Stainless steel 431 431 (UNS S43100, EN 1.4057)
Fe balance with 15.0 to 17.0 Cr, 1.5 to 2.5 Ni, 0.12 to 0.22 C, up to 1.5 Mn, 1.0 Si, 0.04 P and 0.03 S (wt%, EN 10088-3 limits for 1.4057, as printed by Smiths High Performance and Team Edelstahl)
Also known as UNS S43100, EN 1.4057, EN name X17CrNi16-2, AISI 431, JIS SUS 431, BS 431S29 · 3 more
Type 431 (UNS S43100, EN 1.4057, X17CrNi16-2) is a martensitic chromium-nickel stainless steel with 15 to 17 percent chromium and 1.5 to 2.5 percent nickel (EN 10088-3 limits, Smiths High Performance and Team Edelstahl).
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.
Strength
850 to 1000 MPa
Toughness
25 J
Weight
7800 kg/m3
Thermal
25 W/(m·K)
Usable range
-40 to 400 °C
Recipe, share of the weight
- Fe balance (the rest)Iron
- Cr 15 to 17%Chromium
- Ni 1.5 to 2.5%Nickel
- C 0.12 to 0.22%Carbon
- Mn 0 to 1.5%Manganese
- Si 0 to 1%Silicon
- P 0 to 0.04%Phosphorus
- S 0 to 0.03%Sulfur
Best for
High tensile and torsional strength in shafts, valve stems and pump parts that also need reasonable corrosion resistance (Smith Metal, Smiths High Performance)
Weakest at
Welding and cold forming: welds crack unless preheated, and the grade is not recommended for cold heading or bending (Smiths High Performance, Voestalpine)
Risk at a glance
- People Low. Chromium and nickel alloy, not a safety data sheet
- If it fails Moderate. Intergranular corrosion from chromium carbides
- Corrosion Moderate. Considerable resistance to salt water, described as similar to Type 304.
Quick facts: 431 (UNS S43100, EN 1.4057)
| Property | Value | Basis |
|---|---|---|
| Density | 7.8 g/cm³ | 1 sourced value |
| Yield strength | 600 to 1,034 MPa | 5 sourced values across conditions |
| Tensile strength | 800 to 1,379 MPa | 4 sourced values across conditions |
| Young's modulus | 200 to 215 GPa | 2 sourced values across conditions |
| Hardness (Brinell) | 260 to 331 HB | 3 sourced values across conditions |
| Thermal conductivity | 25 W/(m·K) | 1 sourced value |
| Thermal expansion (CTE) | 10 ppm/K | 1 sourced value |
| Specific heat | 460 J/(kg·K) | 1 sourced value |
| Electrical resistivity | 0.7 ohm mm2/m | 1 sourced value |
| Maximum service temperature | 400 °C | 1 sourced value |
What is the density of Stainless steel 431?
Stainless steel 431 has a density of 7.8 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Stainless steel 431?
Stainless steel 431 has a thermal conductivity of 25 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 Stainless steel 431?
Stainless steel 431 has a coefficient of thermal expansion of 10 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the yield strength of Stainless steel 431?
Stainless steel 431 has a yield strength of 600 to 1,034 MPa. The range covers 5 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 tensile strength of Stainless steel 431?
Stainless steel 431 has a tensile strength of 800 to 1,379 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 Stainless steel 431?
Stainless steel 431 is also written as UNS S43100, EN 1.4057, EN name X17CrNi16-2, AISI 431, JIS SUS 431, BS 431S29. Each code is printed in the source listed beside it in the designations table.
What is Stainless steel 431 used for?
Uses recorded in the sources include Pump and propeller shafts, outboard drive shafts, valve stems and axles; Pumps, valves, piston rods and compressor impellers; Bolts, fasteners and bearings.
Why it exists
Type 431 is a martensitic stainless steel that combines high tensile and torsional strength with reasonable corrosion resistance and toughness. Smith Metal and Smiths High Performance name shafts, valve stems and pump parts as typical uses. Its chemistry is 15 to 17 percent chromium and 1.5 to 2.5 percent nickel, and after heat treatment it reaches 850 to 1000 MPa tensile strength (Voestalpine, Smith Metal). Welding and cold forming are its limits, and Team Edelstahl notes the chromium carbide route to intergranular corrosion.
Where it's used
Shafts, valve stems and axles
Smith Metal lists pump and propeller shafts, outboard drive shafts, valve stems and axles among typical applications.
Pumps, valves and compressor parts
Team Edelstahl says it is often used for heavily loaded parts such as pumps, valves, piston rods and compressor impellers.
Motorsport and fasteners
Smiths High Performance lists valve stems, bolts and fasteners, bearings and pump shafts as motorsport applications.
Recipe
Fe balance with 15.0 to 17.0 Cr, 1.5 to 2.5 Ni, 0.12 to 0.22 C, up to 1.5 Mn, 1.0 Si, 0.04 P and 0.03 S (wt%, EN 10088-3 limits for 1.4057, as printed by Smiths High Performance and Team Edelstahl)
Type 431 is an iron-chromium-nickel martensitic steel, supplied as bar, plate, sheet and tube (Smith Metal). Voestalpine recommends a soft anneal with slow furnace cooling, hardening in oil or air, and tempering with at least one hour at temperature followed by air cooling. Team Edelstahl gives the same EN ranges as Smiths High Performance.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Iron Fe | balance (the rest) | The matrix of the alloy. Quench and tempering turn it into martensite, which gives the high strength. |
| Chromium Cr | 15 to 17% | Forms the passive oxide film that gives corrosion resistance. Voestalpine's average analysis sits in the upper part of this range. |
| Nickel Ni | 1.5 to 2.5% | Adds toughness and corrosion resistance over 13 percent chromium steels (Team Edelstahl). Swiss Steel and Smith Metal print a minimum of 1.25 percent. |
| Carbon C | 0.12 to 0.22% | Gives the hardness that hardening produces. Voestalpine's average analysis is at the upper end of this range. |
| Manganese Mn | 0 to 1.5% | Deoxidiser held at up to 1.5 percent in the EN limits; Smith Metal prints a lower upper limit. |
| Silicon Si | 0 to 1% | Deoxidiser held at up to 1.0 percent. |
| Phosphorus P | 0 to 0.04% | Impurity held at up to 0.04 percent. |
| Sulfur S | 0 to 0.03% | Impurity held at up to 0.03 percent. |
Weight shares are as printed in the sources.
What it can do
Strength
850 to 1000 MPa
measured
Heat treated, the tensile strength is 850 to 1000 MPa with a yield strength of 600 MPa and 12 percent elongation (Voestalpine). Smiths High Performance gives 800 to 950 MPa for QT800 at 60 to 160 mm.
Toughness
25 J
measured
Voestalpine gives 25 J impact toughness for the heat-treated condition, and Swiss Steel gives a minimum of 27 J ISO-V for QT800 at 20 to 160 mm.
Weight
7800 kg/m3
measured
Smiths High Performance gives a density of 7800 kg/m3. Team Edelstahl prints 7.0 kg/dm3, which conflicts with it and is not used.
Thermal
25 W/(m·K)
measured
Thermal conductivity is 25 W/(m·K) at 20 °C (Abrams) and 20.2 W/(m·K) at 100 °C (Smiths High Performance).
Usable range
-40 to 400 °C
measured
Team Edelstahl says the grade can be used from -40 °C to 400 °C.
How it compares
Team Edelstahl says 1.4057 has better toughness and corrosion resistance than comparable 13 percent chromium steels, and is widely used where heavily loaded machine parts need strength. Smith Metal compares its corrosion resistance with Type 304 and Smiths High Performance says it is the most corrosion resistant of the martensitic grades. Voestalpine says it can not be readily cold worked, which limits forming compared with more ductile grades.
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 | 431 (UNS S43100, EN 1.4057) | 410 (UNS S41000) | 440C (UNS S44004) | S41500 (F6NM forged, CA6NM cast) | 410S (UNS S41008) | 416 | 420 | 1.4418 (X4CrNiMo16-5-1) |
|---|---|---|---|---|---|---|---|---|
| Capacity and energy | ||||||||
| Impact toughness, heat treated | 25 J11 | no data | no data | no data | no data | no data | no data | no data |
| Impact energy ISO-V, QT800 minimumMinimum value printed in a supplier datasheet | > 27 J12 | no data | no data | no data | no data | no data | no data | no data |
| Thermal behavior and safety | ||||||||
| Thermal conductivity at 20 °CValue printed in a steel-grade datasheet | 25 W/(m·K)1 | 24.9 W/m-K | 24.2 W/m.K | 25 W/(m K) | 26.9 W/m-K | 30 W/m K | 24.9 W/(m·K) | 15 W/m K |
| Thermal conductivity at 100 °CValue printed in a stockholder datasheet | 20.2 W/(m·K) | 24.9 W/m-K | 24.2 W/m.K | 25 W/(m K) | 26.9 W/m-K | 30 W/m K | 24.9 W/(m·K) | 15 W/m K |
| Specific heat capacity at 20 °CValue printed in a steel-grade datasheet | 460 J/(kg·K)2 | 0.46 kJ/(kg·K) | no data | 430 J/(kg K) | 0.46 kJ/kg·K | 460 J/kg K | 460 J/(kg·K) | 430 J/kg K |
| Physical and electrical | ||||||||
| Density, Smiths High Performance datasheetValue printed in a stockholder datasheet | 7800 kg/m3 | 7.73 g/cm³ | 0.275 lb/in3 | 7.61 to 8.1 kg/dm3 | 7.73 g/cm³ | 7.7 kg/dm3 | 7.75 g/cm³ | 7.7 kg/dm3 |
| Electrical resistivity at 20 °CValue printed in a steel-grade datasheet | 0.7 ohm mm2/m4 | 57 µohm-cm | 0.6 10-6 ohm.m | no data | 60 µohm-cm | 0.6 Ω mm2/m | 0.55 µΩ·m | no data |
| Hardness, annealedTypical value printed on the page | 260 HB | no data | no data | no data | no data | < 220 HB | < 241 HB | no data |
| Hardness, delivery condition, maximumMaximum value printed in a steel-grade datasheet | < 331 HB | no data | no data | no data | no data | < 220 HB | < 241 HB | no data |
| Hardness, QT800 maximumMaximum value printed in a supplier datasheet | < 321 HBW | no data | no data | no data | no data | < 220 HB | < 241 HB | no data |
| Other measurements | ||||||||
| Modulus of elasticity at 20 °CValue printed in a steel-grade datasheet | 215 kN/mm23 | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa |
| Modulus of elasticity, temperature not statedValue printed in a stockholder datasheet | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa |
| Mean coefficient of thermal expansion, 20 to 100 °C | 10 ppm/K5 | 9.9 µm/m-°C | 10.1 10-6/K | no data | 10.8 µm/m·K | 10.5 10^-6/K | 10.3 10^-6/K | 10.8 10-6 K-1 |
| Tensile strength, annealedTypical value printed on the page | 862 MPa | 450 to 510 MPa | 1965 MPa | < 1100 MPa | > 60 ksi | 650 to 850 N/mm2 | 85.8 ksi | 760 to 960 MPa |
| Tensile strength, heat treated to AMS 5628Typical value printed on the page | 1379 MPa | 450 to 510 MPa | 1965 MPa | < 1100 MPa | > 60 ksi | 650 to 850 N/mm2 | 85.8 ksi | 760 to 960 MPa |
| Tensile strength, heat treatedRange printed in a steel-grade datasheet | 850 to 1000 MPa | 450 to 510 MPa | 1965 MPa | < 1100 MPa | > 60 ksi | 650 to 850 N/mm2 | 85.8 ksi | 760 to 960 MPa |
| Tensile strength, QT800 at 60 to 160 mmRange printed in a stockholder datasheet | 800 to 950 MPa6 | 450 to 510 MPa | 1965 MPa | < 1100 MPa | > 60 ksi | 650 to 850 N/mm2 | 85.8 ksi | 760 to 960 MPa |
| Yield strength, heat treated | 600 MPa7 | 205 to 290 MPa | 1896 MPa | > 520 MPa | > 30 ksi | > 450 MPa | 51.5 ksi | > 550 MPa |
| Proof stress 0.2 percent, annealedTypical value printed on the page | 655 MPa | 205 to 290 MPa | 1896 MPa | > 520 MPa | > 30 ksi | > 450 MPa | 51.5 ksi | > 550 MPa |
| Proof stress 0.2 percent, heat treated to AMS 5628Typical value printed on the page | 1034 MPa | 205 to 290 MPa | 1896 MPa | > 520 MPa | > 30 ksi | > 450 MPa | 51.5 ksi | > 550 MPa |
| Proof stress, T condition, minimumMinimum value printed in a stockholder datasheet | > 665 MPa | 205 to 290 MPa | 1896 MPa | > 520 MPa | > 30 ksi | > 450 MPa | 51.5 ksi | > 550 MPa |
| Rp0.2, QT800 at 20 to 160 mm, minimumMinimum value printed in a supplier datasheet | > 620 MPa8 | 205 to 290 MPa | 1896 MPa | > 520 MPa | > 30 ksi | > 450 MPa | 51.5 ksi | > 550 MPa |
| Elongation, annealedTypical value printed on the page | 20 %9 | 20 to 34 % | 2 % | 15 % | > 22 % | > 12 % | 12 to 13 % | > 16 % |
| Elongation, heat treated to AMS 5628Typical value printed on the page | 10 %10 | 20 to 34 % | 2 % | 15 % | > 22 % | > 12 % | 12 to 13 % | > 16 % |
| Elongation, heat treatedValue printed in a steel-grade datasheet | 12 % | 20 to 34 % | 2 % | 15 % | > 22 % | > 12 % | 12 to 13 % | > 16 % |
| Usable temperature, upper limitRange printed in a steel-grade datasheet | 400 °C | < 649 °C | 400 °C | 300 °C | < 705 °C | 675 °C | < 675 °C | 300 °C |
| Usable temperature, lower limitRange printed in a steel-grade datasheet | -40 °C | no data | no data | -60 °C | no data | no data | no data | -30 °C |
Why choose it, and why not
Good for
- Shafts, valve stems and pump parts that need high strength and torsional capacity (Smith Metal, Smiths High Performance).
- Heavily loaded machine parts, such as pumps, valves and piston rods (Team Edelstahl).
- Parts that will be nitrided for surface hardness, though corrosion resistance drops after nitriding (Smiths High Performance).
Watch out for
- Welding cracks without preheat (Smiths High Performance, Smith Metal).
- Carbide formation can cause intergranular corrosion (Team Edelstahl).
- Nitriding lowers corrosion resistance (Smiths High Performance).
- No salt-spray result, corrosion rate or cryogenic toughness figure was found, and service is quoted only to -40 °C (Team Edelstahl).
Type 431 is the high-strength martensitic grade for shafts, valve stems and pump parts. It reaches 850 to 1000 MPa tensile strength when heat treated and resists salt water reasonably well. Welding needs preheat, cold forming is limited, and carbides can cause intergranular corrosion. Its strength figures are manufacturer values for specific heat treatments and forms, and it has no 431 safety data sheet in this profile.
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 | S43100 |
| EN | 1.4057 |
| EN name | X17CrNi16-2 |
| AISI | 431 |
| JIS | SUS 431 |
| BS | 431S29 |
| ASTM | A276 (bar) |
| AMS | 5628 (bars, wire and forgings, heat treated) |
| Trade name | Acidur 4057 |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Thermal conductivity at 20 °C | — | grade 1.4057 (X17CrNi16-2)temperature 20 °Cunit in source W/(m • K) | — |
| 2 | Specific heat capacity at 20 °C | — | grade 1.4057temperature 20 °Cunit in source J/kg K | — |
| 3 | Modulus of elasticity at 20 °C | — | grade 1.4057temperature 20 °Cunit in source kN / mm² | — |
| 4 | Electrical resistivity at 20 °C | — | grade 1.4057temperature 20 °Cunit in source (ohm) mm²/m | — |
| 5 | Mean coefficient of thermal expansion, 20 to 100 °C | Value printed in a steel-grade datasheet, table of thermal expansion coefficients | grade AISI/SAE 431 (1.4057)temperature 20 to 100 °Cunit in source 10-6 m/(m·K) | — |
| 6 | Tensile strength, QT800 at 60 to 160 mm | — | condition QT800 quench and temperedthickness 60 to 160 mmbasis BS EN 10088-3, 1.4057 | — |
| 7 | Yield strength, heat treated | Value printed in a steel-grade datasheet, shown as a single value | condition heat treated (recommended heat treatment)product not stated | — |
| 8 | Rp0.2, QT800 at 20 to 160 mm, minimum | — | condition QT800thickness 20 to 160 mm, longitudinalbasis BS EN 10088-3 table | — |
| 9 | Elongation, annealed | — | condition annealedgauge length 2 inproduct not stated | — |
| 10 | Elongation, heat treated to AMS 5628 | — | condition heat treated to AMS 5628gauge length 2 inproduct not stated | — |
| 11 | Impact toughness, heat treated | Value printed in a steel-grade datasheet, shown as a single value | condition heat treatedtest temperature not stated | — |
| 12 | Impact energy ISO-V, QT800 minimum | — | condition QT800thickness 20 to 160 mm, longitudinaltest temperature not stated | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Salt water and marine atmosphere | moderate | Considerable resistance to salt water, described as similar to Type 304.1 |
| Nitrided surface | moderate | Nitriding raises hardness and fatigue resistance but lowers corrosion resistance.2 |
| Carbide-sensitised zones after heat treatment or welding | moderate | Chromium carbides can make the alloy prone to intergranular corrosion.3 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Salt water and marine atmosphere | Smith Metal says the alloy offers considerable resistance to saltwater and is used widely in marine equipment, and rates its corrosion resistance as similar to Type 304. No salt-spray test result or corrosion rate is printed. | basis manufacturer statement, no test conditions printed |
| 2 | Nitrided surface | Smiths High Performance says 431 has the highest corrosion resistance of all martensitic stainless steels, although resistance reduces once the material is nitrided. Nitriding increases hardness and fatigue resistance. | basis manufacturer statement, no test conditions printed |
| 3 | Carbide-sensitised zones after heat treatment or welding | Team Edelstahl says the grade is susceptible to intergranular corrosion because chromium carbides form and deplete chromium in some areas. It gives PREN 17.5 to 21.2, and says the maximum corrosion resistance is reached with a bare metallic surface. | basis manufacturer statement, PREN as printed |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
No 431 safety data sheet was read. The hazard record is for elemental chromium, and it does not name the alloy.
- Chromium
- PubChem lists sensitisation codes H317 and H334 and eye irritation code H319 for elemental chromium in its aggregated notifications.
In the environment
Smith Metal calls the alloy resistant to salt water and widely used in marine equipment, and Smiths High Performance says it has the highest corrosion resistance of the martensitic grades.
- Salt water
- Smith Metal says the alloy offers considerable resistance to saltwater, similar to Type 304. No salt-spray result is printed.
- Nitriding
- Smiths High Performance says nitriding raises hardness and fatigue resistance, but corrosion resistance reduces once the material is nitrided.
Welding and heat
Welds crack without preheat and can lose corrosion resistance through carbide formation.
- Weld
- Team Edelstahl recommends heating to 100 to 300 °C before welding and avoiding cooling below 200 °C while welding. Smith Metal also recommends preheat.
- Carbides
- Team Edelstahl says chromium carbide formation depletes chromium in some areas and makes the grade prone to intergranular corrosion.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Intergranular corrosion from chromium carbidesmoderate severity | Heat treatment or welding that lets chromium carbides form along grain boundaries and deplete chromium next to themTeam Edelstahl says the grade is susceptible to intergranular corrosion, so corrosion resistance falls in the affected zones. |
| Cracking in weldsmoderate severity | Welding without preheatSmiths High Performance says welding is more complicated and susceptible to cracking unless pre-heated. Smith Metal says welding is difficult and recommends preheating. |
| Lower corrosion resistance after nitridinglow severity | Nitriding the surface for hardness or fatigue resistanceSmiths High Performance says corrosion resistance reduces once the material is nitrided. |
| Property loss from hydrogen or nitrogen gas during weldingmoderate severity | Welding under gases that contain hydrogen or nitrogenTeam Edelstahl says such gases have a negative effect on the mechanical properties of the weld. |
Handling and storage
- Voestalpine says the grade cannot be readily cold worked and is not recommended for cold heading and bending.
- Team Edelstahl says it can be welded only with precautions, and recommends heating to 100 to 300 °C before welding and avoiding cooling below 200 °C during welding.
- Team Edelstahl says tempering colours must be removed chemically or mechanically after welding to keep corrosion resistance in the weld.
Mitigations
- Preheat before welding, and keep the weld below 200 °C while it is made (Team Edelstahl). Smiths High Performance and Smith Metal also recommend preheat.
Supply and geography
How common the raw materials are and where they come from.
Chromium
World mine production of chromite was 51,000 thousand t gross weight in 2025 (estimated). World resources are greater than 12 billion t of shipping-grade chromite, 95 percent in Kazakhstan and southern Africa (USGS 2026).
- Top producers (2025)
- South Africa 45.1%, Turkey 17.6%, Kazakhstan 13.7%, India 5.9%, Zimbabwe 3.9%, Brazil 3.9%
- Recycling
- USGS says recycled chromium, contained in reported stainless-steel scrap receipts, accounted for 21 percent of the chromium total in 2025.
Nickel
World mine production of nickel was an estimated 3.9 million t in 2025, and world reserves are greater than 140 million t (USGS 2026).
- Top producers (2025)
- Indonesia 66.7%, Philippines 6.9%, Russia 5.1%
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.
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spore: profile
id: stainless-431
spore_version: 0.2
family: stainless-martensitic
name: Stainless steel 431
abbreviation: 431 (UNS S43100, EN 1.4057)
role: high-strength shaft and valve-stem stainless
category: metals
type: steels-and-stainless
summary: Type 431 (UNS S43100, EN 1.4057, X17CrNi16-2) is a martensitic chromium-nickel stainless steel with 15 to 17 percent chromium and 1.5 to 2.5 percent nickel (EN 10088-3 limits, Smiths High Performance and Team Edelstahl). Heat treated, it reaches 800 to 1000 MPa tensile strength with 12 percent elongation and good toughness. Smith Metal and Team Edelstahl list pump and propeller shafts, valve stems and pump parts as typical uses. Smiths High Performance calls it the most corrosion resistant of the martensitic grades, but it cracks in welds unless it is preheated.
best_for: High tensile and torsional strength in shafts, valve stems and pump parts that also need reasonable corrosion resistance (Smith Metal, Smiths High Performance)
weakest_at: 'Welding and cold forming: welds crack unless preheated, and the grade is not recommended for cold heading or bending (Smiths High Performance, Voestalpine)'
identity:
formula: Fe balance with 15.0 to 17.0 Cr, 1.5 to 2.5 Ni, 0.12 to 0.22 C, up to 1.5 Mn, 1.0 Si, 0.04 P and 0.03 S (wt%, EN 10088-3 limits for 1.4057, as printed by Smiths High Performance and Team Edelstahl)
source: team-1-4057
where: Chemische Zusammensetzung table, min and max rows (C, Mn, Si, P, S, Cr, Ni), cross-checked with the Smiths High Performance chemical composition table
designations:
- system: UNS
code: S43100
source: aircraftmaterials-431
where: Designations block of the Aircraft Materials page, UNS S43100
- system: EN
code: '1.4057'
source: team-1-4057
where: Normen und Bezeichnungen table, row EN
- system: EN name
code: X17CrNi16-2
source: team-1-4057
where: Normen und Bezeichnungen table, row DIN
- system: AISI
code: '431'
source: abrams-1-4057
where: Header block, field AISI/SAE, and the composition table heading AISI/SAE 431
- system: BS
code: 431S29
source: aircraftmaterials-431
where: Designations block of the Aircraft Materials page, line BS 970; 431S29
- system: ASTM
code: A276
note: bar
source: aircraftmaterials-431
where: Designations block of the Aircraft Materials page, line ASTM A276 / ASME SA276
- system: AMS
code: '5628'
note: bars, wire and forgings, heat treated
source: aircraftmaterials-431
where: Typical Mechanical Properties table, heat treated row, and the designations block line AMS 5628 Bars / wire / forgings
- system: JIS
code: SUS 431
source: swiss-dew-2018
where: Material description line on the bar page 11, Acidur 4057, 1.4057, Type 431, SUS 431
- system: Trade name
code: Acidur 4057
source: swiss-dew-2018
where: Material description line on the bar page 11
tags:
environments: []
stresses: []
applications:
- mechanisms
- structures
properties:
- benchmark: density
label: Density, Smiths High Performance datasheet
value: 7800
unit: kg/m3
scope: material
conditions:
grade: 1.4057, properties as per BS EN 10088-3
temperature: not stated
method: Value printed in a stockholder datasheet
status: ground
source: smiths-431
where: Physical Properties table, row Density
- benchmark: thermal_conductivity
label: Thermal conductivity at 20 °C
value: 25
unit: W/(m·K)
scope: material
conditions:
grade: 1.4057 (X17CrNi16-2)
temperature: 20 °C
unit_in_source: W/(m • K)
method: Value printed in a steel-grade datasheet
status: ground
source: abrams-1-4057
where: Physical properties block, Thermal conductivity row, 20°C value
- benchmark: thermal_conductivity
label: Thermal conductivity at 100 °C
value: 20.2
unit: W/(m·K)
scope: material
conditions:
grade: '1.4057'
temperature: 100 °C
method: Value printed in a stockholder datasheet
status: ground
source: smiths-431
where: Physical Properties table, row Thermal Conductivity at 100°C
- benchmark: specific_heat
label: Specific heat capacity at 20 °C
value: 460
unit: J/(kg·K)
scope: material
conditions:
grade: '1.4057'
temperature: 20 °C
unit_in_source: J/kg K
method: Value printed in a steel-grade datasheet
status: ground
source: team-1-4057
where: Physikalische Eigenschaften table, column Spezifische Wärmekapazität, row bei 20°C
- benchmark: elastic_modulus
label: Modulus of elasticity at 20 °C
value: 215
unit: kN/mm2
scope: material
conditions:
grade: '1.4057'
temperature: 20 °C
unit_in_source: kN / mm²
method: Value printed in a steel-grade datasheet
status: ground
source: team-1-4057
where: Mechanische Eigenschaften table, column Elastizitätsmodul, row bei 20°C
- benchmark: elastic_modulus
label: Modulus of elasticity, temperature not stated
value: 200
unit: GPa
scope: material
conditions:
grade: 1.4057, properties as per BS EN 10088-3
temperature: not stated
method: Value printed in a stockholder datasheet
status: ground
source: smiths-431
where: Physical Properties table, row Modulus of Elasticity
- benchmark: electrical_resistivity
label: Electrical resistivity at 20 °C
value: 0.7
unit: ohm mm2/m
scope: material
conditions:
grade: '1.4057'
temperature: 20 °C
unit_in_source: (ohm) mm²/m
method: Value printed in a steel-grade datasheet
status: ground
source: team-1-4057
where: Physikalische Eigenschaften table, column Elektrischer Widerstand, row bei 20°C
- benchmark: cte
label: Mean coefficient of thermal expansion, 20 to 100 °C
value: 10
unit: ppm/K
scope: material
conditions:
grade: AISI/SAE 431 (1.4057)
temperature: 20 to 100 °C
unit_in_source: 10-6 m/(m·K)
method: Value printed in a steel-grade datasheet, table of thermal expansion coefficients
status: ground
source: abrams-1-4057
where: Thermal expansion coefficient table, column 20-100°C
- benchmark: ultimate_tensile_strength
label: Tensile strength, annealed
value: 862
unit: MPa
scope: material
conditions:
condition: annealed
product: not stated
method: Typical value printed on the page
status: ground
source: aircraftmaterials-431
where: Typical Mechanical Properties table, row Alloy 431 Annealed, column Tensile Strength
- benchmark: ultimate_tensile_strength
label: Tensile strength, heat treated to AMS 5628
value: 1379
unit: MPa
scope: material
conditions:
condition: heat treated to AMS 5628
product: not stated
method: Typical value printed on the page
status: ground
source: aircraftmaterials-431
where: Typical Mechanical Properties table, row Alloy 431 Heat Treated AMS 5628, column Tensile Strength
- benchmark: ultimate_tensile_strength
label: Tensile strength, heat treated
value: 850
value_high: 1000
bound: range
unit: MPa
scope: material
conditions:
condition: heat treated (recommended heat treatment, quench and tempered supply condition)
product: not stated
method: Range printed in a steel-grade datasheet
status: ground
source: voest-431
where: MECHANICAL PROPERTIES (HEAT TREATED) table, column Tensile Mpa (Rm)
- benchmark: ultimate_tensile_strength
label: Tensile strength, QT800 at 60 to 160 mm
value: 800
value_high: 950
bound: range
unit: MPa
scope: material
conditions:
condition: QT800 quench and tempered
thickness: 60 to 160 mm
basis: BS EN 10088-3, 1.4057
method: Range printed in a stockholder datasheet
status: ground
source: smiths-431
where: Mechanical Properties table, row Ultimate Tensile Strength, footnote QT800 60-160mm
- benchmark: yield_strength
label: Yield strength, heat treated
value: 600
unit: MPa
scope: material
conditions:
condition: heat treated (recommended heat treatment)
product: not stated
method: Value printed in a steel-grade datasheet, shown as a single value
status: ground
source: voest-431
where: MECHANICAL PROPERTIES (HEAT TREATED) table, column Yield Strength (MPa)
- benchmark: yield_strength
label: Proof stress 0.2 percent, annealed
value: 655
unit: MPa
scope: material
conditions:
condition: annealed
product: not stated
method: Typical value printed on the page
status: ground
source: aircraftmaterials-431
where: Typical Mechanical Properties table, row Alloy 431 Annealed, column Proof Stress 0.2%
- benchmark: yield_strength
label: Proof stress 0.2 percent, heat treated to AMS 5628
value: 1034
unit: MPa
scope: material
conditions:
condition: heat treated to AMS 5628
product: not stated
method: Typical value printed on the page
status: ground
source: aircraftmaterials-431
where: Typical Mechanical Properties table, row Alloy 431 Heat Treated AMS 5628, column Proof Stress 0.2%
- benchmark: yield_strength
label: Proof stress, T condition, minimum
value: 665
bound: lower
unit: MPa
scope: material
conditions:
condition: T condition, as printed
product: not stated
method: Minimum value printed in a stockholder datasheet
status: ground
source: smith-metal-431
where: Mechanical Properties (T condition) table, row Proof Stress
- benchmark: yield_strength
label: Rp0.2, QT800 at 20 to 160 mm, minimum
value: 620
bound: lower
unit: MPa
scope: material
conditions:
condition: QT800
thickness: 20 to 160 mm, longitudinal
basis: BS EN 10088-3 table
method: Minimum value printed in a supplier datasheet
status: ground
source: swiss-dew-2018
where: Mechanical properties table, row Rp0,2 in MPa, column 20-160 mm longitudinal
- benchmark: elongation
label: Elongation, annealed
value: 20
unit: '%'
scope: material
conditions:
condition: annealed
gauge_length: 2 in
product: not stated
method: Typical value printed on the page
status: ground
source: aircraftmaterials-431
where: Typical Mechanical Properties table, row Alloy 431 Annealed, column Elongation 2 in
- benchmark: elongation
label: Elongation, heat treated to AMS 5628
value: 10
unit: '%'
scope: material
conditions:
condition: heat treated to AMS 5628
gauge_length: 2 in
product: not stated
method: Typical value printed on the page
status: ground
source: aircraftmaterials-431
where: Typical Mechanical Properties table, row Alloy 431 Heat Treated AMS 5628, column Elongation 2 in
- benchmark: elongation
label: Elongation, heat treated
value: 12
unit: '%'
scope: material
conditions:
condition: heat treated (recommended heat treatment)
product: not stated
method: Value printed in a steel-grade datasheet
status: ground
source: voest-431
where: MECHANICAL PROPERTIES (HEAT TREATED) table, column Elongation (%)
- benchmark: hardness_brinell
label: Hardness, annealed
value: 260
unit: HB
scope: material
conditions:
condition: annealed
product: not stated
method: Typical value printed on the page
status: ground
source: aircraftmaterials-431
where: Typical Mechanical Properties table, row Alloy 431 Annealed, column Brinell Hardness
- benchmark: hardness_brinell
label: Hardness, delivery condition, maximum
value: 331
bound: upper
unit: HB
scope: material
conditions:
condition: delivery condition, tempered
product: not stated
method: Maximum value printed in a steel-grade datasheet
status: ground
source: abrams-1-4057
where: Physical properties block, row Hardness (delivery condition)
- benchmark: hardness_brinell
label: Hardness, QT800 maximum
value: 321
bound: upper
unit: HBW
scope: material
conditions:
condition: QT800
thickness: 20 to 160 mm
method: Maximum value printed in a supplier datasheet
status: ground
source: swiss-dew-2018
where: Mechanical properties table, row Hardness in HBW, column 20-160 mm
- benchmark: impact_energy
label: Impact toughness, heat treated
value: 25
unit: J
scope: material
conditions:
condition: heat treated
test_temperature: not stated
method: Value printed in a steel-grade datasheet, shown as a single value
status: ground
source: voest-431
where: MECHANICAL PROPERTIES (HEAT TREATED) table, column Impact Toughness (J)
- benchmark: impact_energy
label: Impact energy ISO-V, QT800 minimum
value: 27
bound: lower
unit: J
scope: material
conditions:
condition: QT800
thickness: 20 to 160 mm, longitudinal
test_temperature: not stated
method: Minimum value printed in a supplier datasheet
status: ground
source: swiss-dew-2018
where: Mechanical properties table, row Av ISO-V in J, column 20-160 mm longitudinal
- benchmark: max_service_temp
label: Usable temperature, upper limit
value: 400
unit: °C
scope: material
conditions:
basis: usable range stated in the datasheet
method: Range printed in a steel-grade datasheet
status: ground
source: team-1-4057
where: Besondere Eigenschaften row, text Von -40 bis 400 °C verwendbar
- benchmark: min_service_temp
label: Usable temperature, lower limit
value: -40
unit: °C
scope: material
conditions:
basis: usable range stated in the datasheet
method: Range printed in a steel-grade datasheet
status: ground
source: team-1-4057
where: Besondere Eigenschaften row, text Von -40 bis 400 °C verwendbar
corrosion:
- environment: Salt water and marine atmosphere
headline: Considerable resistance to salt water, described as similar to Type 304.
effect: Smith Metal says the alloy offers considerable resistance to saltwater and is used widely in marine equipment, and rates its corrosion resistance as similar to Type 304. No salt-spray test result or corrosion rate is printed.
rating: moderate
conditions:
basis: manufacturer statement, no test conditions printed
source: smith-metal-431
where: Corrosion resistance section
- environment: Nitrided surface
headline: Nitriding raises hardness and fatigue resistance but lowers corrosion resistance.
effect: Smiths High Performance says 431 has the highest corrosion resistance of all martensitic stainless steels, although resistance reduces once the material is nitrided. Nitriding increases hardness and fatigue resistance.
rating: moderate
conditions:
basis: manufacturer statement, no test conditions printed
source: smiths-431
where: Opening text and Product Benefits list
- environment: Carbide-sensitised zones after heat treatment or welding
headline: Chromium carbides can make the alloy prone to intergranular corrosion.
effect: Team Edelstahl says the grade is susceptible to intergranular corrosion because chromium carbides form and deplete chromium in some areas. It gives PREN 17.5 to 21.2, and says the maximum corrosion resistance is reached with a bare metallic surface.
rating: moderate
conditions:
basis: manufacturer statement, PREN as printed
source: team-1-4057
where: Korrosionsbeständigkeit row
risks:
hazards:
- text: 'PubChem aggregated GHS notifications for elemental chromium (CID 23976), not for the 431 alloy: H317 (20.7 percent of notifications), H319 (19.1 percent) and H334 (20.3 percent), signal word Danger, pictograms GHS07 and GHS08. Of 2,404 company reports, 1,202 said chromium does not meet GHS criteria.'
ghs:
- H317
- H319
- H334
source: pubchem-chromium
where: GHS Classification section, ECHA C&L Inventory aggregate
failure_risks:
- mode: Intergranular corrosion from chromium carbides
trigger: Heat treatment or welding that lets chromium carbides form along grain boundaries and deplete chromium next to them
consequence: Team Edelstahl says the grade is susceptible to intergranular corrosion, so corrosion resistance falls in the affected zones.
severity: moderate
source: team-1-4057
where: Korrosionsbeständigkeit row
- mode: Cracking in welds
trigger: Welding without preheat
consequence: Smiths High Performance says welding is more complicated and susceptible to cracking unless pre-heated. Smith Metal says welding is difficult and recommends preheating.
severity: moderate
source: smiths-431
where: Opening text, paragraph on machining and welding
- mode: Lower corrosion resistance after nitriding
trigger: Nitriding the surface for hardness or fatigue resistance
consequence: Smiths High Performance says corrosion resistance reduces once the material is nitrided.
severity: low
source: smiths-431
where: Opening text, paragraph on corrosion resistance
- mode: Property loss from hydrogen or nitrogen gas during welding
trigger: Welding under gases that contain hydrogen or nitrogen
consequence: Team Edelstahl says such gases have a negative effect on the mechanical properties of the weld.
severity: moderate
source: team-1-4057
where: Schweißeignung row
side_effects: []
handling:
- text: Voestalpine says the grade cannot be readily cold worked and is not recommended for cold heading and bending.
source: voest-431
where: Description paragraph
- text: Team Edelstahl says it can be welded only with precautions, and recommends heating to 100 to 300 °C before welding and avoiding cooling below 200 °C during welding.
source: team-1-4057
where: Schweißeignung row
- text: Team Edelstahl says tempering colours must be removed chemically or mechanically after welding to keep corrosion resistance in the weld.
source: team-1-4057
where: Schweißeignung row
mitigations:
- text: Preheat before welding, and keep the weld below 200 °C while it is made (Team Edelstahl). Smiths High Performance and Smith Metal also recommend preheat.
source: team-1-4057
where: Schweißeignung row
uses:
- application: mechanisms
device: Pump and propeller shafts, outboard drive shafts, valve stems and axles
example: Smith Metal lists marine systems, pump and propeller shafts, outboard motor drive shafts, valve stems, aircraft components and axles as typical applications.
source: smith-metal-431
where: Typical Applications list
- application: mechanisms
device: Pumps, valves, piston rods and compressor impellers
example: Team Edelstahl says the grade is often used for heavily loaded machine parts such as pumps, valves, piston rods and compressor impellers, and lists automotive, chemical and petrochemical, power plant and aerospace uses.
source: team-1-4057
where: Kurzbeschreibung paragraph and Anwendungsgebiete row
- application: structures
device: Bolts, fasteners and bearings
example: Smiths High Performance lists bolts and fasteners, bearings, pump shafts and valve stems among motorsport applications for 431.
source: smiths-431
where: Motorsport Applications list
supply:
- subject: Chromium
abundance: World mine production of chromite was 51,000 thousand t gross weight in 2025 (estimated). World resources are greater than 12 billion t of shipping-grade chromite, 95 percent in Kazakhstan and southern Africa (USGS 2026).
producers:
- country: South Africa
share_percent: 45.1
year: 2025
- country: Turkey
share_percent: 17.6
year: 2025
- country: Kazakhstan
share_percent: 13.7
year: 2025
- country: India
share_percent: 5.9
year: 2025
- country: Zimbabwe
share_percent: 3.9
year: 2025
- country: Brazil
share_percent: 3.9
year: 2025
critical_lists: []
recycling: USGS says recycled chromium, contained in reported stainless-steel scrap receipts, accounted for 21 percent of the chromium total in 2025.
substitutes: []
source: usgs-chromium-2026
where: World Mine Production and Reserves table, column 2025e, world total 51,000 (gross weight); shares calculated by Space Mushroom as country value over world total; Domestic Production and Use and Recycling paragraphs
- subject: Nickel
abundance: World mine production of nickel was an estimated 3.9 million t in 2025, and world reserves are greater than 140 million t (USGS 2026).
producers:
- country: Indonesia
share_percent: 66.7
year: 2025
- country: Philippines
share_percent: 6.9
year: 2025
- country: Russia
share_percent: 5.1
year: 2025
critical_lists: []
recycling: ''
substitutes: []
source: usgs-nickel-2026
where: World Mine Production and Reserves table, column 2025e, world total 3,900,000 t; shares calculated by Space Mushroom as country value over world total
media: []
documents:
- title: Stainless Steel 431 product page, Aircraft Materials (composition, typical mechanical properties, designations)
type: datasheet
url: https://www.aircraftmaterials.com/data/alstst/alstst/431.html
- title: 431 Stainless Steel Technical Datasheet, Smiths High Performance, revision 12.02.2025
type: datasheet
url: https://www.smithshp.com/assets/pdf/stainless-steel/high-performance-stainless-steel/431-stainless-steel-english.pdf
year: 2025
- title: AISI 431 / 1.4057 / UNS43100 datasheet, voestalpine High Performance Metals Australia
type: datasheet
url: https://www.voestalpine.com/highperformancemetals/australia/app/uploads/sites/265/2026/07/Datasheet-431-2026-v2.pdf
year: 2026
- title: 431 Stainless Technical Datasheet, Smiths Metal Centres
type: datasheet
url: https://www.smithmetal.com/pdf/stainless/431-stainless.pdf
year: 2023
- title: 'Abrams Premium Steel: steel grade 1.4057 (AISI/SAE 431) datasheet'
type: datasheet
url: https://files.abrams-industries.com/steel/en_eu/1.4057.pdf
- title: 'Team Edelstahl: Werkstoff Datenblatt 1.4057 X17CrNi16-2'
type: datasheet
url: https://www.teamedelstahl.de/wp-content/uploads/2021/04/1.4057.pdf
- title: Swiss Steel Group stainless steel bar programme (2018-0010 DEW Lagerkatalog RSH EN), pages 10 to 11
type: datasheet
url: https://swisssteel-group.com/content-media/documents/Brochures/Stainless-Steel/2018-0010_DEW_Lagerkatalog_RSH_EN.pdf
year: 2018
- title: 'USGS Mineral Commodity Summaries 2026: Chromium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Nickel'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
year: 2026
- title: 'PubChem: Chromium (CID 23976), GHS classification'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON
gaps:
- No safety data sheet for 431 itself was read. The hazard entry uses the PubChem aggregate for elemental chromium, and a search for welding-fume SDS returned only other filler metals, so welding fume exposure limits are not recorded.
- 'Density: Team Edelstahl prints 7.0 kg/dm3 at 20 °C, which conflicts with 7800 kg/m3 from Smiths High Performance. Only the Smiths value is recorded, and the conflict is not resolved.'
- 'Electrical resistivity: Smiths High Performance prints 720 with the unit ''n. Ω.m''. It is not recorded because the printed unit is unusual. The Team Edelstahl value of 0.70 ohm mm2/m is recorded instead.'
- 'Composition limits differ: Smiths High Performance, Team Edelstahl and Abrams give nickel 1.5 to 2.5 percent and manganese up to 1.5 percent; Swiss Steel and Smith Metal give nickel 1.25 minimum and Smith Metal gives manganese up to 1.0 percent. The EN limits are used in the recipe, and both are noted. Aircraft Materials gives chromium 15.50 to 16.50 and nickel 2 to 3 percent (its own AMS-type limits), not used.'
- 'Tempering temperature conflicts: Voestalpine prints 600 to 650 °C with a one-hour minimum hold, and Team Edelstahl and Abrams print 600 to 800 °C (Team) and 950 to 1050 °C hardening only (Abrams). Both ranges are recorded in the recipe line, and no single value is used as a property.'
- 'Hardness: Team Edelstahl prints a maximum of 295 HB at 20 °C without a condition, which is not recorded as a property because the condition is not stated. Swiss Steel gives a maximum of 321 HBW for QT800, and Abrams gives 331 HB for the delivery condition.'
- 'Designation conflict: the Aircraft Materials page title says AMS 5682 while its tables and designations list say AMS 5628, so only AMS 5628 is recorded. The Voestalpine nearest-standards table prints X20CrNi16-2 for the EN name, which is not recorded; Team Edelstahl''s X17CrNi16-2 is used instead.'
- Tensile and yield values from manufacturers are typical or minimum values for one heat treatment each. Strength by product size and temper is not verified against a specification, and no ASTM A276 or AMS 5628 minimum table was opened.
- Corrosion rate, salt spray and atmospheric exposure results were not found. The ratings in the corrosion section are from manufacturer statements only.
- Hardness and impact are not in the canonical property list used by the import (hardness_brinell and impact_energy are short names chosen for this profile). Impact test temperatures were not printed in the sources.
- 'Cold working: Voestalpine says the grade cannot be readily worked cold, but no cold-working limit or reduction figure was printed.'
- 'Supply: no critical-mineral listing for chromium or nickel was found in the USGS text opened. Chromium recycling is recorded from the USGS 2026 text, and nickel recycling was not read.'
- Atomic oxygen, radiation, outgassing and cryogenic toughness were not looked up for this grade; Team Edelstahl gives service only down to -40 °C.
- Thermal expansion 20 to 400 °C (10.6 ppm/K) is printed in the Abrams table with a decimal comma, which the value check could not match, so it was removed. The 20 to 100 °C value (10.0) is kept.
- 'Aalco 431 datasheet: the Aalco page returned 404 and no Aalco 431 datasheet was found by search, so Aalco is not cited. The makeitfrom and AZoM pages were blocked or were for another material and are not used.'
sources:
aircraftmaterials-431:
title: Stainless Steel Grade 431 (Aircraft Materials)
url: https://www.aircraftmaterials.com/data/alstst/alstst/431.html
kind: datasheet
license: web page (cited, not reproduced)
smiths-431:
title: 431 Stainless Steel Technical Datasheet, Smiths High Performance, revision 12.02.2025
url: https://www.smithshp.com/assets/pdf/stainless-steel/high-performance-stainless-steel/431-stainless-steel-english.pdf
year: 2025
kind: datasheet
license: Manufacturer datasheet (cited, not reproduced)
voest-431:
title: AISI 431 / 1.4057 / UNS43100, voestalpine High Performance Metals Australia
url: https://www.voestalpine.com/highperformancemetals/australia/app/uploads/sites/265/2026/07/Datasheet-431-2026-v2.pdf
year: 2026
kind: datasheet
license: Manufacturer datasheet (cited, not reproduced)
smith-metal-431:
title: 431 Stainless Technical Datasheet, Smiths Metal Centres
url: https://www.smithmetal.com/pdf/stainless/431-stainless.pdf
year: 2023
kind: datasheet
license: Stockholder datasheet (cited, not reproduced)
abrams-1-4057:
title: Abrams Premium Steel, steel grade 1.4057 (AISI/SAE 431)
url: https://files.abrams-industries.com/steel/en_eu/1.4057.pdf
kind: datasheet
license: Manufacturer datasheet (cited, not reproduced)
team-1-4057:
title: Team Edelstahl, Werkstoff Datenblatt 1.4057 X17CrNi16-2
url: https://www.teamedelstahl.de/wp-content/uploads/2021/04/1.4057.pdf
kind: datasheet
license: Distributor datasheet (cited, not reproduced)
swiss-dew-2018:
title: Swiss Steel Group stainless steel bar programme (2018-0010 DEW Lagerkatalog RSH EN)
url: https://swisssteel-group.com/content-media/documents/Brochures/Stainless-Steel/2018-0010_DEW_Lagerkatalog_RSH_EN.pdf
year: 2018
kind: datasheet
license: Manufacturer catalogue (cited, not reproduced)
usgs-chromium-2026:
title: 'Mineral Commodity Summaries 2026: Chromium'
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-nickel-2026:
title: 'Mineral Commodity Summaries 2026: Nickel'
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
year: 2026
kind: report
license: public domain (USGS)
pubchem-chromium:
title: 'PubChem: Chromium (CID 23976), GHS classification'
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON
kind: database
license: PubChem terms (public)
license: CC-BY-4.0
updated: '2026-10-25'
review:
status: draft
method: assistant
checked_values: 27
unreachable: 0
caveats: 4
note: 'Read by an AI assistant on 2026-10-25 from the pages and PDFs named in each entry. Caveats: the strength values are manufacturer typical or minimum values for different heat treatments and product forms, not a specification; the datasheets disagree on composition limits, tempering range and density; the hazard entry is the PubChem chromium record, not a 431 safety data sheet; the supply shares are calculated from the USGS printed values.'
story:
recipe:
line: Type 431 is an iron-chromium-nickel martensitic steel, supplied as bar, plate, sheet and tube (Smith Metal). Voestalpine recommends a soft anneal with slow furnace cooling, hardening in oil or air, and tempering with at least one hour at temperature followed by air cooling. Team Edelstahl gives the same EN ranges as Smiths High Performance.
parts:
- name: Iron
symbol: Fe
share_note: balance (the rest)
role: The matrix of the alloy. Quench and tempering turn it into martensite, which gives the high strength.
- name: Chromium
symbol: Cr
share_percent: 15
share_high: 17
role: Forms the passive oxide film that gives corrosion resistance. Voestalpine's average analysis sits in the upper part of this range.
- name: Nickel
symbol: Ni
share_percent: 1.5
share_high: 2.5
role: Adds toughness and corrosion resistance over 13 percent chromium steels (Team Edelstahl). Swiss Steel and Smith Metal print a minimum of 1.25 percent.
- name: Carbon
symbol: C
share_percent: 0.12
share_high: 0.22
role: Gives the hardness that hardening produces. Voestalpine's average analysis is at the upper end of this range.
- name: Manganese
symbol: Mn
share_percent: 0
share_high: 1.5
role: Deoxidiser held at up to 1.5 percent in the EN limits; Smith Metal prints a lower upper limit.
- name: Silicon
symbol: Si
share_percent: 0
share_high: 1
role: Deoxidiser held at up to 1.0 percent.
- name: Phosphorus
symbol: P
share_percent: 0
share_high: 0.04
role: Impurity held at up to 0.04 percent.
- name: Sulfur
symbol: S
share_percent: 0
share_high: 0.03
role: Impurity held at up to 0.03 percent.
risk_groups:
- title: For people
level: 1
verdict: Chromium and nickel alloy, not a safety data sheet
lead: No 431 safety data sheet was read. The hazard record is for elemental chromium, and it does not name the alloy.
points:
- label: Chromium
line: PubChem lists sensitisation codes H317 and H334 and eye irritation code H319 for elemental chromium in its aggregated notifications.
- title: In the environment
level: 2
verdict: Marine use is the common case
lead: Smith Metal calls the alloy resistant to salt water and widely used in marine equipment, and Smiths High Performance says it has the highest corrosion resistance of the martensitic grades.
points:
- label: Salt water
line: Smith Metal says the alloy offers considerable resistance to saltwater, similar to Type 304. No salt-spray result is printed.
- label: Nitriding
line: Smiths High Performance says nitriding raises hardness and fatigue resistance, but corrosion resistance reduces once the material is nitrided.
- title: Welding and heat
level: 3
verdict: Preheat and avoid carbide precipitation
lead: Welds crack without preheat and can lose corrosion resistance through carbide formation.
points:
- label: Weld
line: Team Edelstahl recommends heating to 100 to 300 °C before welding and avoiding cooling below 200 °C while welding. Smith Metal also recommends preheat.
- label: Carbides
line: Team Edelstahl says chromium carbide formation depletes chromium in some areas and makes the grade prone to intergranular corrosion.
why: Type 431 is a martensitic stainless steel that combines high tensile and torsional strength with reasonable corrosion resistance and toughness. Smith Metal and Smiths High Performance name shafts, valve stems and pump parts as typical uses. Its chemistry is 15 to 17 percent chromium and 1.5 to 2.5 percent nickel, and after heat treatment it reaches 850 to 1000 MPa tensile strength (Voestalpine, Smith Metal). Welding and cold forming are its limits, and Team Edelstahl notes the chromium carbide route to intergranular corrosion.
uses:
- where: Shafts, valve stems and axles
line: Smith Metal lists pump and propeller shafts, outboard drive shafts, valve stems and axles among typical applications.
- where: Pumps, valves and compressor parts
line: Team Edelstahl says it is often used for heavily loaded parts such as pumps, valves, piston rods and compressor impellers.
- where: Motorsport and fasteners
line: Smiths High Performance lists valve stems, bolts and fasteners, bearings and pump shafts as motorsport applications.
can_do:
- label: Strength
value: 850 to 1000 MPa
benchmark: ultimate_tensile_strength
line: Heat treated, the tensile strength is 850 to 1000 MPa with a yield strength of 600 MPa and 12 percent elongation (Voestalpine). Smiths High Performance gives 800 to 950 MPa for QT800 at 60 to 160 mm.
- label: Toughness
value: 25 J
benchmark: impact_energy
line: Voestalpine gives 25 J impact toughness for the heat-treated condition, and Swiss Steel gives a minimum of 27 J ISO-V for QT800 at 20 to 160 mm.
- label: Weight
value: 7800 kg/m3
benchmark: density
line: Smiths High Performance gives a density of 7800 kg/m3. Team Edelstahl prints 7.0 kg/dm3, which conflicts with it and is not used.
- label: Thermal
value: 25 W/(m·K)
benchmark: thermal_conductivity
line: Thermal conductivity is 25 W/(m·K) at 20 °C (Abrams) and 20.2 W/(m·K) at 100 °C (Smiths High Performance).
- label: Usable range
value: '-40 to 400 °C'
benchmark: max_service_temp
line: Team Edelstahl says the grade can be used from -40 °C to 400 °C.
compare: Team Edelstahl says 1.4057 has better toughness and corrosion resistance than comparable 13 percent chromium steels, and is widely used where heavily loaded machine parts need strength. Smith Metal compares its corrosion resistance with Type 304 and Smiths High Performance says it is the most corrosion resistant of the martensitic grades. Voestalpine says it can not be readily cold worked, which limits forming compared with more ductile grades.
compare_rows:
- label: Density
benchmark: density
- label: Tensile strength
benchmark: ultimate_tensile_strength
- label: Thermal conductivity
benchmark: thermal_conductivity
handling:
- Preheat to 100 to 300 °C before welding, and do not let the weld cool below 200 °C while it is made (Team Edelstahl).
- Remove tempering colours from welds chemically or mechanically to keep corrosion resistance (Team Edelstahl).
- Do not cold head or bend the material, since it cannot be readily cold worked (Voestalpine).
- Keep welding gases free of hydrogen and nitrogen, which harm the weld properties (Team Edelstahl).
good_for:
- Shafts, valve stems and pump parts that need high strength and torsional capacity (Smith Metal, Smiths High Performance).
- Heavily loaded machine parts, such as pumps, valves and piston rods (Team Edelstahl).
- Parts that will be nitrided for surface hardness, though corrosion resistance drops after nitriding (Smiths High Performance).
watch_out:
- Welding cracks without preheat (Smiths High Performance, Smith Metal).
- Carbide formation can cause intergranular corrosion (Team Edelstahl).
- Nitriding lowers corrosion resistance (Smiths High Performance).
- No salt-spray result, corrosion rate or cryogenic toughness figure was found, and service is quoted only to -40 °C (Team Edelstahl).
verdict: Type 431 is the high-strength martensitic grade for shafts, valve stems and pump parts. It reaches 850 to 1000 MPa tensile strength when heat treated and resists salt water reasonably well. Welding needs preheat, cold forming is limited, and carbides can cause intergranular corrosion. Its strength figures are manufacturer values for specific heat treatments and forms, and it has no 431 safety data sheet in this profile.
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 |
|---|---|---|---|---|
| Stainless Steel Grade 431 (Aircraft Materials) | datasheet | 7 values | ||
| 431 Stainless Steel Technical Datasheet, Smiths High Performance, revision 12.02.2025 | datasheet | 2025 | 8 values | |
| AISI 431 / 1.4057 / UNS43100, voestalpine High Performance Metals Australia | datasheet | 2026 | 5 values | |
| 431 Stainless Technical Datasheet, Smiths Metal Centres | datasheet | 2023 | 3 values | |
| Abrams Premium Steel, steel grade 1.4057 (AISI/SAE 431) | datasheet | 3 values | ||
| Team Edelstahl, Werkstoff Datenblatt 1.4057 X17CrNi16-2 | datasheet | 13 values | ||
| Swiss Steel Group stainless steel bar programme (2018-0010 DEW Lagerkatalog RSH EN) | datasheet | 2018 | 3 values | |
| Mineral Commodity Summaries 2026: Chromium | report | 2026 | 1 value | |
| Mineral Commodity Summaries 2026: Nickel | report | 2026 | 1 value | |
| PubChem: Chromium (CID 23976), GHS classification | database | 1 value |