317LMN vs 317L
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
317LMN
Stainless Steel
317LMN is the low-carbon, nitrogen-bearing version of the 317 family with 4–5% molybdenum. It sits between 317L and the 6% Mo super-austenitics: clearly better pitting and crevice resistance than 316L at a lower alloy cost than 254 SMO.
Standards: DIN 1.4439 · AISI UNS S31726 (317LMN)
317L
Stainless Steel
317L is the low-carbon version of 317, with 3–4% molybdenum for welded equipment in hot chloride and acid service beyond the capability of 316L. Its PREN of about 30 bridges the gap to super-austenitic grades.
Standards: DIN 1.4438 · AISI 317L · JIS SUS317L · GB 022Cr19Ni13Mo3
Chemical composition compared (%)
| Element | 317LMN | 317L |
|---|---|---|
| C | ≤0.030 | ≤0.030 |
| Si | ≤0.75 | ≤0.75 |
| Mn | ≤2.00 | ≤2.00 |
| P | ≤0.045 | ≤0.045 |
| S | ≤0.030 | ≤0.030 |
| Cr | 17.00–20.00 | 18.00–20.00 |
| Ni | 13.50–17.50 | 11.00–15.00 |
| Mo | 4.00–5.00 | 3.00–4.00 |
| N | 0.10–0.20 | ≤0.10 |
Properties compared
| Property | 317LMN | 317L |
|---|---|---|
| Delivery condition | Solution annealed | Annealed |
| Hardness | ≤217 HB (annealed) | ≤217 HB (annealed) |
| Tensile strength | ≥550 MPa | 515–690 MPa |
| Yield strength | ≥240 MPa | — |
| Density | 8.00 g/cm³ | 7.90 g/cm³ |
| PREN | ~35 | — |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: 317LMN · 317L. Substitution decisions for certified parts stay with the design authority.