Stainless Steel S32900
UNS S32900 · AISI/SAE 329
S32900 (UNS S32900, type 329) is one of the original commercial ferritic-austenitic duplex stainless steels, predating the modern nitrogen-alloyed grades.
Reference datasheet — S32900 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
S32900 tempers and conditions
S32900 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 |
|---|---|---|---|---|---|---|
Hot Finished, Annealed Bar (ASTM A276/A479) | Use for large-diameter bar, flanges and valve-body forgings; hot finishing plus anneal matches annealed plate at 520 MPa yield, with slightly lower toughness in heavy sections. | 520 | 700 | 25 | 22 HRC | 2.2 % IACS |
AnnealedDefault solution annealed and quenched plate/sheet (ASTM A240) | Standard stock condition: solution annealing near 1000 °C followed by water quench balances the two phases for best corrosion resistance and toughness at 540 MPa yield. | 540 | 720 | 27 | 23 HRC | 2.2 % IACS |
Cold Rolled, Annealed and Pickled Sheet (2B/2D) | Choose thin-gauge sheet in 2B/2D pickled finish for linings and thin-wall heat exchanger parts; cold rolled then annealed for 550 MPa yield and 25% elongation. | 550 | 730 | 25 | 24 HRC | 2.2 % IACS |
annealed then cold drawn to size | Pick for small-diameter precision bar needing tight size and good surface; drawing after annealing raises yield to 690 MPa but cuts elongation to 18% and limits forming. | 690 | 830 | 18 | 28 HRC | 2.2 % IACS |
Supply forms, finishes and certifications
Ways S32900 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Annealed Tube | Solution annealed seamless/welded tubing | Supply form |
What is S32900?
S32900 (UNS S32900, type 329) is one of the original commercial ferritic-austenitic duplex stainless steels, predating the modern nitrogen-alloyed grades. Engineers specify it for chloride stress-corrosion cracking resistance and roughly double the yield strength of 304 — 540 MPa yield, 720 MPa tensile, 27 % elongation at 240 HB (23 HRC) — in annealed tube, hot-finished bar, cold-drawn bar and cold-rolled annealed sheet. Service is limited to about 300 °C because of 475 °C embrittlement, and the absence of nitrogen means weld heat-affected zones lose phase balance unless a post-weld solution anneal is possible. S31803/S32205 (2205) is the usual modern substitute. S32900 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,400°C (2,552 °F). S32900 has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 82% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
What is S32900 used for?
- heat exchanger tubing
- condensers
- acid processing equipment
Advantages
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
- High strength — 540 MPa (78.3 ksi), better than 82% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 77% of stainless steel grades
S32900 properties
Typical room-temperature values for S32900-Annealed; bars are the position among stainless steel grades.
Physical3
S32900 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical17
S32900 has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 82% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S32900 is rated for continuous service to 300°C (572 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), better than 58% of stainless steel grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
S32900 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 S32900 takes about 55 MJ of energy and emits 5.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
S32900's machinability is fair (35/100, better than 51% of stainless steel grades); weldability good (55/100); 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. S32900 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S32900
Is S32900 easy to machine?
Work-hardens strongly and needs roughly 1.5 times the cutting force of 304. Use a rigid machine, low speed with heavy feed, sharp coated carbide tooling and flood coolant, and never allow the tool to dwell or rub.
Can S32900 be welded?
GTAW, GMAW and SMAW are all usable with over-alloyed 2209 / E2209-type filler and heat input controlled to 0.5–2.0 kJ/mm. Because the base metal carries no nitrogen, a post-weld solution treatment at 1010–1120 °C followed by water quench should be applied wherever possible to restore ferrite/austenite balance and toughness.
Can S32900 be formed, bent or molded?
Cold forming requires much higher force than austenitic stainless and generous springback compensation. Hot form at 950–1150 °C and follow with a full solution anneal and water quench; do not dwell or finish forming in the 650–950 °C range where sigma phase precipitates.
S32900 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 |
|---|---|---|
| CASTM A240 | ≤ 0.08 | 0.05 |
| Mn | ≤ 1 | 0.6 |
| Si | ≤ 0.75 | 0.5 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Cr | 23 – 28 | 26 |
| Ni | 2.5 – 5 | 4 |
| Mo | 1 – 2 | 1.5 |
| Nno N specified in base grade; A789/A790 use 0.10 max or none | ≈ 0.05 | 0.05 |
| Fe | balance |
What surface finishes work on S32900?
Pickle and passivate (nitric/hydrofluoric) to restore the passive film after welding or hot work. The surface can be mechanically polished to a mirror finish; anodizing does not apply, and all weld heat tint must be removed to keep corrosion resistance.
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 S32900 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- AISI / SAE
- 329
How much does S32900 cost?
S32900 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.
S32900 — frequently asked
What is S32900 used for?
S32900 is typically used for heat exchanger tubing, condensers and acid processing equipment. In short: first-generation duplex stainless; chloride SCC resistant; largely superseded by 2205.
What is the yield strength of S32900?
S32900 has a typical yield strength of 540 MPa (78.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 82% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is S32900 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Work-hardens strongly and needs roughly 1.5 times the cutting force of 304. Use a rigid machine, low speed with heavy feed, sharp coated carbide tooling and flood coolant, and never allow the tool to dwell or rub.
Can S32900 be welded?
Yes — weldability is rated good (55/100). GTAW, GMAW and SMAW are all usable with over-alloyed 2209 / E2209-type filler and heat input controlled to 0.5–2.0 kJ/mm. Because the base metal carries no nitrogen, a post-weld solution treatment at 1010–1120 °C followed by water quench should be applied wherever possible to restore ferrite/austenite balance and toughness.
What surface finishes work on S32900?
Pickle and passivate (nitric/hydrofluoric) to restore the passive film after welding or hot work. The surface can be mechanically polished to a mirror finish; anodizing does not apply, and all weld heat tint must be removed to keep corrosion resistance.
Can S32900 be formed, bent or molded?
Cold forming requires much higher force than austenitic stainless and generous springback compensation. Hot form at 950–1150 °C and follow with a full solution anneal and water quench; do not dwell or finish forming in the 650–950 °C range where sigma phase precipitates.
What is the maximum service temperature of S32900?
S32900 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.
How much does S32900 cost?
S32900 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 — Ferritic/Austenitic Stainless Steel Tubing and Pipe — ASTM International (2021)
- ASTM A276/A479 — Stainless Steel Bars and Shapes — ASTM International (2022)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Duplex stainless steel data sheets (Type 329 / S32900) — Outokumpu / Sandvik (2020)
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.