317LMN vs 316L — when is the upgrade worth it?

When chlorides, temperature or crevice geometry push 316L into pitting: 317LMN’s extra molybdenum (4–5% vs 2–3%) and nitrogen give a clear PREN margin for a moderate price step.

Grades · Stainless Steel · 317LMN

317LMN

Data verified

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.

Hardness≤217 HB (annealed)

DIN1.4439

AISIUNS S31726 (317LMN)

CategoryStainless Steel

Chemical composition

Element	Content (%)
C	≤0.030
Si	≤0.75
Mn	≤2.00
P	≤0.045
S	≤0.030
Cr	17.00–20.00
Ni	13.50–17.50
Mo	4.00–5.00
N	0.10–0.20

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Delivery condition	Solution annealed
Hardness	≤217 HB (annealed)
Tensile strength	≥550 MPa
Yield strength	≥240 MPa
Density	8.00 g/cm³
PREN	~35

Heat treatment

Solution anneal 1060–1120 °C, rapid cool (water).

Equivalent grades

Standard	Designation
din	1.4439
aisi	UNS S31726 (317LMN)

Compare side by side: 317LMN vs 317L · 317LMN vs 316L

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: Chemical and pharmaceutical plant, pulp and paper, FGD components, food processing with aggressive cleaning chemicals.

Processing: Welds with matching or over-alloyed fillers using standard austenitic practice; nitrogen raises strength, so forming forces are higher than 317L.

FAQ

317LMN vs 316L — when is the upgrade worth it?: When chlorides, temperature or crevice geometry push 316L into pitting: 317LMN’s extra molybdenum (4–5% vs 2–3%) and nitrogen give a clear PREN margin for a moderate price step.

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Source: ASTM A240 published ranges (UNS S31726) · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.