PH grades / UNS S13800
13-8 Mo is a premium-melted martensitic precipitation-hardening stainless steel offering very high strength with better toughness and transverse properties than 17-4 PH.
- UNS S13800
- W.Nr. 1.4534
- Spec ASTM A564 / A693
- Density 7.76 g/cm³
Also known as / equivalents
| System | Designation |
|---|---|
| UNS | S13800 |
| W.Nr. | 1.4534 |
| EN | X3CrNiMoAl13-8-2 |
| Also known as | PH 13-8 Mo, XM-13, 1.4534 |
Chemical composition
| Element | Min % | Max % |
|---|---|---|
| C | — | 0.05 |
| Mn | — | 0.20 |
| P | — | 0.010 |
| S | — | 0.008 |
| Si | — | 0.10 |
| Cr | 12.25 | 13.25 |
| Ni | 7.5 | 8.5 |
| Mo | 2.0 | 2.5 |
| Al | 0.90 | 1.35 |
| N | — | 0.01 |
| Fe | Bal. | — |
Heat treatment / condition
| Condition | Tensile, MPa | Yield 0.2%, MPa | Elongation, % | Hardness, HRC |
|---|---|---|---|---|
| H950 | 1515 | 1410 | 10 | 45 min |
| H1000 | 1415 | 1310 | 10 | 43 min |
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.76 g/cm³ | 0.280 lb/in³ |
| Magnetic response | Magnetic | — |
Available forms & specifications
| Form | Specification | Size range |
|---|---|---|
| Sheets, plates & strip | ASTM A693 | 0.3 mm – 6 mm |
| Bars & wire | ASTM A564 / ASME SA564 | 3 mm – 500 mm |
| Forgings | ASTM A705 / ASME SA705 | 1/2" – 48" NB (larger on request) |
Corrosion & temperature resistance
Corrosion resistance is broadly comparable to 304 in most environments. Higher ageing temperatures (H1100, H1150, H1150D/M) lower strength but improve toughness and resistance to stress-corrosion cracking.
Applications
13-8 Mo: Aerospace structures, landing gear, nuclear. Pump and valve shafts, oilfield and aerospace components, gears, fasteners, moulds and high-strength fittings.
13-8 Mo vs 17-4 PH
| 13-8 Mo | 17-4 PH | |
|---|---|---|
| UNS | S13800 | S17400 |
| Key property | Very high strength, good toughness | High strength + stainless corrosion resistance |
| Typical use | Aerospace structures, landing gear, nuclear | Shafts, valve parts, aerospace, fasteners |
| Cr (wt %) | 12.25–13.25 | 15.0–17.5 |
| Ni (wt %) | 7.5–8.5 | 3.0–5.0 |
| Mo (wt %) | 2.0–2.5 | — |
| C (wt %) | ≤ 0.05 | ≤ 0.07 |
| Tensile / yield (min, MPa) | — | — |
Frequently asked questions
What is the UNS number of 13-8 Mo?
13-8 Mo is designated UNS S13800 (W.Nr. 1.4534, EN X3CrNiMoAl13-8-2).
What is 13-8 Mo used for?
Very high strength, good toughness. Typical uses: aerospace structures, landing gear, nuclear.
Is 13-8 Mo magnetic?
Magnetic.
In which forms can I buy 13-8 Mo from Rajkamal Metals?
Coils & Strips, Sheets & Plates, Round Bars & Rods, Fasteners. Sizes as per standard; other sizes on request.
Do you supply a Mill Test Certificate with 13-8 Mo?
Yes. Actual values are given in the Mill Test Certificate (EN 10204 3.1) supplied with each order.
What is the difference between 13-8 Mo and 17-4 PH?
13-8 Mo: very high strength, good toughness. 17-4 PH: high strength + stainless corrosion resistance. See the comparison table on this page.
Last updated: 30 October 2026. Grade names identify the supply range; designations are not engineering equivalents. Availability, make, origin and documentation are confirmed at quotation.
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