion row, metric column
- benchmark: electrical_conductivity
label: Electrical conductivity, annealed C36000 (Fisk MA36B)
value: 26
unit: '%IACS'
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: annealed (O60)
temperature: 68 °F (20 °C)
unit_in_source: 26% IACS @ 68 °F (English column)
method: Value printed in the English column of a supplier's physical properties table; the metric column for the same row (0.15 MS·cm) does not convert to 26 %IACS and is not used
status: ground
source: fisk-ma36b
where: Physical Properties table, Electrical Conductivity (Annealed) row
- benchmark: electrical_resistivity
label: Electrical resistivity, annealed C36000 (Fisk MA36B)
value: 6.63
unit: µΩ·cm
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: annealed (O60)
temperature: 20 °C
unit_in_source: 39.9 Ω·cir-mil/ft @ 68 °F (English column)
method: Value printed in the metric column of a supplier's physical properties table
status: ground
source: fisk-ma36b
where: Physical Properties table, Electrical Resistivity (Annealed) row, metric column
- benchmark: ultimate_tensile_strength
label: Tensile strength, annealed O60 round rod (minimum)
value: 330
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: O60, annealed (soft)
product_form: round rod, mill limits 1.59 to 6.35 mm
measure: minimum
unit_in_source: 48.0 ksi (English block)
method: Minimum value printed in a supplier's pretempered round rod table, metric block
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row Annealed O60, column Tensile strength (MPa) Min
- benchmark: yield_strength
label: Yield strength, annealed O60 round rod (minimum, 0.5 % extension under load)
value: 130
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: O60, annealed (soft)
product_form: round rod, mill limits 1.59 to 6.35 mm
measure: minimum, 0.5 % extension under load
unit_in_source: 20.0 ksi (English block)
method: Minimum value printed in a supplier's pretempered round rod table; the yield definition is 0.5 % extension under load, not the 0.2 % offset
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row Annealed O60, column Yield strength 0.5% EUL (MPa) Min
- benchmark: elongation
label: Elongation, annealed O60 round rod (minimum)
value: 15
bound: lower
unit: '%'
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: O60, annealed (soft)
product_form: round rod, mill limits 1.59 to 6.35 mm
gauge_length: 1 in (1 GL column header)
method: Value printed in a supplier's pretempered round rod table, metric block
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row Annealed O60, column Elongation (%) 1 in GL
- benchmark: ultimate_tensile_strength
label: Tensile strength, half-hard H02 round rod (minimum)
value: 390
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: H02, half hard (1/2 hard)
product_form: round rod, mill limits 1.59 to 6.35 mm
measure: minimum
unit_in_source: 57.0 ksi (English block)
method: Minimum value printed in a supplier's pretempered round rod table, metric block
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row H02, column Tensile strength (MPa) Min
- benchmark: yield_strength
label: Yield strength, half-hard H02 round rod (minimum, 0.5 % extension under load)
value: 170
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: H02, half hard (1/2 hard)
product_form: round rod, mill limits 1.59 to 6.35 mm
measure: minimum, 0.5 % extension under load
unit_in_source: 25.0 ksi (English block)
method: Minimum value printed in a supplier's pretempered round rod table; the yield definition is 0.5 % extension under load
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row H02, column Yield strength 0.5% EUL (MPa) Min
- benchmark: elongation
label: Elongation, half-hard H02 round rod (minimum)
value: 7
bound: lower
unit: '%'
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: H02, half hard (1/2 hard)
product_form: round rod, mill limits 1.59 to 6.35 mm
gauge_length: 1 in (1 GL column header)
method: Value printed in a supplier's pretempered round rod table, metric block
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row H02, column Elongation (%) 1 in GL
- benchmark: ultimate_tensile_strength
label: Tensile strength, hard H04 round rod (minimum)
value: 480
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: H04, hard
product_form: round rod, mill limits 4.77 to 6.35 mm
measure: minimum
unit_in_source: 70.0 ksi (English block)
method: Minimum value printed in a supplier's pretempered round rod table, metric block
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row Hard H04, column Tensile strength (MPa) Min
- benchmark: yield_strength
label: Yield strength, hard H04 round rod (minimum, 0.5 % extension under load)
value: 240
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: H04, hard
product_form: round rod, mill limits 4.77 to 6.35 mm
measure: minimum, 0.5 % extension under load
unit_in_source: 35.0 ksi (English block)
method: Minimum value printed in a supplier's pretempered round rod table; the yield definition is 0.5 % extension under load
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row Hard H04, column Yield strength 0.5% EUL (MPa) Min
- benchmark: elongation
label: Elongation, hard H04 round rod (minimum)
value: 4
bound: lower
unit: '%'
scope: material
conditions:
grade: C36000 (Fisk MA36B)
temper: H04, hard
product_form: round rod, mill limits 4.77 to 6.35 mm
gauge_length: 1 in (1 GL column header)
method: Value printed in a supplier's pretempered round rod table, metric block
status: ground
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, row Hard H04, column Elongation (%) 1 in GL
- benchmark: ultimate_tensile_strength
label: Tensile strength, half-hard H02 bar, 12.7 mm and under (minimum)
value: 395
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000
temper: H02, 1/2 hard
product_form: bar, diameter or distance between parallel surfaces 12.7 mm and under
measure: minimum
method: Minimum value printed in a manufacturer's comparison table (Model 3 against C36000), C36000 column
status: ground
source: aviva-c36000
where: Model 3 Compared to C36000 table, row H02 1/2 Hard, size 1/2 in (12.7 mm and under), column Tensile Strength min C36000
- benchmark: yield_strength
label: Yield strength, half-hard H02 bar, 12.7 mm and under (minimum, 0.5 % extension under load)
value: 170
bound: lower
unit: MPa
scope: material
conditions:
grade: C36000
temper: H02, 1/2 hard
product_form: bar, diameter or distance between parallel surfaces 12.7 mm and under
measure: minimum, 0.5 % extension under load
method: Minimum value printed in a manufacturer's comparison table, C36000 column; the yield definition is 0.5 % extension under load
status: ground
source: aviva-c36000
where: Model 3 Compared to C36000 table, row H02 1/2 Hard, size 1/2 in and under, column Yield Strength at 0.5% Extension Under Load min C36000
- benchmark: elongation
label: Elongation, half-hard H02 bar, 12.7 mm and under (minimum)
value: 7
bound: lower
unit: '%'
scope: material
conditions:
grade: C36000
temper: H02, 1/2 hard
product_form: bar, 12.7 mm and under
measure: minimum
method: Minimum value printed in a manufacturer's comparison table, C36000 column
status: ground
source: aviva-c36000
where: Model 3 Compared to C36000 table, row H02 1/2 Hard, size 1/2 in and under, column Elongation min C36000
- benchmark: hardness_rockwell_b
label: Hardness, half-hard H02 bar, 12.7 mm and under (range)
value: 60
value_high: 80
bound: range
unit: HRB
scope: material
conditions:
grade: C36000
temper: H02, 1/2 hard
product_form: bar, 12.7 mm and under
method: Range printed in a manufacturer's comparison table, C36000 column (Rockwell B scale as printed as HRB)
status: ground
source: aviva-c36000
where: Model 3 Compared to C36000 table, row H02 1/2 Hard, size 1/2 in and under, column Hardness (HRB) C36000
- benchmark: electrical_conductivity
label: Electrical conductivity, half-hard H02 bar, 12.7 mm and under
value: 26
unit: '%IACS'
scope: material
conditions:
grade: C36000
temper: H02, 1/2 hard
product_form: bar, 12.7 mm and under
method: Value printed in a manufacturer's comparison table, C36000 column; the page prints the unit as % AICS, read here as %IACS
status: ground
source: aviva-c36000
where: Model 3 Compared to C36000 table, row H02 1/2 Hard, size 1/2 in and under, column Conductivity C36000
- benchmark: machinability_rating
label: Machinability rating, C36000 bar (supplier scale, C36000 = 100)
value: 100
unit: '%'
scope: material
conditions:
grade: C36000
temper: not stated
product_form: bar
basis: relative index with C36000 defined as 100 %
method: Index printed in a manufacturer's comparison table; it is a relative rating, not a measured property
status: ground
source: aviva-c36000
where: Model 3 Compared to C36000 table, row H02 1/2 Hard, column Machinability C36000
- benchmark: shear_modulus
label: Shear modulus, C36000 (typical, Smith)
value: 37
unit: GPa
scope: material
conditions:
grade: C36000
temper: not stated (typical value)
temperature: not stated
method: Typical value printed in a supplier's datasheet, Mechanical Properties table
status: ground
source: smith-c36000
where: Mechanical Properties (typical) table, Shear Modulus column
corrosion:
- environment: Water containing chlorides, high water temperatures or soft water (dezincification)
headline: 'Brass with more than 15 % zinc dezincifies: zinc leaves the alloy and a weak copper layer is left.'
effect: Aviva says that in Cu-Zn alloys with more than 15 % zinc, dezincification selectively removes the zinc, leaving a relatively porous and weak layer of copper and copper oxide, and that this can create catastrophic failures. Wikipedia says dezincification-resistant brasses are used where the risk of corrosion is large, for example with high water temperatures, chlorides or soft water. C36000 has about 35 % zinc (nominal Zn 35.4 % on the National Bronze page).
rating: moderate
conditions:
basis: qualitative description; no depth, rate or test time for C36000 is printed in the sources
zinc_content: about 35 % (nominal, National Bronze)
source: aviva-c36000
where: Footnote to the Model 3 comparison table (asterisk note on dezincification)
- environment: Ammonia or amine atmospheres with tensile stress (season cracking)
headline: Brass can crack in ammonia when it is under tensile stress, and cold work leaves the stress that causes it.
effect: The Hendrix Group says stress corrosion cracking needs a sufficiently high tensile stress together with a specific corrosive environment, which for brasses is usually ammonia or amines. Cold working such as pressing, spinning, drawing and bending leaves internal stresses that can lead to cracking unless a stress-relief heat treatment removes them. Cracks are usually localised, and may be accompanied by black staining where ammonia was involved. Wikipedia says brass is susceptible to stress corrosion cracking, especially from ammonia, and that the problem was first found in brass cartridges in the 1920s.
rating: moderate
conditions:
basis: qualitative description for brasses in general; no threshold stress or time to crack for C36000 is printed
test_example: 'Accelerated test cited on the page: axially loaded specimens in air with 10 % ammonia and 3.7 % water vapour at 35 °C (a test condition, not a service limit)'
source: hgh-scc
where: Sections on the environment, morphology, cold working and effect of zinc content
risks:
hazards:
- text: 'Lead: C36000 contains 2.5 to 3.0 wt% lead (Aviva and Fisk limits). The ATSDR ToxFAQ for lead says lead can affect almost every organ and system, that the U.S. Department of Health and Human Services considers lead and lead compounds reasonably anticipated to be human carcinogens, and that high exposure in pregnant women may cause miscarriage. No GHS code for the alloy was read.'
ghs: []
source: atsdr-lead
where: ToxFAQs sections How can lead affect my health, How can lead affect children and Can lead cause cancer
- text: California defines lead-free brass as containing no more than 0.25 % lead under AB 1953. The limit was cut from 4.0 % on 1 January 2010 (Wikipedia). C36000, at 2.5 to 3.0 % lead, is far outside that limit.
ghs: []
source: wiki-brass
where: Lead content section, and the table row California lead-free brass
failure_risks:
- mode: Dezincification of brass in water
trigger: Water with chlorides, high temperature or soft quality, in a brass with about 35 % zinc
consequence: Zinc is removed, leaving a porous, weak copper and copper-oxide layer. Aviva says this can create catastrophic failures.
severity: moderate
source: aviva-c36000
where: Footnote to the Model 3 comparison table
- mode: Season cracking in ammonia
trigger: Tensile stress from cold work (pressing, drawing, bending) or assembly, together with an ammonia or amine atmosphere
consequence: Localised cracking, which the Hendrix Group says may be accompanied by black staining where ammonia was involved. Its crack pattern is described for simple alpha brass, not for C36000.
severity: moderate
source: hgh-scc
where: Sections on morphology and stress-corrosion cracking in brass
- mode: Brittle forming in the hard temper
trigger: Forming or bending round rod in the hard H04 temper
consequence: Elongation is 4.00 % minimum for H04 round rod (4.77 to 6.35 mm), against 15.0 % annealed. The source gives no forming limit.
severity: low
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block, rows Hard H04 and Annealed O60, column Elongation (%) 1 in GL
side_effects:
- text: Aviva says the U.S. plumbing industry has replaced traditional free-machining brass C36000 with lead-free alternatives since January 2010, backed by California legislation AB 1953.
affects: Use in potable-water plumbing fittings
source: aviva-c36000
where: Lead-free brass section of the Aviva page
handling:
- text: 'Specify the temper on the drawing or order: annealed O60 rod gives 330 MPa minimum tensile and 15 % elongation; half-hard H02 gives 390 MPa and 7 %; hard H04 gives 480 MPa and 4 %.'
source: fisk-ma36b
where: Round Rod - Pretempered table, metric block
- text: Stress-relieve parts after cold work (pressing, spinning, drawing, bending). The Hendrix Group says residual stresses from cold work can cause cracking unless they are removed or substantially reduced.
source: hgh-scc
where: Cold working section
- text: Keep parts out of ammonia and amine atmospheres in service; the Hendrix Group names these as the usual cracking environments for brass.
source: hgh-scc
where: Environment section
- text: Avoid exposure to lead. The ATSDR advises avoiding sources of lead and says a blood test is available for people who may have been exposed.
source: atsdr-lead
where: How can I protect my family from lead exposure; Can I get a medical test to check for lead
mitigations:
- text: Aviva's Model 3 alloy has less than 15 % zinc and is described as a true dezincification-resistant brass.
source: aviva-c36000
where: Model 3 footnote
- text: 'Where service and process requirements allow, choose less susceptible brasses: low zinc rather than high zinc alloys, and aluminium brass rather than admiralty. The Hendrix Group says this improves resistance to stress corrosion cracking.'
source: hgh-scc
where: Mitigation paragraph on selecting less susceptible brasses
uses:
- application: mechanisms
device: Automatic screw-machine products and fasteners
example: National Bronze lists screw machine products and fasteners as applications of C36000. Smith lists machine screw parts and high-volume parts.
source: natbronze-c36000
where: Applications list
- application: habitats-and-suits
device: Plumbing components, fittings, adaptors and fluid connectors (terrestrial use)
example: Smith lists plumbing components, fittings and adaptors, and fluid connectors. National Bronze lists fittings and fluid connectors. No source names a space or habitat system; this application tag is our mapping.
source: smith-c36000
where: Key Features and Applications list
supply:
- subject: Copper (mine production, copper content, 2025e), the main metal in brass
producers:
- country: Chile
share_percent: 23
year: 2025
- country: Congo (Kinshasa)
share_percent: 13.9
year: 2025
- country: Peru
share_percent: 11.7
year: 2025
- country: China
share_percent: 7.8
year: 2025
- country: Russia
share_percent: 5.7
year: 2025
critical_lists:
- list: U.S. Final 2025 List of Critical Minerals (copper added, per the USGS copper summary)
listed: true
recycling: 'USGS: brass and wire-rod mills accounted for about 80 % of the copper recovered from scrap, and copper recovered from scrap contributed about 30 % of U.S. copper supply.'
substitutes: []
source: usgs-mcs2026-copper
where: World Mine and Refinery Production and Reserves table, mine production 2025e (world total 23,000 thousand t; shares calculated by Space Mushroom from the printed values 5,300, 3,200, 2,700, 1,800 and 1,300 thousand t); Critical minerals paragraph; Recycling paragraph
- subject: Zinc (mine production, zinc content, 2025e), about 35 % of brass
producers:
- country: China
share_percent: 31.5
year: 2025
- country: Peru
share_percent: 11.5
year: 2025
- country: Australia
share_percent: 8.5
year: 2025
- country: India
share_percent: 6.7
year: 2025
- country: Mexico
share_percent: 6
year: 2025
critical_lists: []
recycling: 'USGS: refined zinc produced in the United States was recovered from secondary materials, including galvanizing residues and crude zinc oxide from electric arc furnace dust. U.S. net import reliance for refined zinc was 73 % of apparent consumption in 2025e.'
substitutes:
- 'USGS: aluminum and plastics substitute for galvanized sheet in automobiles, and many elements substitute for zinc in chemical, electronic and pigment uses. The summary names no substitute for zinc in brass.'
source: usgs-mcs2026-zinc
where: World Mine Production and Reserves table, 2025e (world total rounded 13,000 thousand t; shares calculated by Space Mushroom from the printed values 4,100, 1,500, 1,100, 870 and 780 thousand t); Recycling; Substitutes; Domestic Production and Use (brass and bronze as the second use of zinc)
- subject: Lead (mine production, 2025e), about 2.5 to 3 % of brass
producers:
- country: China
share_percent: 42.2
year: 2025
- country: Peru
share_percent: 6.4
year: 2025
- country: United States
share_percent: 6.2
year: 2025
- country: Russia
share_percent: 5.8
year: 2025
- country: Mexico
share_percent: 4.4
year: 2025
critical_lists:
- list: U.S. Final 2025 List of Critical Minerals (lead added, per the Critical minerals paragraph of the USGS copper summary)
listed: true
recycling: 'USGS: nearly all secondary lead was recovered from old scrap, mostly lead-acid batteries.'
substitutes: []
source: usgs-mcs2026-lead
where: World Mine Production and Reserves table, 2025e (world total rounded 4,500 thousand t; shares calculated by Space Mushroom from the printed values 1,900, 290, 280, 260 and 200 thousand t; Australia's 2025e figure did not extract cleanly from the text and is not in the list); Recycling paragraph
documents:
- title: 'Fisk Alloy MA36B: C36000 free-cutting brass (CuZn36Pb3), physical properties, pretempered round rod table, composition'
type: datasheet
url: https://fiskalloy.com/product/ma36b/
- title: 'Aviva Metals: C36000 free-machining brass, with Model 3 comparison table and dezincification note'
type: datasheet
url: https://avivametals.com/products/c36000-free-machining-brass-free-cutting-brass
- title: 'Smiths Metal Centres: C36000 free-machining brass product datasheet'
type: datasheet
url: https://www.smithmetal.com/pdf/brass/c36000.pdf
year: 2023
- title: 'National Bronze: C36000 Free Cutting Brass Bar, applications and composition'
type: datasheet
url: https://nationalbronze.com/C36000_Free_Cutting_Brass.php
- title: 'Wikipedia: Brass (lead content, dezincification, season cracking, alloy composition table)'
type: database
url: https://en.wikipedia.org/wiki/Brass
year: 2026
- title: 'The Hendrix Group archive: stress corrosion cracking (season cracking) of brasses'
type: report
url: https://hghouston.com/archive/material-property-data/copper-and-copper-alloys/brasses/sc-cracking
- title: 'ATSDR ToxFAQs: Lead'
type: report
url: https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=93&toxid=22
- title: 'USGS Mineral Commodity Summaries 2026: Copper'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Zinc'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Lead'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lead.pdf
year: 2026
- title: 'Wieland: brass alloys, machining brass table (EN designation, EN No., ASTM UNS-No., JIS-No.)'
type: datasheet
url: https://www.wieland.com/products/brass-alloys
- title: 'Aalco Product Guide: copper, brass and bronze, wrought copper-zinc-lead alloys and BS to EN conversion table'
type: datasheet
url: https://www.aalco.co.uk/literature/files/aalco-copper-brass-bronze.pdf
gaps:
- Elastic (Young's) modulus not recorded. The Fisk page prints the modulus of elasticity as 97 Mpa and 14 ksi, which is about 1000 times too low for brass, so the figure is treated as a printing error; no other source for the elastic modulus was read.
- No GHS classification or exposure limit for lead was read. PubChem, NIOSH, OSHA and the ATSDR lead profile returned challenge or rejection pages to the fetcher, so the lead hazard rests on the ATSDR ToxFAQ and Wikipedia.
- 'Lead content range differs by source: Aviva, Fisk and National Bronze give 2.5 to 3.0 wt% lead, while Wikipedia''s C360 row gives 2.5 to 3.7 wt%. The ASTM B16 text (sold) and the EN 12164 standard were not opened, so the official range is not settled here.'
- Strength by temper covers O60, H02 and H04 round rod (Fisk) and H02 bar 12.7 mm and under (Aviva). No hard or soft value for bar was read. The Smith range of 338 to 469 MPa tensile and 124 to 310 MPa yield gives no temper for each value, so it is not used. The National Bronze mechanical table did not extract cleanly from the page and is not used.
- 'Hardness: only one range (H02 bar, HRB 60 to 80, from Aviva). No hardness for O60 or H04 was read. The benchmark name hardness_rockwell_b is not in the property canon.'
- Machinability is a supplier's relative index with C36000 set at 100, not a measured property. The benchmark name machinability_rating is not in the property canon.
- Electrical conductivity uses the snake_case name electrical_conductivity, which is not in the property canon. The Fisk metric value for the same row (0.15 MS·cm) does not convert, so only the 26 %IACS value is used.
- 'Dezincification and season cracking: no depth, rate, threshold stress or time to failure for C36000 was in a page we could read. The Rimkus case study on failed C36000 plumbing fittings returned a blocked page to the fetcher and is not used.'
- No atmospheric corrosion rate for C36000 was found in the pages read. The Copper Development Association page returned a forbidden page to the fetcher, so its alloy data sheet was not used.
- 'No space-environment data for brass were read: no outgassing, atomic-oxygen, cold-welding or radiation result for C36000. The tags.environments list is empty for this reason. The habitats-and-suits application tag reflects plumbing fittings and fluid connectors only, which is our mapping; no source names a space use.'
- Thermal conductivity and coefficient of thermal expansion from Fisk are not stated with a temper; the page gives one value for the alloy.
- 'No CAS number: brass is identified by its UNS number, C36000, and no CAS source was read.'
- Specific heat, Poisson's ratio and cast-form densities were not searched.
- Lead is a recognised health hazard in the sources, but no lead-free brass value was taken from a page other than Aviva's own Model 3 comparison, which is a vendor's claim.
- No media (images) were added to this profile; no image was fetched or checked in this run.
- 'Recycling: no brass-specific recycling share was found; the copper summary''s statement that brass and wire-rod mills took about 80 % of scrap-recovered copper is the closest figure.'
- 'Designations: JIS C3604 and ASTM B453 are not printed by any page read in this run (Fisk, National Bronze, Aviva, Smith, Wieland, the Aalco product guide, Concast, Wikipedia, Metals Supermarkets). copper.org and muellerbrass.com returned 403 and olinbrass.com does not resolve, so those pages may still hold these codes.'
- 'Designations: BS CZ121 is not listed for C36000. The Aalco product guide prints CZ121Pb3 for CuZn39Pb3 (CW614N), a different alloy, and gives CZ124 as the nearest old BS equivalent of CuZn36Pb3; CZ124 is listed with note nearest equivalent.'
- 'Designations: no ISO code, no Alloy 360 name and no product form for ASTM B16 is printed by any page read in this run.'
sources:
fisk-ma36b:
title: 'Fisk Alloy, C36000 Free-Cutting Brass (CuZn36Pb3), product MA36B: physical properties, pretempered round wire and round rod tables, composition'
url: https://fiskalloy.com/product/ma36b/
kind: datasheet
license: Supplier web page (cited, not reproduced)
aviva-c36000:
title: 'Aviva Metals, C36000 free-machining brass product page: chemical composition, Model 3 comparison table, dezincification note'
url: https://avivametals.com/products/c36000-free-machining-brass-free-cutting-brass
kind: datasheet
license: Supplier web page (cited, not reproduced)
smith-c36000:
title: Smiths Metal Centres, C36000 Free-Machining Brass product datasheet (2023)
url: https://www.smithmetal.com/pdf/brass/c36000.pdf
year: 2023
kind: datasheet
license: Supplier datasheet (cited, not reproduced)
natbronze-c36000:
title: 'National Bronze and Metals, C36000 Free Cutting Brass Bar: composition, nominal composition, applications'
url: https://nationalbronze.com/C36000_Free_Cutting_Brass.php
kind: datasheet
license: Supplier web page (cited, not reproduced)
wiki-brass:
title: 'Brass (Wikipedia): lead content, dezincification, season cracking, alloy composition table'
url: https://en.wikipedia.org/wiki/Brass
year: 2026
kind: web
license: CC BY-SA 4.0 (cited, not reproduced)
hgh-scc:
title: 'The Hendrix Group, Material Property Data: copper and copper alloys, brasses, stress corrosion cracking'
url: https://hghouston.com/archive/material-property-data/copper-and-copper-alloys/brasses/sc-cracking
kind: web
license: Technical archive page (cited, not reproduced)
atsdr-lead:
title: 'ATSDR ToxFAQs: Lead (Agency for Toxic Substances and Disease Registry, U.S. CDC)'
url: https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=93&toxid=22
kind: report
license: U.S. government public domain (cited, not reproduced)
usgs-mcs2026-copper:
title: 'Mineral Commodity Summaries 2026: Copper'
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-mcs2026-zinc:
title: 'Mineral Commodity Summaries 2026: Zinc'
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-mcs2026-lead:
title: 'Mineral Commodity Summaries 2026: Lead'
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lead.pdf
year: 2026
kind: report
license: public domain (USGS)
wieland-brass-alloys:
title: 'Wieland: brass alloys, machining brass table (EN designation, EN No., ASTM UNS-No., JIS-No.)'
url: https://www.wieland.com/products/brass-alloys
kind: datasheet
license: Manufacturer web page (cited, not reproduced)
aalco-copper-brass-bronze:
title: 'Aalco Product Guide: copper, brass and bronze, wrought copper-zinc-lead alloys and BS to EN conversion table'
url: https://www.aalco.co.uk/literature/files/aalco-copper-brass-bronze.pdf
kind: datasheet
license: Stockist product guide (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-24'
review:
status: draft
method: assistant
checked_values: 23
unreachable: 10
caveats: 6
note: 'Values were read by an AI assistant on 2026-10-24 from the pages and PDFs named in each entry. Unreachable to the fetcher (bot, challenge or forbidden pages): MakeItFrom (three C36000 pages), copper.org alloy 360 page, PubChem lead, NIOSH lead, OSHA lead, ATSDR lead profile, Rimkus C36000 case study, and Materials Plus. Caveats: strength values are minimum values from one supplier''s rod table and one supplier''s bar comparison, not from the ASTM B16 text; the lead range differs between sources (2.5 to 3.0 and 2.5 to 3.7 wt%); the hardness and machinability names are not in the property canon; dezincification and season-cracking statements are qualitative; no space-environment data; the Fisk elastic modulus is printed with a units error and was not recorded.'
story:
risk_groups:
- title: For people
lead: The lead in C36000 is the main health concern in these sources. They give health effects of lead but no exposure limit for brass dust.
level: 2
verdict: Leaded alloy
points:
- label: Lead in the alloy
line: C36000 has 2.5 to 3.0 % lead (Aviva and Fisk limits; Wikipedia gives 2.5 to 3.7 % for C360). The ATSDR says lead can affect almost every organ and system, and the U.S. Department of Health and Human Services considers lead and lead compounds reasonably anticipated to be human carcinogens.
- label: Plumbing
line: California defines lead-free brass as containing no more than 0.25 % lead (AB 1953), down from 4.0 % on 1 January 2010 (Wikipedia). Aviva says the U.S. plumbing industry replaced C36000 with lead-free alternatives from January 2010.
- title: If it fails
lead: The failure routes in these sources are chemical (water and ammonia) and, for the hard temper, mechanical.
points:
- label: Dezincification
line: In water with chlorides, high temperature or soft quality, zinc leaves the alloy and a weak copper layer remains. Aviva says this can create catastrophic failures.
- label: Season cracking
line: Cold work leaves stress, and in an ammonia or amine atmosphere the alloy can crack. The Hendrix Group describes the crack pattern for simple alpha brass, not for C36000.
- label: Hard temper
line: The H04 hard temper reaches 480 MPa minimum tensile strength, but its elongation is only 4 % minimum, so there is little room for bending.
- title: Handling and storage
points:
- label: Pick the temper
line: Annealed O60 round rod has 330 MPa minimum tensile and 15 % elongation. Half-hard H02 has 390 MPa and 7 %. Hard H04 has 480 MPa and 4 %.
- label: Stress relief
line: Stress-relieve parts after cold work, as the Hendrix Group advises, and keep them out of ammonia and amine atmospheres.
why: Free-cutting brass is chosen for ease of machining. National Bronze says its two-phase structure forms broken chips instead of long coils, and that the lead content adds internal lubrication against the cutting tool. The alloy is rated 100 on the supplier machinability scale. It conducts electricity at 26 %IACS and heat at 116 W/(m·K) at 20 °C (Fisk MA36B). Its density is 8.5 g/cm3. The lead content is the reason it falls outside California's lead-free plumbing rule, and it is the main health concern in these sources.
uses:
- where: Screw-machine parts and fasteners
line: National Bronze lists screw machine products, valve components, fasteners, fittings, hardware, fluid connectors and automotive sensor housings as C36000 applications. Smith lists machine screw parts, high-volume parts, plumbing components and fluid connectors.
- where: Fittings and fluid connectors
line: Smith says C36000 offers good corrosion resistance and is readily brazed or soldered, and lists fittings and adaptors and fluid connectors among its applications. These are terrestrial uses; no source names a space system.
can_do:
- label: Cut fast
value: machinability rated 100
line: Aviva and National Bronze give C36000 a machinability rating of 100, and National Bronze calls it the standard against which other metals are measured. The scale is the supplier's, not a measured value.
- label: Carry current
value: 26 %IACS
line: Electrical conductivity is 26 %IACS when annealed (Fisk) and 26 % in the half-hard H02 bar (Aviva). Fisk prints an electrical resistivity of 6.63 µΩ·cm at 20 °C when annealed.
- label: Carry heat
value: 116 W/(m·K)
benchmark: thermal_conductivity
line: Thermal conductivity is 116 W/(m·K) at 20 °C (Fisk MA36B, metric column).
- label: Strength by temper
value: 330 to 480 MPa minimum tensile
line: Round rod minimum tensile strength is 330 MPa annealed, 390 MPa half hard and 480 MPa hard (Fisk). Aviva gives 395 MPa minimum for half-hard bar 12.7 mm and under.
- label: Weight
value: 8.5 g/cm3
benchmark: density
line: Density is 8.5 g/cm3 (Fisk MA36B, metric column).
- label: Melting
value: 954 to 1049 °C
line: The solidus is 954 °C and the liquidus is 1049 °C (Fisk MA36B, metric column).
- label: Expansion
value: 20.5 ppm/K
benchmark: cte
line: The coefficient of thermal expansion is 20.5 ppm/K over 20 to 300 °C (Fisk MA36B, printed as per °C).
compare: The [copper profile](/profiles/copper/) covers the pure metal, and it is the natural comparison for conductivity and density. Within the Aviva comparison, its lead-free Model 3 alloy has a higher minimum yield strength and a higher electrical conductivity than C36000 half-hard bar 12.7 mm and under (170 MPa and 26 %IACS for C36000). It has a lower minimum tensile strength and a lower machinability rating (395 MPa and 100 for C36000). These are Aviva's own figures for its own alloy, so they are a vendor's comparison and not an independent test.
compare_rows:
- label: Density
benchmark: density
- label: Thermal conductivity
benchmark: thermal_conductivity
- label: Thermal expansion
benchmark: cte
handling:
- 'Specify the temper: strength runs from 330 MPa minimum tensile in annealed O60 round rod to 480 MPa in hard H04 round rod.'
- Stress-relieve after cold work (pressing, spinning, drawing, bending), and keep parts out of ammonia and amine atmospheres.
- The alloy contains lead, so machining chips and dust are lead sources; the ATSDR advice to avoid lead exposure applies to them (this is our inference from the advice, not a statement in the source).
good_for:
- Machined parts in volume, where machinability rated 100 is the main selection criterion.
- Fittings and connectors that need 330 to 480 MPa minimum tensile strength, chosen by temper.
- 'Brazed or soldered assemblies: Smith rates the alloy as readily brazed or soldered.'
watch_out:
- Lead at 2.5 to 3.0 % puts the alloy outside California's 0.25 % limit for lead-free plumbing brass.
- Dezincification in water and season cracking in ammonia, both caused by the zinc content and by stress.
- Hard H04 round rod stretches only 4 % minimum, which limits forming.
- The shear modulus of 37 GPa is a typical value with no temper stated, and no elastic modulus is recorded (see gaps).
verdict: Free-cutting brass C36000 is the machinability reference among brasses, rated 100 on the supplier scale. It conducts at 26 %IACS and gives 330 to 480 MPa minimum tensile strength across the O60 to H04 tempers. Its 2.5 to 3.0 % lead rules it out of California's lead-free plumbing brass, and its zinc content invites dezincification in water and season cracking in ammonia. No corrosion rate, no space-environment result and no elastic modulus were found in the pages read.
recipe:
line: Free-cutting brass is a copper-zinc alloy with 2.5 to 3.0 % lead. National Bronze says its two-phase structure forms broken chips. Wikipedia says lead is often added at about 2 % to improve machinability, and that it forms globules at the grain boundaries as the casting cools.
parts:
- name: Copper
symbol: Cu
share: 60.0 to 63.0 wt%
role: Main metal and matrix of the alloy (limits from Aviva, Fisk and Smith).
- name: Zinc
symbol: Zn
share: remainder (nominal 35.4 wt% on the National Bronze page)
role: The alloying element that makes the brass. Above 15 % zinc, dezincification risk rises (Aviva).
- name: Lead
symbol: Pb
share: '2.5 to 3.0 wt% (Wikipedia C360 row: 2.5 to 3.7 wt%)'
role: Added for machinability; National Bronze says the lead content adds internal lubrication against the cutting tool.
- name: Iron
symbol: Fe
share: 0.35 wt% maximum
role: Impurity limit printed on the Aviva, Fisk and National Bronze pages.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.