Stainless Steel S31727
UNS S31727
S31727 is a nitrogen-enhanced, high-molybdenum austenitic stainless in the 317LMN family, where nitrogen raises strength and the Mo level lifts pitting and crevice corrosion resistance in aggressive process environments.
Reference datasheet — S31727 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
S31727 tempers and conditions
S31727 is supplied in 2 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault solution annealed (~1100–1150 °C) and rapidly quenched | The only condition supplied for corrosion service — plate, sheet, welded/seamless pipe and tube. | 320 | 620 | 48 | 180 HB | — |
Cold drawn | Choose for bar stock and small-diameter tube needing tighter tolerance, better surface and higher yield strength; corrosion performance is essentially unchanged but residual stress raises SCC sensitivity. | 550 | 760 | 30 | 22 HRC | 2 % IACS |
What is S31727?
S31727 is a nitrogen-enhanced, high-molybdenum austenitic stainless in the 317LMN family, where nitrogen raises strength and the Mo level lifts pitting and crevice corrosion resistance in aggressive process environments. Annealed material provides 320 MPa yield, 620 MPa tensile, 48 % elongation and about 180 HB (88 HRB), with a maximum service temperature near 800 °C; usual forms are annealed plate, sheet and cold-drawn bar. It machines gummy (formability score 65, weldability 75), needs more press force than 317L and is a specialty melt with long lead times; 317LMN or a 6 Mo austenitic are the nearest alternatives. S31727 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). S31727 has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of stainless steel grades. Elongation at break is 48% and the elastic modulus is 195 GPa (28.3 Msi).
What is S31727 used for?
- Pulp and paper processing equipment
- Chemical process piping
- Bleach and liquor tank internals
- Heat exchanger tubing and tube sheets
- Flue-gas scrubber components
- Seawater and brine handling parts
- Valve and pump wetted components
Advantages
- Ductile — tolerates forming and impact — 48%, better than 85% 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
S31727 properties
Typical room-temperature values for S31727-Annealed; bars are the position among stainless steel grades.
Physical3
S31727 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
S31727 has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of stainless steel grades. Elongation at break is 48% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
S31727 is rated for continuous service to 800°C (1,472 °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
S31727 conducts electricity at 2 % IACS, worse than 77% 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 S31727 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
S31727's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability very good (75/100); formability good (65/100).
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. S31727 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S31727
Is S31727 easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, heavy positive feed to cut under the hardened layer, 20–35 % lower speed than 316L and copious high-pressure coolant.
Can S31727 be welded?
Readily welded by GTAW/GMAW/SMAW without preheat or PWHT; use over-alloyed filler (ERNiCrMo-3 / 625 or 317L-Mo-rich) to compensate Mo segregation, keep interpass <150 °C and heat input low, then pickle/passivate.
Can S31727 be formed, bent or molded?
Cold forms like 317L but needs ~20–30 % more force and generous bend radii due to high work-hardening; hot work 1150–900 °C followed by full solution anneal and quench.
S31727 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 for as-welded IGC resistance | ≤ 0.03 | 0.02 |
| Mn | ≤ 1 | 0.8 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cr | 17.5 – 19 | 18.3 |
| Ni | 14.5 – 16.5 | 15.5 |
| Mopitting/crevice resistance | 3.8 – 4.5 | 4.1 |
| Cuimproves resistance to reducing acids | 2.8 – 4 | 3.4 |
| Naustenite stabiliser, raises strength and PREN | 0.15 – 0.21 | 0.18 |
| Fe | balance |
What surface finishes work on S31727?
Pickle in HNO3-HF and passivate after hot work or welding to restore the passive film; electropolishing gives the best crevice-corrosion performance; not anodizable.
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
How much does S31727 cost?
S31727 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.
S31727 — frequently asked
What is S31727 used for?
S31727 is typically used for pulp and paper processing equipment, chemical process piping, bleach and liquor tank internals, heat exchanger tubing and tube sheets, flue-gas scrubber components and seawater and brine handling parts. In short: nitrogen-strengthened 317LMN type; high-Mo crevice resistance; demanding to machine.
What is the yield strength of S31727?
S31727 has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of stainless steel grades. Strength varies by condition: see the 2 listed tempers.
Is S31727 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake coated carbide, heavy positive feed to cut under the hardened layer, 20–35 % lower speed than 316L and copious high-pressure coolant.
Can S31727 be welded?
Yes — weldability is rated very good (75/100). Readily welded by GTAW/GMAW/SMAW without preheat or PWHT; use over-alloyed filler (ERNiCrMo-3 / 625 or 317L-Mo-rich) to compensate Mo segregation, keep interpass <150 °C and heat input low, then pickle/passivate.
What surface finishes work on S31727?
Pickle in HNO3-HF and passivate after hot work or welding to restore the passive film; electropolishing gives the best crevice-corrosion performance; not anodizable.
Can S31727 be formed, bent or molded?
Cold forms like 317L but needs ~20–30 % more force and generous bend radii due to high work-hardening; hot work 1150–900 °C followed by full solution anneal and quench.
What is the maximum service temperature of S31727?
S31727 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 S31727 Annealed and S31727-CD?
Annealed is the default condition — the only condition supplied for corrosion service — plate, sheet, welded/seamless pipe and tube. CD: choose for bar stock and small-diameter tube needing tighter tolerance, better surface and higher yield strength; corrosion performance is essentially unchanged but residual stress raises SCC sensitivity. Yield strength is 320 MPa in Annealed versus 550 MPa in CD.
How much does S31727 cost?
S31727 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
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip — ASTM International (2023)
- ASTM A312/A312M — Seamless and Welded Austenitic Stainless Steel Pipes — ASTM International (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- High-molybdenum nitrogen-enhanced austenitic stainless (317LMN class) datasheets — Outokumpu / Sandvik (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.