Stainless Steel S32950
UNS S32950
UNS S32950 (7-Mo Plus) is a duplex stainless with molybdenum content between 2205 and the super duplex grades, giving 560 MPa yield, 800 MPa tensile, 27 % elongation and about 260 HB (26 HRC) in the annealed condition.
Reference datasheet — S32950 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
S32950 tempers and conditions
S32950 is supplied in 5 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged and Solution Annealed | Flanges, valve bodies and fittings; requires post-forge solution anneal and quench to restore phase balance. | 555 | 790 | 25 | 26 HRC | 2.2 % IACS |
AnnealedDefault Solution Annealed (≈1010–1120 °C, rapid quench) | Standard supply condition for plate, bar, tube and fittings; best corrosion resistance and toughness. | 560 | 800 | 27 | 26 HRC | 2.2 % IACS |
As-welded deposit | Reference condition for weld-joint design; over-alloyed filler (e.g. ER2209/25.10.4L) keeps austenite balance. | 560 | 780 | 22 | 27 HRC | 2.2 % IACS |
Cold drawn | Choose for shafts, fasteners and pump parts needing higher yield and tighter tolerance than annealed bar. | 700 | 880 | 20 | 31 HRC | 2.2 % IACS |
Cold worked | Springs, clamps and wire products where maximum strength outweighs ductility and toughness. | 830 | 1,000 | 14 | 35 HRC | 2.2 % IACS |
Supply forms, finishes and certifications
Ways S32950 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
TUBE-SA | Solution Annealed Tube/Pipe | Supply form |
CRA | Cold Rolled, Annealed Sheet/Strip | Surface finish |
HRAP | Hot Rolled, Annealed and Pickled Plate | Surface finish |
What is S32950?
UNS S32950 (7-Mo Plus) is a duplex stainless with molybdenum content between 2205 and the super duplex grades, giving 560 MPa yield, 800 MPa tensile, 27 % elongation and about 260 HB (26 HRC) in the annealed condition. It is specified for pressure vessels, tubing, plate and forgings that need more strength and chloride resistance than 2205 without super duplex cost. Like all duplex grades it is limited to roughly 300 °C service, requires controlled heat input with solution annealing after hot work, and is harder to machine than 316L; 2205 is the cheaper alternative and S32750 the step up. S32950 has a density of 7.74 g/cm³ (0.28 lb/in³), lighter than 72% of stainless steel grades. It melts at 1,385°C (2,525 °F). S32950 has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
What is S32950 used for?
- pressure vessels
- heat exchangers
- chemical processing equipment
Advantages
- High strength — 560 MPa (81.2 ksi), better than 85% of stainless steel grades
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
S32950 properties
Typical room-temperature values for S32950-Annealed; bars are the position among stainless steel grades.
Physical3
S32950 has a density of 7.74 g/cm³ (0.28 lb/in³), lighter than 72% of stainless steel grades. It melts at 1,385°C (2,525 °F).
Mechanical17
S32950 has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S32950 is rated for continuous service to 300°C (572 °F). It conducts heat at 15.5 W/m·K (8.96 BTU/hr·ft·°F), better than 53% of stainless steel grades. Thermal expansion is 12.8 µm/m·K (7.11 µin/in·°F).
Electrical3
S32950 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 84% of stainless steel grades.
Sustainability4
Producing a kilogram of S32950 takes about 62 MJ of energy and emits 4.6 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 65%.
Manufacturability7
S32950's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability very good (70/100); formability fair (45/100).
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. S32950 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S32950
Is S32950 easy to machine?
Machines like 2205 but tougher: use rigid setups, positive-rake carbide, 60–100 m/min surface speed, heavy feeds to cut through the work-hardened layer, and copious coolant.
Can S32950 be welded?
Readily welded by GTAW/GMAW/SMAW with over-alloyed 2209/25.10.4L filler, no preheat, low-to-moderate heat input (≈0.5–2.0 kJ/mm), interpass below 150 °C, Ar+N₂ backing; avoid PWHT unless a full solution anneal and quench is possible.
Can S32950 be formed, bent or molded?
Cold form with roughly twice the force of 316L and allow for high springback; hot work 950–1150 °C followed by mandatory solution anneal and rapid quench.
S32950 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 |
|---|---|---|
| C | ≤ 0.03 | 0.02 |
| Si | ≤ 0.6 | 0.4 |
| Mn | ≤ 2 | 1 |
| P | ≤ 0.04 | |
| S | ≤ 0.01 | |
| Cr | 26 – 29 | 27.5 |
| Ni | 3.5 – 5.2 | 4.3 |
| Mo | 1 – 2.5 | 1.7 |
| N | 0.15 – 0.35 | 0.25 |
| Febalance, ≈64–66 % | balance |
What surface finishes work on S32950?
Pickle in HNO₃/HF and passivate per ASTM A380/A967 to restore the chromium oxide film; can be mechanically ground or polished, 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
Equivalent designations
Standards and trade names that resolve to Stainless Steel S32950 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- 7-Mo Plus
How much does S32950 cost?
S32950 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.
S32950 — frequently asked
What is S32950 used for?
S32950 is typically used for pressure vessels, heat exchangers and chemical processing equipment. In short: between 2205 and super duplex; higher chloride resistance than 2205; 560 MPa yield in annealed plate.
What is the yield strength of S32950?
S32950 has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 85% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is S32950 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Machines like 2205 but tougher: use rigid setups, positive-rake carbide, 60–100 m/min surface speed, heavy feeds to cut through the work-hardened layer, and copious coolant.
Can S32950 be welded?
Yes — weldability is rated very good (70/100). Readily welded by GTAW/GMAW/SMAW with over-alloyed 2209/25.10.4L filler, no preheat, low-to-moderate heat input (≈0.5–2.0 kJ/mm), interpass below 150 °C, Ar+N₂ backing; avoid PWHT unless a full solution anneal and quench is possible.
What surface finishes work on S32950?
Pickle in HNO₃/HF and passivate per ASTM A380/A967 to restore the chromium oxide film; can be mechanically ground or polished, not anodizable.
Can S32950 be formed, bent or molded?
Cold form with roughly twice the force of 316L and allow for high springback; hot work 950–1150 °C followed by mandatory solution anneal and rapid quench.
What is the maximum service temperature of S32950?
S32950 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S32950 Annealed and S32950-CW?
Annealed is the default condition — standard supply condition for plate, bar, tube and fittings; best corrosion resistance and toughness. CW: springs, clamps and wire products where maximum strength outweighs ductility and toughness. Yield strength is 560 MPa in Annealed versus 830 MPa in CW.
How much does S32950 cost?
S32950 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 — ASTM International (2023)
- ASTM A789/A790 — Duplex Stainless Steel Tubing and Pipe — ASTM International (2021)
- ASTM A182 / A815 — Forged Fittings and Flanges — ASTM International (2022)
- 7-Mo PLUS (UNS S32950) Duplex Stainless Alloy Data — Carpenter Technology (2020)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Practical Guidelines for the Fabrication of Duplex Stainless Steels — IMOA (2014)
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.