Stainless Steel ER317
UNS S31780
ER317 is a higher-molybdenum austenitic bare wire (UNS S31780) that lifts corrosion resistance above 316-type filler in aggressive chemical media, particularly sulfur-bearing and chloride process streams.
Reference datasheet — ER317 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 AW condition
ER317 tempers and conditions
ER317 is supplied in 3 conditions, soft to hard. AW is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution Annealed weld metal | Choose when the fabricated assembly is post-weld solution annealed to dissolve carbides and relieve residual stress; strength drops, ductility and corrosion resistance rise. | 275 | 560 | 48 | 160 HB | 2.3 % IACS |
As Welded | Pick when depositing ER317 by SAW on heavy plate; slightly lower strength and ferrite due to higher heat input and flux interaction. | 375 | 570 | 35 | 170 HB | 2.2 % IACS |
AWDefault As-welded deposit | Default condition: undiluted deposit from ER317 wire used with argon-based shielding, no post-weld heat treatment. | 400 | 600 | 38 | 180 HB | 2.2 % IACS |
Supply forms, finishes and certifications
Ways ER317 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
WIRE-CD | Bare wire, cold drawn / bright annealed spool or cut length | Supply form |
What is ER317?
ER317 is a higher-molybdenum austenitic bare wire (UNS S31780) that lifts corrosion resistance above 316-type filler in aggressive chemical media, particularly sulfur-bearing and chloride process streams. It is used for pulp and paper digesters and sulfuric or sulfite process equipment, supplied as cold-drawn spooled wire, TIG rod and SAW wire. As-welded deposits give about 400 MPa yield, 600 MPa tensile, 38% elongation and 180 HB (88 HRB), with service to 800 °C and a corrosion rating of 72. It costs more and is stocked less widely than ER316L, which remains the default where the extra molybdenum is not needed. ER317 has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,370°C (2,498 °F). ER317 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 57% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 195 GPa (28.3 Msi).
What is ER317 used for?
- Pulp and paper digester welds
- Sulfuric and sulfite process equipment
- Chemical reactor and tank seams
- Flue gas desulfurization components
- Bleach plant piping and vessels
- Overlay of carbon steel in high-chloride service
- Heat exchanger tube-to-tubesheet welds
Advantages
- Readily welded — 88/100, better than 91% of stainless steel grades
ER317 properties
Typical room-temperature values for ER317-AW; bars are the position among stainless steel grades.
Physical3
ER317 has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical16
ER317 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 57% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
ER317 is rated for continuous service to 800°C (1,472 °F). It conducts heat at 14.5 W/m·K (8.38 BTU/hr·ft·°F), worse than 72% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
ER317 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 73% of stainless steel grades.
Sustainability4
Producing a kilogram of ER317 takes about 58 MJ of energy and emits 4.6 kg of CO₂ — more than 66% of stainless steel grades. Typical recycled content is 55%.
Manufacturability6
ER317's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability excellent (88/100); formability good (60/100).
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. ER317 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ER317
Is ER317 easy to machine?
Weld deposits machine like 317/316 — slow speeds, sharp positive-rake carbide, heavy rigid setup and flood coolant to fight work hardening and gumminess.
Can ER317 be welded?
Run with 98Ar/2%O₂ or Ar-He for GMAW and pure Ar for GTAW; keep interpass below ~150 °C and heat input low to preserve 2–8 FN ferrite and avoid carbide precipitation.
Can ER317 be formed, bent or molded?
Supplied as cold-drawn wire; the deposit itself is highly ductile and cold-formable but work-hardens rapidly, so plan generous bend radii.
ER317 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 |
|---|---|---|
| Cnon-L grade; use ER317L for sensitization-critical service | ≤ 0.08 | 0.05 |
| Cr | 18.5 – 20.5 | 19.5 |
| Ni | 13 – 15 | 14 |
| Mokey addition for pitting resistance | 3 – 4 | 3.5 |
| Mn | 1 – 2.5 | 1.7 |
| Si | 0.3 – 0.65 | 0.45 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cu | ≤ 0.75 | 0.2 |
| Fe | balance |
What surface finishes work on ER317?
Pickle and passivate (nitric or nitric-HF) or mechanically blend the weld to restore the passive film — leaving heat tint sharply reduces the Mo-based pitting benefit.
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 ER317 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S31780
How much does ER317 cost?
ER317 is a high-cost stainless steel ($$$$), pricier than about 78% 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.
ER317 — frequently asked
What is ER317 used for?
ER317 is typically used for pulp and paper digester welds, sulfuric and sulfite process equipment, chemical reactor and tank seams, flue gas desulfurization components, bleach plant piping and vessels and overlay of carbon steel in high-chloride service. In short: higher Mo than 316; sulfite and chloride service; premium-corrosion austenitic filler.
What is the yield strength of ER317?
ER317 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 57% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is ER317 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Weld deposits machine like 317/316 — slow speeds, sharp positive-rake carbide, heavy rigid setup and flood coolant to fight work hardening and gumminess.
Can ER317 be welded?
Yes — weldability is rated excellent (88/100). Run with 98Ar/2%O₂ or Ar-He for GMAW and pure Ar for GTAW; keep interpass below ~150 °C and heat input low to preserve 2–8 FN ferrite and avoid carbide precipitation.
What surface finishes work on ER317?
Pickle and passivate (nitric or nitric-HF) or mechanically blend the weld to restore the passive film — leaving heat tint sharply reduces the Mo-based pitting benefit.
Can ER317 be formed, bent or molded?
Supplied as cold-drawn wire; the deposit itself is highly ductile and cold-formable but work-hardens rapidly, so plan generous bend radii.
What is the maximum service temperature of ER317?
ER317 is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ER317-AW and ER317-SA?
AW is the default condition — default condition: undiluted deposit from ER317 wire used with argon-based shielding, no post-weld heat treatment. SA: choose when the fabricated assembly is post-weld solution annealed to dissolve carbides and relieve residual stress; strength drops, ductility and corrosion resistance rise. Yield strength is 400 MPa in AW versus 275 MPa in SA.
How much does ER317 cost?
ER317 is a high-cost stainless steel ($$$$), pricier than about 78% 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
- AWS A5.9/A5.9M — Bare Stainless Steel Welding Electrodes and Rods — American Welding Society (2017)
- ASTM A276 / UNS S31780 designation listing — ASTM / SAE-ASTM Unified Numbering System (2019)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (stainless filler metals) — ASM International (1993)
- ASM Handbook Vol.1 — Properties of Wrought Stainless Steels — ASM International (1990)
- Stainless filler metal datasheets, ER317/ER317L — Lincoln Electric / voestalpine Böhler Welding (2022)
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.