Stainless Steel 317LMN
AISI/SAE 317LMN · UNS S31726 · EN 1.4439, X2CrNiMoN17-13-5
317LMN (UNS S31726, 1.4439, X2CrNiMoN17-13-5) is a nitrogen-alloyed, high-molybdenum low-carbon austenitic stainless steel in the 317 family, with nitrogen raising both strength and localized corrosion resistance above 317L and 317LM.
Reference datasheet — 317LMN is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Annealed condition
317LMN tempers and conditions
317LMN is supplied in 4 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault solution annealed (~1050–1120 °C, rapid quench), pickled | Standard supply condition for plate, sheet, bar, pipe and fittings; maximum corrosion resistance and ductility. | 340 | 620 | 45 | 165 HB | — |
As-welded deposit | Reference condition for fabricated vessels; strength is governed by the weld, and over-alloyed filler (e.g. ERNiCrMo-3) is used to match the base metal's pitting resistance. | 350 | 590 | 33 | 180 HB | 2 % IACS |
cold rolled, annealed, pickled and lightly skin-passed sheet | Thin sheet/coil (0.5–6 mm) with smooth 2B finish for tank linings, plate heat exchangers and formed parts. | 355 | 640 | 44 | 175 HB | 2 % IACS |
Cold drawn | Choose for higher strength shafts, fasteners and machined fittings where corrosion resistance of the L+N grade is still needed. | 550 | 760 | 25 | 220 HB | — |
Supply forms, finishes and certifications
Ways 317LMN is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CW-Tube | CW | Supply form |
HRAP | Hot rolled, solution annealed and pickled plate | Surface finish |
What is 317LMN?
317LMN (UNS S31726, 1.4439, X2CrNiMoN17-13-5) is a nitrogen-alloyed, high-molybdenum low-carbon austenitic stainless steel in the 317 family, with nitrogen raising both strength and localized corrosion resistance above 317L and 317LM. Annealed product reaches 340 MPa yield, 620 MPa tensile, 45 % elongation and 165 HB (85 HRB), and is available as hot-rolled annealed and pickled plate, 2B cold-rolled sheet, cold-drawn bar and cold-worked tube. Rated service is to 425 °C, machinability is poor (score 30) and press loads are high, so it is chosen only where 316L pits. Nearest alternatives are 317LM below it and a 6 % Mo superaustenitic above it. 317LMN has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F). 317LMN has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
What is 317LMN used for?
- FGD systems
- chemical process equipment
- offshore hardware
Advantages
- Good corrosion resistance — 80/100, better than 88% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
- Forms and bends easily — 70/100, better than 79% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 77% of stainless steel grades
317LMN properties
Typical room-temperature values for 317LMN-Annealed; bars are the position among stainless steel grades.
Physical3
317LMN has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F).
Mechanical14
317LMN has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
317LMN is rated for continuous service to 425°C (797 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
317LMN conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (80/100), better than 88% of stainless steel grades.
Sustainability4
Producing a kilogram of 317LMN takes about 58 MJ of energy and emits 5.5 kg of CO₂ — more than 66% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
317LMN's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability very good (80/100); formability very good (70/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 317LMN is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 317LMN
Is 317LMN easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, 30–60 % lower speed than 304, heavy feed and copious flood coolant to avoid glazing.
Can 317LMN be welded?
Readily welded by GTAW/GMAW/SMAW without pre- or post-weld heat treatment; use over-alloyed filler (317L/Mo-rich, ERNiCrMo-3/-4) to keep weld-metal PREN at base-metal level, keep heat input low and interpass < 150 °C.
Can 317LMN be formed, bent or molded?
Cold forms well but needs ~40–50 % more press force and larger springback allowance than 316L; hot work 1150–900 °C followed by full solution anneal and quench.
317LMN chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Clow-carbon grade | ≤ 0.03 | 0.02 |
| Si | ≤ 0.75 | 0.4 |
| Mn | ≤ 2 | 1.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0 |
| CrEN 1.4439: 16.5–18.5 | 17 – 20 | 18.5 |
| NiEN 1.4439: 12.5–14.5 | 13.5 – 17.5 | 14.5 |
| Mo | 4 – 5 | 4.3 |
| NEN 1.4439: 0.12–0.22 | 0.1 – 0.2 | 0.15 |
| Cu | ≤ 0.75 | 0.3 |
| Fe | balance |
What surface finishes work on 317LMN?
Pickle and passivate (ASTM A967) or electropolish after welding to restore the passive film; no anodising — mechanical polishing to No.4/mirror is straightforward.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 317LMN in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S31726
- EN / DIN / Werkstoff-Nr.
- 1.4439X2CrNiMoN17-13-5
How much does 317LMN cost?
317LMN is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
317LMN — frequently asked
What is 317LMN used for?
317LMN is typically used for FGD systems, chemical process equipment and offshore hardware. In short: nitrogen-strengthened 317 grade; highest PREN in 317 family; below 6Mo superaustenitics.
What is the yield strength of 317LMN?
317LMN has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 55% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 317LMN easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, 30–60 % lower speed than 304, heavy feed and copious flood coolant to avoid glazing.
Can 317LMN be welded?
Yes — weldability is rated very good (80/100). Readily welded by GTAW/GMAW/SMAW without pre- or post-weld heat treatment; use over-alloyed filler (317L/Mo-rich, ERNiCrMo-3/-4) to keep weld-metal PREN at base-metal level, keep heat input low and interpass < 150 °C.
What surface finishes work on 317LMN?
Pickle and passivate (ASTM A967) or electropolish after welding to restore the passive film; no anodising — mechanical polishing to No.4/mirror is straightforward.
Can 317LMN be formed, bent or molded?
Cold forms well but needs ~40–50 % more press force and larger springback allowance than 316L; hot work 1150–900 °C followed by full solution anneal and quench.
What is the maximum service temperature of 317LMN?
317LMN is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 317LMN Annealed and 317LMN-CD?
Annealed is the default condition — standard supply condition for plate, sheet, bar, pipe and fittings; maximum corrosion resistance and ductility. CD: choose for higher strength shafts, fasteners and machined fittings where corrosion resistance of the L+N grade is still needed. Yield strength is 340 MPa in Annealed versus 550 MPa in CD.
How much does 317LMN cost?
317LMN is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip (S31726) — ASTM International (2023)
- ASTM A182 / A312 / A276 (S31726 forgings, pipe, bar) — ASTM International (2022)
- EN 10088-1/-2 — Stainless steels: X2CrNiMoN17-13-5 (1.4439) — CEN (2014)
- GB/T 24511 / GB/T 4237 (022Cr19Ni13Mo4N ) — SAC (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Outokumpu Steel Grades / Corrosion Handbook (317LMN, 4439) — Outokumpu (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.