Data completeness: partial. Last verified 19 August 2026.
Designations
| Common name | 17-7 PH |
| UNS | S17700 |
| EN number | 1.4568 |
| Class | Precipitation hardening stainless steel |
| Specified by | ASTM A693/A693M |
17-7 PH is the semi-austenitic precipitation hardening grade: aluminium-bearing, austenitic and formable as delivered, then transformed to martensite and aged to reach its strength. That sequence is the point — it can be pressed, rolled or drawn into shape while soft and hardened afterwards, which a martensitic grade cannot. The datasheet consulted names one row “heat treated” and leaves the others without a condition, so this page carries both and says which is which.
Properties, with what each one rests on
| Property | Value | Unit | Condition | Evidence | Source | Retrieved |
|---|---|---|---|---|---|---|
| Proof strength Rp0.2, typical | 210 | MPa | wire rod; heat treatment condition not stated by the source | E3 | Outokumpu Dura range datasheet — martensitic and precipitation hardening stainless steels | 2026-08-20 |
| Proof strength Rp0.2, typical (heat treated) | 330 | MPa | hot rolled, heat treated | E3 | Outokumpu Dura range datasheet — martensitic and precipitation hardening stainless steels | 2026-08-20 |
| Tensile strength Rm, typical | 700 | MPa | wire rod; heat treatment condition not stated by the source | E3 | Outokumpu Dura range datasheet — martensitic and precipitation hardening stainless steels | 2026-08-20 |
| Elongation A, typical | 50 | % | wire rod; heat treatment condition not stated by the source | E3 | Outokumpu Dura range datasheet — martensitic and precipitation hardening stainless steels | 2026-08-20 |
| Density | 7.8 | g/cm³ | 20 °C | E3 | Outokumpu Dura range datasheet — martensitic and precipitation hardening stainless steels | 2026-08-20 |
| Modulus of elasticity | 200 | GPa | 20 °C | E3 | Outokumpu Dura range datasheet — martensitic and precipitation hardening stainless steels | 2026-08-20 |
| Thermal conductivity | 16 | W/(m·K) | 20 °C | E3 | Outokumpu Dura range datasheet — martensitic and precipitation hardening stainless steels | 2026-08-20 |
| Condition codes and the properties that go with them | not established | — | — | — | the datasheet gives one row marked heat treated without saying which treatment, and none for the standard aged conditions | — |
| Specified minima per condition | not established | — | — | — | these live in ASTM A693, which was not opened; the datasheet states its own figures are typical values | — |
| Hardness | not established | — | — | — | the hardness column is empty for every grade in the datasheet consulted | — |
| PREN | not established | — | — | — | the Dura datasheet prints no PRE column, and importing a formula from a different datasheet would import a method this document does not apply | — |
7 sourced values, 4 gaps named. Publishing the gaps is more useful than filling them from an aggregator that does not say where its numbers came from. The routes to filling them are the standard itself, a mill datasheet, or a mill certificate for your actual heat — which supersedes both at E5.
Where the numbers come from
Proof strength Rp0.2, typical. Low, and that is the delivered condition rather than a weakness — the alloy is sold soft so it can be formed. The row below shows what the same alloy does once treated.
Proof strength Rp0.2, typical (heat treated). This is the only row in the whole Dura table that names a condition at all, and even here “heat treated” is not a condition code — it does not say which treatment. The published strengths for this alloy in its standard aged conditions are far above both figures on this page, which is the clearest possible warning about what a datasheet typical value is and is not.
Elongation A, typical. The highest elongation in this data set, higher than any austenitic here, and it is the formability that the whole alloy design exists to preserve.
Why we do not just copy an aggregator. Because then this page would be a worse copy of MatWeb with no way for you to tell which rows to trust, and the one thing we have that MatWeb does not is the evidence column. Our coverage and its limits.
What 17-7 PH is usually chosen for
Formed springs, clips, diaphragms, bellows and thin strip parts that must be shaped first and strong afterwards. Aerospace and instrument work uses it for exactly that sequence. Where a part could be made from hardened martensitic stock but cannot be formed in that state, this is the alloy that solves the manufacturing problem rather than the service problem.
And what it is usually rejected for
Process control and corrosion. The transformation sequence needs accurate temperature control through several steps, and getting it wrong leaves retained austenite and unpredictable properties; that is a real risk in a small shop. Its corrosion resistance is roughly that of 410 — below 304, well below 316L — so it is a manufacturing choice, not an environmental one.
The number to be more careful with than any of the above is the difference between a specified minimum and a typical value — a floor the standard guarantees, versus what a supplier’s production usually does. The full version, and the most expensive routine mistake in material data.
Compare
What this page does not cover
- The condition behind every number, which for a precipitation hardening alloy is the specification.
- No specified minima. Everything here is a mill typical value and cannot be used as a design allowable.
- No properties for the standard aged conditions, which are the ones a drawing calls out.
- No hardness values.
- No corrosion data.
Generated from data/materials/17-7ph.yaml. Regenerate rather than editing this file by hand — edits here are lost on the next build.