431
Data verified431 is a nickel-bearing martensitic stainless that develops the best combination of hardness, toughness and corrosion resistance in the martensitic family. It is used for high-strength shafts and marine hardware.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.20 |
| Si | ≤1.00 |
| Mn | ≤1.00 |
| P | ≤0.040 |
| S | ≤0.030 |
| Cr | 15.00–17.00 |
| Ni | 1.25–2.50 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Hardened & tempered |
| Hardness (hardened) | 35–45 HRC typical |
| Tensile strength | 860–1350 MPa (Q&T) |
| Density | 7.70 g/cm³ |
| Magnetic | Yes |
Heat treatment
Harden 980–1065 °C oil; temper 600–650 °C for the standard high-toughness condition; avoid the 475–560 °C tempering range.
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.4057 |
| aisi | 431 |
| jis | SUS431 |
| gb | 14Cr17Ni2 |
Compare side by side: 431 vs 420
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Pump and propeller shafts, marine hardware, aircraft fittings, high-strength bolts, valve stems.
Processing: Machines in the annealed condition; weldable with care and post-weld temper; through-hardens in larger sections than 410 or 420.
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Ask for a quotationVisit NasteelSource: ASTM A276 / EN 10088 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.