Phosphor bronze C52100 (CuSn8) C521
Cu-Sn-P wrought alloy, UNS C52100 (CuSn8): copper remainder, tin 7.00 to 9.00 %, phosphorus 0.03 to 0.35 %
Also known as UNS C52100, EN name CW453K, EN name CuSn8, EN name CuSn8P, JIS C5210, BS PB104 · 2 more
Phosphor bronze C52100 (UNS C52100, CDA C521, EN CW453K, name CuSn8) is a wrought copper alloy with 7.00 to 9.00 % tin and 0.03 to 0.35 % phosphorus.
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.
Carry springs
725 to 820 MPa tensile
Take the density
8.79 g/cm3
Conduct electricity
13 %IACS
Melt
882 to 1027 °C
Recipe, share of the weight
- Cu not statedCopper
- Sn not statedTin
- P not statedPhosphorus
- Pb not statedLead
- Zn not statedZinc
- Fe not statedIron
Best for
Springs and connectors: the H08 spring temper has 725 to 820 MPa tensile strength and 690 MPa minimum yield (Aurubis), and the alloy solders and brazes excellently
Weakest at
Dust and fume when cut, ground or welded (Fisk SDS); the only seawater corrosion rate read is an unnamed-test manufacturer claim (jtcopper)
Risk at a glance
- People Low. Dust and fume, not solid metal
- If it fails Moderate. Fatigue under reversed bending
- Corrosion Low. The jtcopper page states a seawater corrosion rate below 0.015 mm/year for C52100.
Quick facts: C521
| Property | Value | Basis |
|---|---|---|
| Density | 8.79 g/cm³ | 1 sourced value |
| Yield strength | 350 to 725 MPa | 4 sourced values across conditions |
| Tensile strength | 475 to 840 MPa | 5 sourced values across conditions |
| Young's modulus | 115 GPa | 1 sourced value |
| Thermal conductivity | 67 W/(m·K) | 1 sourced value |
| Thermal expansion (CTE) | 17.4 ppm/K | 1 sourced value |
| Melting point | 882 to 1,027 °C | 1 sourced value |
| Specific heat | 377 J/(kg·K) | 1 sourced value |
What is the density of Phosphor bronze C52100 (CuSn8)?
Phosphor bronze C52100 (CuSn8) has a density of 8.79 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Phosphor bronze C52100 (CuSn8)?
Phosphor bronze C52100 (CuSn8) has a thermal conductivity of 67 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 Phosphor bronze C52100 (CuSn8)?
Phosphor bronze C52100 (CuSn8) has a coefficient of thermal expansion of 17.4 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Phosphor bronze C52100 (CuSn8)?
Phosphor bronze C52100 (CuSn8) has a melting point of 882 to 1,027 °C. The source and test conditions are listed in the properties table on this page.
What is the yield strength of Phosphor bronze C52100 (CuSn8)?
Phosphor bronze C52100 (CuSn8) has a yield strength of 350 to 725 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 Phosphor bronze C52100 (CuSn8)?
Phosphor bronze C52100 (CuSn8) is also written as UNS C52100, EN name CW453K, EN name CuSn8, EN name CuSn8P, JIS C5210, BS PB104. Each code is printed in the source listed beside it in the designations table.
What is Phosphor bronze C52100 (CuSn8) used for?
Uses recorded in the sources include Connectors and relay springs; Springs, slide bearings and bushings; Retaining clamps.
Why it exists
Phosphor bronze C52100 is a copper alloy with about 8 % tin and 0.2 % phosphorus. Aurubis calls it the highest alloyed phosphor bronze in its family, and the tin gives it high strength with still adequate conductivity. The Aurubis table gives 725 to 820 MPa tensile for the H08 spring temper, and Concast gives 585 MPa minimum for H04 hard. The alloy is used for springs, connectors, relays and slide bearings.
Where it's used
Connectors and relays
Aurubis lists connectors, frame connectors, relays and conductor springs among the typical uses of C52100.
Springs and slide bearings
Aurubis lists spring rings, slide bearings and bushings. Wikipedia lists springs, bolts, bushings and bearings among phosphor bronze uses.
Retaining clamps
Aurubis lists retaining clamps among the typical uses of C52100.
Recipe
Cu-Sn-P wrought alloy, UNS C52100 (CuSn8): copper remainder, tin 7.00 to 9.00 %, phosphorus 0.03 to 0.35 %; lead 0.05 max, zinc 0.20 max, iron 0.10 max (wt %)
C52100 is a copper-tin-phosphorus alloy: copper is the matrix, and tin gives most of the strength and the corrosion resistance. Phosphorus is a trace addition that Wikipedia says raises wear resistance and stiffness. Lead, zinc and iron are impurity limits, and the wrought bar, rod, wire and strip are made by cold working and annealing.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Copper Cu | not stated | The matrix. Concast and the ASTM B139 composition table give copper as the remainder. |
| Tin Sn | not stated | Gives most of the strength and corrosion resistance (Concast composition table, Wikipedia). |
| Phosphorus P | not stated | A trace addition that raises wear resistance and stiffness (Wikipedia). |
| Lead Pb | not stated | Impurity limit. |
| Zinc Zn | not stated | Impurity limit. |
| Iron Fe | not stated | Impurity limit. |
Weight shares are as printed in the sources.
What it can do
Carry springs
725 to 820 MPa tensile
measured
The H08 spring temper has a tensile range of 725 to 820 MPa, with a minimum yield of 690 MPa (Aurubis).
Take the density
8.79 g/cm3
measured
The Aurubis datasheet gives a density of 8.79 g/cm3 at 20 °C.
Conduct electricity
13 %IACS
measured
The Concast page gives an electrical conductivity of 13 %IACS at 68 °F.
Melt
882 to 1027 °C
measured
The solidus is 882 °C and the liquidus is 1027 °C in the Concast table. The Aurubis datasheet gives a single melting point of 1040 °C.
How it compares
Among the phosphor bronzes, C52100 is the highest-tin member (7.00 to 9.00 % tin in the ASTM B139 limits). Its strength in the spring tempers is the highest of the tin-bronze grades read here, and its electrical conductivity is 13 %IACS. The lower-tin C51000 grade has its own profile, bronze-c510, for direct comparison.
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 | C521 | Cu | C360 | C954 | C630 | BeCu | C510 | C260 | Cu-Ag | CuCrZr | CuNi 70/30 | C21000 | CW614N | C75200 | C655 | Cu-Te | Sn/Cu |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | |||||||||||||||||
| Solidus and liquidus, phosphor bronze C52100 | 882 to 1027 °C2 | 1083 °C | 954 °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 | 971 to 1027 °C | 1080 °C | 231.9 °C |
| Thermal conductivity at 20 °C, phosphor bronze C52100 | 67 W/(m·K)4 | 391 W/(m·K) | 116 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) | 36.3 W/(m.K) | 355 W/(m·K) | 66.6 W/(m·K) |
| Specific heat capacity at 20 °C, phosphor bronze C52100 | 0.377 kJ/(kg·K)6 | 0.394 kJ/(kg·K) | no data | 419 J/(kg·K) | 452 J/(kg·K) | no data | 0.38 J/(g·°C) | 377.1 J/(kg·K) | no data | 0.383 kJ/(kg·K) | 377 J/(kg·K) | 0.38 J/(g·K) | 380 J/(kg·K) | 380 J/(kg·K) | 376.8 J/(kg.K) | 385.5 J/(kg·K) | no data |
| Physical and electrical | |||||||||||||||||
| Density, phosphor bronze C52100 | 8.79 g/cm³1 | 8.9 g/cm³ | 8.5 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 | 8.53 g/cm³ | 8.94 g/cm³ | 7.28 g/cm³ |
| Electrical conductivity, phosphor bronze C52100 | 13 %IACS3 | 58 MS/m | 26 %IACS | 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 | 7 %IACS | 93 %IACS | 58 MS/m |
| Other measurements | |||||||||||||||||
| Coefficient of linear thermal expansion, 20 to 300 °C | 17.4 µm/(m·°C)5 | 17.6 ppm/K | 20.5 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 | 18 um/(m.°C) | 16.5 ppm/K | 22 ppm/K |
| Modulus of elasticity, phosphor bronze C52100 | 115 GPa7 | 117 GPa | no data | 1.07×10^5 MPa | 117 GPa | 131 GPa | 110 GPa | 1.1×10^5 MPa | no data | 117 GPa | no data | 117 GPa | 97 GPa | 135 GPa | 1.03×10^5 MPa | 1.17×10^5 MPa | 50 GPa |
| Tensile strength, H02 temper, range | 475 to 580 MPa8 | 179 to 262 MPa | > 330 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 | 538 MPa | > 260 MPa | no data |
| Yield strength Rp0.2, H02 temper, minimum | > 350 MPa9 | 69 MPa | > 130 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 | 310 MPa | > 205 MPa | no data |
| Elongation, H02 temper, minimum | > 25 %10 | 35 % | > 15 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | 17 % | > 8 % | no data |
| Tensile strength, H04 hard temper, minimum | > 585 MPa11 | 179 to 262 MPa | > 330 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 | 538 MPa | > 260 MPa | no data |
| Elongation, H04 hard temper, minimum | > 12 %12 | 35 % | > 15 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | 17 % | > 8 % | no data |
| Tensile strength, H08 spring temper, range | 725 to 820 MPa13 | 179 to 262 MPa | > 330 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 | 538 MPa | > 260 MPa | no data |
| Yield strength Rp0.2, H08 spring temper, minimum | > 690 MPa14 | 69 MPa | > 130 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 | 310 MPa | > 205 MPa | no data |
| Elongation, H08 spring temper, minimum | > 3 %15 | 35 % | > 15 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | 17 % | > 8 % | no data |
| Tensile strength, H10 extra spring temper, range | 760 to 840 MPa16 | 179 to 262 MPa | > 330 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 | 538 MPa | > 260 MPa | no data |
| Yield strength Rp0.2, H10 extra spring temper, minimum | > 725 MPa17 | 69 MPa | > 130 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 | 310 MPa | > 205 MPa | no data |
| Ultimate tensile strength, hard temper (France et al. 1969 data) | 690 MPa18 | 179 to 262 MPa | > 330 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 | 538 MPa | > 260 MPa | no data |
| Yield strength, hard temper (France et al. 1969 data) | 510 MPa19 | 69 MPa | > 130 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 | 310 MPa | > 205 MPa | no data |
| Elongation, hard temper (France et al. 1969 data) | 10 %20 | 35 % | > 15 % | > 12 % | > 10 % | 20 to 75 % | > 13 % | 62 % | > 37 % | > 10 % | 30 to 45 % | 45 % | > 20 % | 40 % | 17 % | > 8 % | no data |
Why choose it, and why not
Good for
- Springs and connectors: the H08 spring temper gives 725 to 820 MPa tensile strength, with 690 MPa minimum yield (Aurubis).
- Slide bearings and bushings: Aurubis rates the alloy for good sliding properties and wear resistance.
- Solderable and brazeable parts: Aurubis rates soldering and brazing as excellent.
Watch out for
- Dust and fume when cut, ground or welded, per the Fisk SDS.
- Spring tempers rest on one manufacturer datasheet, so confirm the temper on a mill certificate.
- The seawater corrosion rate below 0.015 mm/year is a manufacturer claim without a named test.
- Melting, thermal conductivity and modulus figures differ between the Concast and Aurubis sources.
Phosphor bronze C52100 is the highest-tin member of the phosphor bronze family, with 7.00 to 9.00 % tin. Its strength depends strongly on temper, and the H08 spring temper gives 725 to 820 MPa tensile strength. The alloy solders and brazes well, and dust from machining is the main hazard. This profile lacks a verified seawater test, a confirmed EN code and an annealing range.
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 | C52100 |
| EN name | CW453K, CuSn8, CuSn8P |
| JIS | C5210 |
| BS | PB104 |
| CDA | C521 |
| ASTM | B139 (rod and bar) |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, phosphor bronze C52100 | Value printed in a manufacturer technical datasheet | grade C52100 (CuSn8)temperature 20 °Cunit in source 0.318 lb/in3 at 20 °C | — |
| 2 | Solidus and liquidus, phosphor bronze C52100 | Solidus and liquidus printed in the physical properties table of a manufacturer page; value is the solidus (low) and the liquidus (high) | grade C52100unit in source solidus 1620 °F; liquidus 1880 °Fpressure not stated | The Aurubis datasheet prints a single melting point of 1040 °C (1904 °F) for the same alloy. The Concast range is used here and the conflict is listed in gaps. |
| 3 | Electrical conductivity, phosphor bronze C52100 | Value printed in the physical properties table of a manufacturer page | grade C52100temperature 68 °F (20 °C)unit in source 13% IACS at 68 °F | — |
| 4 | Thermal conductivity at 20 °C, phosphor bronze C52100 | Value printed in a manufacturer technical datasheet | temperature 20 °Cunit in source 39 Btu/ft h °F | The Concast table prints 36 Btu/sq ft/ft hr/°F (62.3 W/m) for the same alloy. The Aurubis value is used and the conflict is listed in gaps. |
| 5 | Coefficient of linear thermal expansion, 20 to 300 °C | Value printed in a manufacturer page, physical properties table | temperature range 20 to 300 °Cunit in source 10.1 ·10-6 per °F (68-572 °F) | — |
| 6 | Specific heat capacity at 20 °C, phosphor bronze C52100 | Value printed in a manufacturer technical datasheet | temperature 20 °Cunit in source 0.09 Btu/lb °F | — |
| 7 | Modulus of elasticity, phosphor bronze C52100 | Value printed in a manufacturer technical datasheet | temperature 20 °Cunit in source 16.7 x1000 ksi | The Concast page prints 110310 MPa for the modulus of elasticity in tension. The Aurubis value is used and the difference is listed in gaps. |
| 8 | Tensile strength, H02 temper, range | Range printed in a manufacturer mechanical properties table | temper H02 (1/2H)unit in source 69 to 84 ksi | — |
| 9 | Yield strength Rp0.2, H02 temper, minimum | Minimum value printed in a manufacturer mechanical properties table | temper H02 (1/2H)unit in source 51 ksi | — |
| 10 | Elongation, H02 temper, minimum | Minimum value printed in a manufacturer mechanical properties table | temper H02 (1/2H)gauge length 2 inch | — |
| 11 | Tensile strength, H04 hard temper, minimum | Minimum value printed in a manufacturer mechanical properties table | temper H04 hardsize 1/4 to 1/2 inch round and hexagonalunit in source 85 ksistandard ASTM B139/B139M | — |
| 12 | Elongation, H04 hard temper, minimum | Minimum value printed in a manufacturer mechanical properties table | temper H04 hardsize 1/4 to 1/2 inch round and hexagonalbasis 4 times diameter | — |
| 13 | Tensile strength, H08 spring temper, range | Range printed in a manufacturer mechanical properties table | temper H08 (SH) springunit in source 105 to 119 ksi | — |
| 14 | Yield strength Rp0.2, H08 spring temper, minimum | Minimum value printed in a manufacturer mechanical properties table | temper H08 (SH) springunit in source 100 ksi | — |
| 15 | Elongation, H08 spring temper, minimum | Minimum value printed in a manufacturer mechanical properties table | temper H08 (SH) springgauge length 2 inch | — |
| 16 | Tensile strength, H10 extra spring temper, range | Range printed in a manufacturer mechanical properties table | temper H10 (ES) extra springunit in source 110 to 122 ksi | — |
| 17 | Yield strength Rp0.2, H10 extra spring temper, minimum | Minimum value printed in a manufacturer mechanical properties table | temper H10 (ES) extra springunit in source 105 ksi | — |
| 18 | Ultimate tensile strength, hard temper (France et al. 1969 data) | Value in the data file of a University of Waterloo materials page, which cites W.D. France et al., ASTM Journal of Materials, 1969; the source notes the data were digitised from plots and may contain errors | temper hardform stripunit in source 100 ksi | — |
| 19 | Yield strength, hard temper (France et al. 1969 data) | Value in the data file of a University of Waterloo materials page; digitised from plots | temper hardform strip | — |
| 20 | Elongation, hard temper (France et al. 1969 data) | Value in the data file of a University of Waterloo materials page; digitised from plots | temper hardgauge length 2 inch | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Seawater and weak acids, manufacturer claim | low | The jtcopper page states a seawater corrosion rate below 0.015 mm/year for C52100.1 |
| Air and general service, qualitative | low | Aurubis rates C52100 as having better corrosion resistance than the other alloys in its family and good sliding properties, with no numeric rate.2 |
| Alloy chemistry, tin content | low | Tin is the element that gives phosphor bronze its corrosion resistance and strength.3 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Seawater and weak acids, manufacturer claim | The page gives this rate in its key features and core advantages sections but names no test method or exposure time. It is recorded as a claim, not a test result. | basis manufacturer statement, no test standard namedexposure seawater, duration not stated |
| 2 | Air and general service, qualitative | The datasheet text says the alloy has better corrosion resistance, and it names no exposure or test. No corrosion rate in mm/year or mpy was printed on any page read in this run. | basis qualitative statement from a manufacturer datasheetexposure not stated |
| 3 | Alloy chemistry, tin content | Wikipedia says tin increases the corrosion resistance and strength of the alloy. The article gives no corrosion data and describes phosphor bronze in general, not C52100 in particular. | basis general description, no test data |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The opened sources give a hazard for dust and fume from the alloy, not for the solid metal.
- Solid alloy
- The Fisk SDS classifies the solid alloy as Not Classified under GHS-US, with no labelling. Hazards come from the dust, fume and powder made when it is cut, ground or welded.
- Tin and phosphorus in dust
- The same SDS says tin dust and fume can cause stannosis after chronic exposure and that tin has been shown to increase sarcoma incidence in animal tests. It also says long-term phosphorus exposure may affect the kidney and liver.
If it fails
The failure routes in the sources are fatigue in hard temper strip and use above the printed service limit.
- Fatigue
- In the digitised 1969 data, a sample at 329 MPa stress amplitude failed at 830,340 reversals, and samples at 187 and 194 MPa reached 200,000,000 reversals without failure.
- Service limit
- The jtcopper page prints a maximum service temperature of 200 °C. It gives no test basis for that figure.
Handling and storage
- Specify the temper
- H02 has 475 to 580 MPa tensile strength, H08 spring has 725 to 820 MPa, and H10 extra spring has 760 to 840 MPa. Choose the temper before the strength is quoted.
- Dust
- Control dust, fume and sparks when cutting, grinding or welding.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Fatigue under reversed bendingmoderate severity | Cyclic bending of hard temper strip at stress amplitudes of about 187 to 329 MPaIn the digitised 1969 data, the sample at 329 MPa failed at 830,340 reversals, and the samples at 187 and 194 MPa reached 200,000,000 reversals without failure. |
| Exceeding the maximum service temperaturemoderate severity | Service above 200 °CThe jtcopper page prints a maximum service temperature of 200 °C. Above it the spring temper and its strength are not expected to hold, but the page gives no test basis for the limit. |
Handling and storage
- Specify the temper, since H02, H04, H08 and H10 have very different strengths, from 475 to 580 MPa for H02 to 725 to 820 MPa for H08.
- H04 hard has a minimum tensile strength of 585 MPa in 1/4 to 1/2 inch round and hexagonal sizes.
- Control dust, fume and sparks when cutting, grinding or welding, since the SDS warns of irritation and a combustible dust hazard.
Supply and geography
How common the raw materials are and where they come from.
Copper (remainder of the alloy)
- Top producers (2025)
- Chile 23%, Congo (Kinshasa) 13.9%, Peru 11.7%, China 7.8%, Russia 5.7%
- Critical mineral lists
- U.S. Final 2025 List of Critical Minerals (copper added, 90 FR 50494): listed
- Recycling
- USGS: old scrap provided an estimated 160,000 tons of copper in 2025, and about 760,000 tons was recovered from new scrap; scrap contributed about 30 % of U.S. copper supply.
- Substitutes
- USGS: aluminum substitutes for copper in electrical equipment and power cable, and optical fiber substitutes for copper in telecommunications applications.
Tin (7.00 to 9.00 % of the alloy)
- Top producers (2025)
- China 24.5%, Indonesia 21%, Peru 11.4%, Brazil 9.7%, Congo (Kinshasa) 9.3%
- Recycling
- USGS: about 17,000 tons of tin from old and new scrap was estimated to have been recycled in 2025.
- Substitutes
- USGS: aluminum, glass, paper, plastic or tin-free steel substitute for tin in cans and containers; epoxy resins substitute for tin in solder.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
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spore: profile
id: phosphor-bronze-c521
spore_version: 0.2
family: copper-alloys
name: Phosphor bronze C52100 (CuSn8)
abbreviation: C521
role: highest-tin wrought phosphor bronze for springs, connectors and slide bearings
category: metals
type: copper-alloys
summary: |
Phosphor bronze C52100 (UNS C52100, CDA C521, EN CW453K, name CuSn8) is a wrought copper alloy with 7.00 to 9.00 % tin and 0.03 to 0.35 % phosphorus. Aurubis calls it the highest alloyed phosphor bronze in its family. Its density is 8.79 g/cm3 and its annealed electrical conductivity is 13 %IACS. The spring temper H08 has a tensile strength of 725 to 820 MPa and a minimum yield strength of 690 MPa, and H10 reaches 760 to 840 MPa. It is sold for springs, connectors, relays and slide bearings.
best_for: 'Springs and connectors: the H08 spring temper has 725 to 820 MPa tensile strength and 690 MPa minimum yield (Aurubis), and the alloy solders and brazes excellently'
weakest_at: Dust and fume when cut, ground or welded (Fisk SDS); the only seawater corrosion rate read is an unnamed-test manufacturer claim (jtcopper)
identity:
formula: 'Cu-Sn-P wrought alloy, UNS C52100 (CuSn8): copper remainder, tin 7.00 to 9.00 %, phosphorus 0.03 to 0.35 %; lead 0.05 max, zinc 0.20 max, iron 0.10 max (wt %)'
source: concast-c52100
where: Chemical composition table, ASTM B139/B139M-12(2024), C52100 row (concast.com); the jtcopper page prints the same tin, phosphorus, iron, lead and zinc limits
designations:
- system: UNS
code: C52100
source: aurubis-c52100
where: 'Header, Comparable standards line: UNS C52100'
- system: CDA
code: C521
source: concast-c52100
where: Similar-specification table, C52100 row, CDA column
- system: EN name
code: CW453K
source: aurubis-c52100
where: 'Header, Comparable standards line: EN CW453K'
- system: EN name
code: CuSn8
source: aurubis-c52100
where: Title line, C52100 (CuSn8)
- system: EN name
code: CuSn8P
source: concast-c52100
where: Opening sentence, C521 also designated as CuSn8P
- system: BS
code: PB104
source: concast-c52100
where: Opening sentence, C521 also designated as PB104
- system: JIS
code: C5210
source: jtcopper-c52100
where: Other designations line, JIS C5210
- system: ASTM
code: B139
note: rod and bar
source: concast-c52100
where: Similar-specification table, C52100 row, ASTM column (ASTM B139/B139M)
tags:
environments: []
stresses: []
applications:
- electronics-and-chips
- mechanisms
- structures
properties:
- benchmark: density
label: Density, phosphor bronze C52100
value: 8.79
unit: g/cm3
scope: material
conditions:
grade: C52100 (CuSn8)
temperature: 20 °C
unit_in_source: 0.318 lb/in3 at 20 °C
method: Value printed in a manufacturer technical datasheet
status: ground
source: aurubis-c52100
where: Physical properties table, row Density, metric value
- benchmark: melting_point
label: Solidus and liquidus, phosphor bronze C52100
value: 882
value_high: 1027
bound: range
unit: °C
scope: material
conditions:
grade: C52100
unit_in_source: solidus 1620 °F; liquidus 1880 °F
pressure: not stated
method: Solidus and liquidus printed in the physical properties table of a manufacturer page; value is the solidus (low) and the liquidus (high)
status: ground
note: The Aurubis datasheet prints a single melting point of 1040 °C (1904 °F) for the same alloy. The Concast range is used here and the conflict is listed in gaps.
source: concast-c52100
where: Physical properties table, rows Melting range liquidus and solidus
- benchmark: electrical_conductivity
label: Electrical conductivity, phosphor bronze C52100
value: 13
unit: '%IACS'
scope: material
conditions:
grade: C52100
temperature: 68 °F (20 °C)
unit_in_source: 13% IACS at 68 °F
method: Value printed in the physical properties table of a manufacturer page
status: ground
source: concast-c52100
where: Physical properties table, row Electrical conductivity
- benchmark: thermal_conductivity
label: Thermal conductivity at 20 °C, phosphor bronze C52100
value: 67
unit: W/(m·K)
scope: material
conditions:
temperature: 20 °C
unit_in_source: 39 Btu/ft h °F
method: Value printed in a manufacturer technical datasheet
status: ground
note: The Concast table prints 36 Btu/sq ft/ft hr/°F (62.3 W/m) for the same alloy. The Aurubis value is used and the conflict is listed in gaps.
source: aurubis-c52100
where: Physical properties table, row Thermal cond. at 20 °C, metric value
- benchmark: cte
label: Coefficient of linear thermal expansion, 20 to 300 °C
value: 17.4
unit: µm/(m·°C)
scope: material
conditions:
temperature_range: 20 to 300 °C
unit_in_source: 10.1 ·10-6 per °F (68-572 °F)
method: Value printed in a manufacturer page, physical properties table
status: ground
source: concast-c52100
where: Physical properties table, row CTE, metric value
- benchmark: specific_heat
label: Specific heat capacity at 20 °C, phosphor bronze C52100
value: 0.377
unit: kJ/(kg·K)
scope: material
conditions:
temperature: 20 °C
unit_in_source: 0.09 Btu/lb °F
method: Value printed in a manufacturer technical datasheet
status: ground
source: aurubis-c52100
where: Physical properties table, row Specific heat capacity at 20 °C, metric value
- benchmark: elastic_modulus
label: Modulus of elasticity, phosphor bronze C52100
value: 115
unit: GPa
scope: material
conditions:
temperature: 20 °C
unit_in_source: 16.7 x1000 ksi
method: Value printed in a manufacturer technical datasheet
status: ground
note: The Concast page prints 110310 MPa for the modulus of elasticity in tension. The Aurubis value is used and the difference is listed in gaps.
source: aurubis-c52100
where: Physical properties table, row Mod. of elasticity, metric value
- benchmark: ultimate_tensile_strength
label: Tensile strength, H02 temper, range
value: 475
value_high: 580
bound: range
unit: MPa
scope: material
conditions:
temper: H02 (1/2H)
unit_in_source: 69 to 84 ksi
method: Range printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H02 (1/2H), column Rm, metric value
- benchmark: yield_strength
label: Yield strength Rp0.2, H02 temper, minimum
value: 350
bound: lower
unit: MPa
scope: material
conditions:
temper: H02 (1/2H)
unit_in_source: 51 ksi
method: Minimum value printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H02 (1/2H), column Rp0.2 min, metric value
- benchmark: elongation
label: Elongation, H02 temper, minimum
value: 25
bound: lower
unit: '%'
scope: material
conditions:
temper: H02 (1/2H)
gauge_length: 2 inch
method: Minimum value printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H02 (1/2H), column Elongation 2 inch
- benchmark: ultimate_tensile_strength
label: Tensile strength, H04 hard temper, minimum
value: 585
bound: lower
unit: MPa
scope: material
conditions:
temper: H04 hard
size: 1/4 to 1/2 inch round and hexagonal
unit_in_source: 85 ksi
standard: ASTM B139/B139M
method: Minimum value printed in a manufacturer mechanical properties table
status: ground
source: concast-c52100
where: Mechanical properties table, row 1/4 to 1/2 inch inclusive, column Tensile strength min
- benchmark: elongation
label: Elongation, H04 hard temper, minimum
value: 12
bound: lower
unit: '%'
scope: material
conditions:
temper: H04 hard
size: 1/4 to 1/2 inch round and hexagonal
basis: 4 times diameter
method: Minimum value printed in a manufacturer mechanical properties table
status: ground
source: concast-c52100
where: Mechanical properties table, row 1/4 to 1/2 inch inclusive, column Elongation min
- benchmark: ultimate_tensile_strength
label: Tensile strength, H08 spring temper, range
value: 725
value_high: 820
bound: range
unit: MPa
scope: material
conditions:
temper: H08 (SH) spring
unit_in_source: 105 to 119 ksi
method: Range printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H08 (SH), column Rm, metric value
- benchmark: yield_strength
label: Yield strength Rp0.2, H08 spring temper, minimum
value: 690
bound: lower
unit: MPa
scope: material
conditions:
temper: H08 (SH) spring
unit_in_source: 100 ksi
method: Minimum value printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H08 (SH), column Rp0.2 min, metric value
- benchmark: elongation
label: Elongation, H08 spring temper, minimum
value: 3
bound: lower
unit: '%'
scope: material
conditions:
temper: H08 (SH) spring
gauge_length: 2 inch
method: Minimum value printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H08 (SH), column Elongation 2 inch
- benchmark: ultimate_tensile_strength
label: Tensile strength, H10 extra spring temper, range
value: 760
value_high: 840
bound: range
unit: MPa
scope: material
conditions:
temper: H10 (ES) extra spring
unit_in_source: 110 to 122 ksi
method: Range printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H10 (ES), column Rm, metric value
- benchmark: yield_strength
label: Yield strength Rp0.2, H10 extra spring temper, minimum
value: 725
bound: lower
unit: MPa
scope: material
conditions:
temper: H10 (ES) extra spring
unit_in_source: 105 ksi
method: Minimum value printed in a manufacturer mechanical properties table
status: ground
source: aurubis-c52100
where: Mechanical properties table, row H10 (ES), column Rp0.2 min, metric value
- benchmark: ultimate_tensile_strength
label: Ultimate tensile strength, hard temper (France et al. 1969 data)
value: 690
unit: MPa
scope: material
conditions:
temper: hard
form: strip
unit_in_source: 100 ksi
method: Value in the data file of a University of Waterloo materials page, which cites W.D. France et al., ASTM Journal of Materials, 1969; the source notes the data were digitised from plots and may contain errors
status: ground
source: fde-521-hard
where: Data file header, Su= 690 mpa
- benchmark: yield_strength
label: Yield strength, hard temper (France et al. 1969 data)
value: 510
unit: MPa
scope: material
conditions:
temper: hard
form: strip
method: Value in the data file of a University of Waterloo materials page; digitised from plots
status: ground
source: fde-521-hard
where: Data file header, Sy= 510 mpa
- benchmark: elongation
label: Elongation, hard temper (France et al. 1969 data)
value: 10
unit: '%'
scope: material
conditions:
temper: hard
gauge_length: 2 inch
method: Value in the data file of a University of Waterloo materials page; digitised from plots
status: ground
source: fde-521-hard
where: Data file header, %Elongation= 10 % over 2 inch
corrosion:
- environment: Seawater and weak acids, manufacturer claim
headline: The jtcopper page states a seawater corrosion rate below 0.015 mm/year for C52100.
effect: The page gives this rate in its key features and core advantages sections but names no test method or exposure time. It is recorded as a claim, not a test result.
rating: low
conditions:
basis: manufacturer statement, no test standard named
exposure: seawater, duration not stated
source: jtcopper-c52100
where: Key Features and Core Advantages sections, seawater corrosion rate line
- environment: Air and general service, qualitative
headline: Aurubis rates C52100 as having better corrosion resistance than the other alloys in its family and good sliding properties, with no numeric rate.
effect: The datasheet text says the alloy has better corrosion resistance, and it names no exposure or test. No corrosion rate in mm/year or mpy was printed on any page read in this run.
rating: low
conditions:
basis: qualitative statement from a manufacturer datasheet
exposure: not stated
source: aurubis-c52100
where: Description paragraph
- environment: Alloy chemistry, tin content
headline: Tin is the element that gives phosphor bronze its corrosion resistance and strength.
effect: Wikipedia says tin increases the corrosion resistance and strength of the alloy. The article gives no corrosion data and describes phosphor bronze in general, not C52100 in particular.
rating: low
conditions:
basis: general description, no test data
source: wikipedia-phosphor-bronze
where: Introduction, lead paragraph
risks:
hazards:
- text: The Fisk Alloy SDS lists C52100 in its product identifier and classifies the solid alloy as Not Classified under GHS-US, with No Labeling Applicable. Cutting, welding, melting or grinding produce dust and fume that may cause irritation and metal fume fever, and fine dust in air may present an explosion hazard.
ghs: []
source: fisk-sds
where: Section 2, Hazard(s) identification (classification table and HNOC paragraphs)
- text: The same SDS says tin dust and fume may cause stannosis after chronic exposure, that tin has been shown to increase sarcoma incidence in animal tests, and that long-term phosphorus exposure may affect the kidney and liver.
ghs: []
source: fisk-sds
where: Section 11, Toxicological information, tin and phosphorus paragraphs
failure_risks:
- mode: Fatigue under reversed bending
trigger: Cyclic bending of hard temper strip at stress amplitudes of about 187 to 329 MPa
consequence: In the digitised 1969 data, the sample at 329 MPa failed at 830,340 reversals, and the samples at 187 and 194 MPa reached 200,000,000 reversals without failure.
severity: moderate
source: fde-521-hard
where: Data file table, rows with StsAmpl 329 and runout rows at 187 and 194
- mode: Exceeding the maximum service temperature
trigger: Service above 200 °C
consequence: The jtcopper page prints a maximum service temperature of 200 °C. Above it the spring temper and its strength are not expected to hold, but the page gives no test basis for the limit.
severity: moderate
source: jtcopper-c52100
where: Physical properties table, row Max Service Temp
side_effects: []
handling:
- text: Specify the temper, since H02, H04, H08 and H10 have very different strengths, from 475 to 580 MPa for H02 to 725 to 820 MPa for H08.
source: aurubis-c52100
where: Mechanical properties table, all tempers
- text: H04 hard has a minimum tensile strength of 585 MPa in 1/4 to 1/2 inch round and hexagonal sizes.
source: concast-c52100
where: Mechanical properties table, H04 row
- text: Control dust, fume and sparks when cutting, grinding or welding, since the SDS warns of irritation and a combustible dust hazard.
source: fisk-sds
where: Section 2, Hazard(s) identification
mitigations: []
uses:
- application: electronics-and-chips
device: Connectors and relay springs
example: Aurubis lists connectors, frame connectors, relays and conductor springs among the typical uses of C52100, in automotive and electrical engineering components.
source: aurubis-c52100
where: Typical uses section
- application: mechanisms
device: Springs, slide bearings and bushings
example: Aurubis lists spring rings and slide bearings and bushings among the typical uses of C52100. Wikipedia lists springs, bolts, bushings, bearings and electrical switches with moving or sliding parts among phosphor bronze uses.
source: aurubis-c52100
where: Typical uses section, spring rings, slide bearings and bushings
- application: structures
device: Retaining clamps
example: Aurubis lists retaining clamps among the typical uses of C52100.
source: aurubis-c52100
where: Typical uses section, retaining clamps
supply:
- subject: Copper (remainder of the alloy)
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, 90 FR 50494)
listed: true
recycling: 'USGS: old scrap provided an estimated 160,000 tons of copper in 2025, and about 760,000 tons was recovered from new scrap; scrap contributed about 30 % of U.S. copper supply.'
substitutes:
- 'USGS: aluminum substitutes for copper in electrical equipment and power cable, and optical fiber substitutes for copper in telecommunications applications.'
source: usgs-mcs2026-copper
where: World Mine and Refinery Production and Reserves table, mine production 2025e (world total 23,000; Chile 5,300; Congo (Kinshasa) 3,200; Peru 2,700; China 1,800; Russia 1,300); shares calculated from those values; Critical minerals text; Recycling; Substitutes
- subject: Tin (7.00 to 9.00 % of the alloy)
producers:
- country: China
share_percent: 24.5
year: 2025
- country: Indonesia
share_percent: 21
year: 2025
- country: Peru
share_percent: 11.4
year: 2025
- country: Brazil
share_percent: 9.7
year: 2025
- country: Congo (Kinshasa)
share_percent: 9.3
year: 2025
critical_lists: []
recycling: 'USGS: about 17,000 tons of tin from old and new scrap was estimated to have been recycled in 2025.'
substitutes:
- 'USGS: aluminum, glass, paper, plastic or tin-free steel substitute for tin in cans and containers; epoxy resins substitute for tin in solder.'
source: usgs-mcs2026-tin
where: World Mine Production and Reserves table, mine production 2025e (world total 290,000; China 71,000; Indonesia 61,000; Peru 33,000; Brazil 28,000; Congo (Kinshasa) 27,000); shares calculated from those values; Recycling; Substitutes
documents:
- title: Aurubis, Technical Datasheet C52100 (CuSn8), 18 08 US
type: datasheet
url: https://www.aurubis.be/en/dam/jcr:c9afaa1f-9929-4944-9580-207b545952b6/c52100-cusn8-us.pdf
- title: Concast, C52100 phosphor bronze product page (composition, physical, mechanical and designation tables)
type: datasheet
url: https://concast.com/c52100.php
- title: jtcopper, C52100 bronze product page
type: datasheet
url: https://en.jtcopper.com/c52100-bronze.html
- title: University of Waterloo FDE data file, Phosphor bronze 8 % Sn hard temper (after W.D. France et al., ASTM Journal of Materials, 1969)
type: database
url: https://fde.uwaterloo.ca/Fde/Materials/Other/France/france-PhosphorBronze521-hard.html
- title: 'Wikipedia: Phosphor bronze'
type: database
url: https://en.wikipedia.org/wiki/Phosphor_bronze
- title: Fisk Alloy Safety Data Sheet FAWSDS-5, C51000, C51900, C52100 (revision 11-09-2017)
type: sds
url: https://fiskalloy.com/wp-content/uploads/2023/11/Fisk-Alloy-Safety-Datasheet-FAWSDS-5.pdf
year: 2017
- 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: Tin'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf
year: 2026
gaps:
- 'Critical name conflict: the Concast page prints CW451K for C521, but the Aurubis datasheet prints CW453K for C52100. CW453K is entered. The sister profile bronze-c510 uses CW451K for C51000, so the EN code is not resolved here.'
- 'Melting point conflict: Concast prints solidus 882 °C and liquidus 1027 °C; Aurubis prints a single melting point of 1040 °C (1904 °F). The Concast range is used.'
- 'Thermal conductivity conflict: Concast prints 36 Btu/sq ft/ft hr/°F (62.3 W/m); Aurubis prints 39 Btu/ft h °F (67 W/mK). The Aurubis value is used.'
- 'Modulus conflict: Concast prints 110310 MPa; Aurubis prints 115 GPa. The Aurubis value is used.'
- 'Electrical conductivity: Aurubis prints 12.9 %IACS for the soft condition only, and Concast prints 13 %IACS at 68 °F. The Concast value is used.'
- The jtcopper page prints tensile strengths for H08 (860 to 1035 MPa) and H02 (655 to 795 MPa) that do not match the Aurubis table (725 to 820 MPa and 475 to 580 MPa). The page says its data were synthesized from ASTM, GB, JIS and manufacturer specifications, so its tensile and hardness values are not entered. Only its seawater corrosion claim and max service temperature are used, and both are flagged as claims.
- The Concast table lists only one temper (H04) for ASTM B139. The spring tempers rest on one manufacturer datasheet (Aurubis), so they need a mill certificate check before design use.
- The aircraftmaterials.com CDA 521 page returned HTTP 404 and was not used. The Concast PDF was not retrieved in this run.
- The FDE 1969 values are digitised from plots and come from one source. The FDE page title reads Alloy-C521000, a typo for C52100, and it prints the modulus with no unit, so the modulus is not entered from it.
- No annealing or stress-relief temperature range for C52100 was found in the sources read, so the loss-of-temper failure route is not entered.
- Hardness (Rockwell B 93 typical for H04, Concast) is printed but not entered, because its name is not in the canonical property list.
- The seawater corrosion rate below 0.015 mm/year is an unnamed-test manufacturer claim, not a test result read from a standard.
- Atomic weights for the alloy elements were not found in the sources, so the recipe parts carry weight shares only.
- The USGS tin summary read in this run does not mention a critical minerals list, so the critical list field for tin is empty.
- Outgassing, cold welding and atomic oxygen erosion for C52100 were not searched and no values are recorded.
- The W.Nr. number was not printed on any fetched page and is not entered. The UE9P, DTD265A and CW451K designations printed on the Concast page are not entered as the EN or AFNOR grade codes, because the other sources conflict or do not print them for C52100.
sources:
aurubis-c52100:
title: Aurubis, Technical Datasheet C52100 (CuSn8), 18 08 US
url: https://www.aurubis.be/en/dam/jcr:c9afaa1f-9929-4944-9580-207b545952b6/c52100-cusn8-us.pdf
kind: datasheet
license: Manufacturer datasheet (cited, not reproduced)
concast-c52100:
title: Concast, C52100 phosphor bronze product page
url: https://concast.com/c52100.php
kind: datasheet
license: Manufacturer product page (cited, not reproduced)
jtcopper-c52100:
title: jtcopper, C52100 bronze product page
url: https://en.jtcopper.com/c52100-bronze.html
kind: datasheet
license: Supplier page (cited, not reproduced)
fde-521-hard:
title: University of Waterloo FDE, Phosphor bronze 8 % Sn hard temper, from W.D. France et al., ASTM Journal of Materials, 1969
url: https://fde.uwaterloo.ca/Fde/Materials/Other/France/france-PhosphorBronze521-hard.html
kind: database
license: University web page (cited, not reproduced)
wikipedia-phosphor-bronze:
title: 'Wikipedia: Phosphor bronze'
url: https://en.wikipedia.org/wiki/Phosphor_bronze
kind: web
license: CC BY-SA 4.0 (cited, not reproduced)
fisk-sds:
title: Fisk Alloy Safety Data Sheet FAWSDS-5, C51000, C51900, C52100
url: https://fiskalloy.com/wp-content/uploads/2023/11/Fisk-Alloy-Safety-Datasheet-FAWSDS-5.pdf
year: 2017
kind: datasheet
license: Manufacturer safety data sheet (cited, not reproduced)
usgs-mcs2026-copper:
title: Mineral Commodity Summaries 2026, Copper
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-mcs2026-tin:
title: Mineral Commodity Summaries 2026, Tin
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf
year: 2026
kind: report
license: public domain (USGS)
license: CC-BY-4.0
updated: '2026-10-26'
review:
status: draft
method: assistant
checked_values: 20
unreachable: 2
caveats: 6
note: 'Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry; the USGS PDFs were extracted with pdftotext and the Aurubis datasheet with pdftotext -layout. Unreachable: the aircraftmaterials.com CDA 521 page (HTTP 404) and the Concast PDF (not retrieved). Caveats: the FDE values are digitised from plots; the melting, thermal conductivity and modulus figures conflict between Concast and Aurubis; the spring tempers rest on a single datasheet; the jtcopper tensile values conflict with the other sources and are not used; the EN code CW451K versus CW453K is unresolved.'
story:
risk_groups:
- title: For people
lead: The opened sources give a hazard for dust and fume from the alloy, not for the solid metal.
level: 1
verdict: Dust and fume, not solid metal
points:
- label: Solid alloy
line: The Fisk SDS classifies the solid alloy as Not Classified under GHS-US, with no labelling. Hazards come from the dust, fume and powder made when it is cut, ground or welded.
- label: Tin and phosphorus in dust
line: The same SDS says tin dust and fume can cause stannosis after chronic exposure and that tin has been shown to increase sarcoma incidence in animal tests. It also says long-term phosphorus exposure may affect the kidney and liver.
- title: If it fails
lead: The failure routes in the sources are fatigue in hard temper strip and use above the printed service limit.
points:
- label: Fatigue
line: In the digitised 1969 data, a sample at 329 MPa stress amplitude failed at 830,340 reversals, and samples at 187 and 194 MPa reached 200,000,000 reversals without failure.
- label: Service limit
line: The jtcopper page prints a maximum service temperature of 200 °C. It gives no test basis for that figure.
- title: Handling and storage
points:
- label: Specify the temper
line: H02 has 475 to 580 MPa tensile strength, H08 spring has 725 to 820 MPa, and H10 extra spring has 760 to 840 MPa. Choose the temper before the strength is quoted.
- label: Dust
line: Control dust, fume and sparks when cutting, grinding or welding.
why: Phosphor bronze C52100 is a copper alloy with about 8 % tin and 0.2 % phosphorus. Aurubis calls it the highest alloyed phosphor bronze in its family, and the tin gives it high strength with still adequate conductivity. The Aurubis table gives 725 to 820 MPa tensile for the H08 spring temper, and Concast gives 585 MPa minimum for H04 hard. The alloy is used for springs, connectors, relays and slide bearings.
uses:
- where: Connectors and relays
line: Aurubis lists connectors, frame connectors, relays and conductor springs among the typical uses of C52100.
- where: Springs and slide bearings
line: Aurubis lists spring rings, slide bearings and bushings. Wikipedia lists springs, bolts, bushings and bearings among phosphor bronze uses.
- where: Retaining clamps
line: Aurubis lists retaining clamps among the typical uses of C52100.
can_do:
- label: Carry springs
value: 725 to 820 MPa tensile
benchmark: ultimate_tensile_strength
line: The H08 spring temper has a tensile range of 725 to 820 MPa, with a minimum yield of 690 MPa (Aurubis).
- label: Take the density
value: 8.79 g/cm3
benchmark: density
line: The Aurubis datasheet gives a density of 8.79 g/cm3 at 20 °C.
- label: Conduct electricity
value: 13 %IACS
benchmark: electrical_conductivity
line: The Concast page gives an electrical conductivity of 13 %IACS at 68 °F.
- label: Melt
value: 882 to 1027 °C
benchmark: melting_point
line: The solidus is 882 °C and the liquidus is 1027 °C in the Concast table. The Aurubis datasheet gives a single melting point of 1040 °C.
compare: Among the phosphor bronzes, C52100 is the highest-tin member (7.00 to 9.00 % tin in the ASTM B139 limits). Its strength in the spring tempers is the highest of the tin-bronze grades read here, and its electrical conductivity is 13 %IACS. The lower-tin C51000 grade has its own profile, bronze-c510, for direct comparison.
compare_rows:
- label: Density
benchmark: density
- label: Electrical conductivity
benchmark: electrical_conductivity
- label: Thermal expansion
benchmark: cte
handling:
- Specify the temper, since the strength depends strongly on it.
- 'Solder and braze the alloy: the Aurubis fabrication table rates soldering and brazing as excellent.'
- Control dust, fume and sparks when cutting, grinding or welding.
good_for:
- 'Springs and connectors: the H08 spring temper gives 725 to 820 MPa tensile strength, with 690 MPa minimum yield (Aurubis).'
- 'Slide bearings and bushings: Aurubis rates the alloy for good sliding properties and wear resistance.'
- 'Solderable and brazeable parts: Aurubis rates soldering and brazing as excellent.'
watch_out:
- Dust and fume when cut, ground or welded, per the Fisk SDS.
- Spring tempers rest on one manufacturer datasheet, so confirm the temper on a mill certificate.
- The seawater corrosion rate below 0.015 mm/year is a manufacturer claim without a named test.
- Melting, thermal conductivity and modulus figures differ between the Concast and Aurubis sources.
verdict: Phosphor bronze C52100 is the highest-tin member of the phosphor bronze family, with 7.00 to 9.00 % tin. Its strength depends strongly on temper, and the H08 spring temper gives 725 to 820 MPa tensile strength. The alloy solders and brazes well, and dust from machining is the main hazard. This profile lacks a verified seawater test, a confirmed EN code and an annealing range.
recipe:
line: 'C52100 is a copper-tin-phosphorus alloy: copper is the matrix, and tin gives most of the strength and the corrosion resistance. Phosphorus is a trace addition that Wikipedia says raises wear resistance and stiffness. Lead, zinc and iron are impurity limits, and the wrought bar, rod, wire and strip are made by cold working and annealing.'
parts:
- name: Copper
symbol: Cu
share: remainder
role: The matrix. Concast and the ASTM B139 composition table give copper as the remainder.
- name: Tin
symbol: Sn
share: 7.00 to 9.00 %
role: Gives most of the strength and corrosion resistance (Concast composition table, Wikipedia).
- name: Phosphorus
symbol: P
share: 0.03 to 0.35 %
role: A trace addition that raises wear resistance and stiffness (Wikipedia).
- name: Lead
symbol: Pb
share: 0.05 % max
role: Impurity limit.
- name: Zinc
symbol: Zn
share: 0.20 % max
role: Impurity limit.
- name: Iron
symbol: Fe
share: 0.10 % max
role: Impurity limit.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Aurubis, Technical Datasheet C52100 (CuSn8), 18 08 US | datasheet | 17 values | ||
| Concast, C52100 phosphor bronze product page | datasheet | 7 values | ||
| jtcopper, C52100 bronze product page | datasheet | 2 values | ||
| University of Waterloo FDE, Phosphor bronze 8 % Sn hard temper, from W.D. France et al., ASTM Journal of Materials, 1969 | database | 4 values | ||
| Wikipedia: Phosphor bronze | web | 1 value | ||
| Fisk Alloy Safety Data Sheet FAWSDS-5, C51000, C51900, C52100 | datasheet | 2017 | 3 values | |
| Mineral Commodity Summaries 2026, Copper | report | 2026 | 1 value | |
| Mineral Commodity Summaries 2026, Tin | report | 2026 | 1 value |