- Grade / Alloy
- 1.4938
- EN / W.Nr.
- 1.4938X12CrNiMoV12-3
- AISI / SAE
- —
- UNS
- —
- Family
- Martensitic
Chemical composition
Chemical composition
Composition limitsComposition limits for aerospace bars within EN 4825:2021, not merged with related AMS/SEL designations.
| Element | Content (% by mass) |
|---|---|
| CCarbon | 0.08–0.15 |
| SiSilicon | ≤ 0.5 |
| MnManganese | 0.5–0.9 |
| PPhosphorus | ≤ 0.025 |
| SSulfur | ≤ 0.015 |
| CrChromium | 11–12.5 |
| MoMolybdenum | 1.5–2 |
| NiNickel | 2–3 |
| VVanadium | 0.25–0.4 |
| NNitrogen | 0.02–0.04 |
| FeIron | Balance |
Values describe the grade, not the analysis of a specific batch. The applicable product specification and material certificate determine acceptance. A dash does not mean zero.
Which properties does 1.4938 combine?
Grade 1.4938 combines high strength with the corrosion and oxidation behaviour of a chromium steel. Its nickel-, molybdenum- and vanadium-bearing composition differs from the general 420 family. Aerospace connections and loaded mechanical components are familiar applications. The stainless designation does not imply resistance to the same fluids and environments as 316L: the two families offer different strengths.
Bars within EN 4825
EN 4825:2021 defines hardened and tempered aerospace bars of X12CrNiMoV12-3 / 1.4938 with an equivalent diameter up to 150 mm. The specification combines a particular product form, metallurgical route and delivery condition. A bar sharing the chemical designation does not automatically meet every requirement. The room-temperature values below apply to that defined scope.
| Property | EN 4825 scope |
|---|---|
| Product / condition | Bar; hardened and tempered |
| Equivalent diameter De | ≤ 150 mm |
| Tensile strength Rm | 900–1,100 MPa |
| Proof strength Rp0.2 | ≥ 750 MPa |
| Elongation A | ≥ 14%; ≥ 10% for cold-worked material |
Why related aerospace designations stay separate
Related aerospace families may be listed with names such as Jethete and designations including 1.4933, 1.4938, 1.4939 or S64152. Their appearance together in a producer catalogue does not establish identical chemical limits. Nitrogen and sulfur limits, for example, can differ with the product specification. This page follows 1.4938 within EN 4825:2021, without combining analyses of related materials or assigning an unverified exact UNS equivalent.
Its role in mechanical components
The hardened and tempered structure is central to the strength of this grade. An annealed starting product and a bar in its final use condition do not have identical mechanical properties. Machined connections and specialised mechanical components are more representative applications than general welded tanks or piping systems. Nor is one service-temperature limit assigned to every component: load and product specification remain part of that assessment.
Typical application areas
Aerospace connections, high-strength mechanical parts, turbine components.
Product and cutting options
Relevant product forms for this material are listed below. Availability varies with grade and dimensions.