- Grade / Alloy
- 1.4598
- EN / W.Nr.
- 1.4598X2CrNiMoCuS17-10-2
- AISI / SAE
- —
- UNS
- —
- Other names
- 316L+S+Cu
- Family
- Austenitic
Chemical composition
Chemical composition
Composition limitsComposition limits for long products within EN 10088-3:2014.
| Element | Content (% by mass) |
|---|---|
| CCarbon | ≤ 0.03 |
| SiSilicon | ≤ 1 |
| MnManganese | ≤ 2 |
| PPhosphorus | ≤ 0.045 |
| SSulfur | 0.1–0.2 |
| NNitrogen | ≤ 0.1 |
| CrChromium | 16.5–18.5 |
| NiNickel | 10–13 |
| MoMolybdenum | 2–2.5 |
| CuCopper | 1.3–1.8 |
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.
Why is 1.4598 a separate grade?
1.4598 combines a molybdenum-bearing composition related to the 316 family with sulfur and copper additions for machining. This distinction matters in precision components made from small-diameter bar. Sulfur assists chip breaking and copper contributes to machining behaviour. The material is therefore not treated as identical to standard 316L.
Use in precision mechanical components
Watch and precision-mechanism parts, small connections and turned components are among its applications. The purpose is not merely easier cutting, but a stainless option suited to repeated small geometries. Molybdenum distinguishes it from the molybdenum-free 303 family. Surface finish and dimensional precision are important features of these components.
Machinability and corrosion resistance
The sulfur addition changes corrosion behaviour as well as machinability. Corrosion resistance should not automatically be equated with a low-sulfur 316L or 1.4435. Welded structures are not the primary application. Commercial descriptions such as 316F or 316L+S+Cu may be encountered, but the EN number identifies the composition more clearly.
Reference range for solution-annealed long products
The table applies to the stated +AT long-product conditions and sections up to 160 mm under EN 10088-3:2014. Cold-worked small bars may have different strength. Elongation refers to longitudinal testing.
| Property | Value |
|---|---|
| Tensile strength Rm | 500–700 MPa |
| Proof strength Rp0.2 | ≥ 200 MPa |
| Elongation A | ≥ 40% |
Typical application areas
Precision turned parts, fittings, small mechanical components.
Product and cutting options
Relevant product forms for this material are listed below. Availability varies with grade and dimensions.