Stainless Steel 309S · heat-treated state · default condition
Stainless Steel 309S Solution Annealed
Properties of the Solution Annealed condition, compared with the other 309S tempers.
Standard stocked condition for plate and sheet destined for high-temperature furnace and welded fabrication work.
What is 309S Solution Annealed?
309S Solution Annealed is 309S heat treated to Solution Annealed — standard stocked condition for plate and sheet destined for high-temperature furnace and welded fabrication work. 309S Solution Annealed has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi). 309S Solution Annealed has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 67% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Advantages
- High service temperature — 1,000°C (1,832 °F), better than 88% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 84% of stainless steel grades
- Readily welded — 80/100, better than 79% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Low strength — 280 MPa (40.6 ksi), worse than 75% of stainless steel grades
309S Solution Annealed properties
Typical room-temperature values for 309S Solution Annealed — 16 properties are specific to this condition; the rest are grade-level values shared by every 309S temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
309S Solution Annealed has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 67% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
309S Solution Annealed has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
309S Solution Annealed is rated for continuous service to 1,000°C (1,832 °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 15 µm/m·K (8.33 µin/in·°F).
Electrical3
309S Solution Annealed conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of 309S Solution Annealed takes about 62 MJ of energy and emits 4.6 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
309S Solution Annealed's machinability is fair (38/100, better than 63% of stainless steel grades); weldability very good (80/100); formability good (62/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 309S tempers and conditions
309S is also supplied in 5 other conditions. The full side-by-side table is on the 309S overview.
- Solution AnnealedDefaultStandard stocked condition for plate and sheet destined for high-temperature furnace and welded fabrication work.280 MPa yield · 165 HB
- 1/4 HardLightly cold-rolled strip where extra spring/stiffness is wanted and forming demands are modest.520 MPa yield · 240 HB
- Cold DrawnChoose for small-diameter bar and fasteners needing higher strength and better surface/straightness than hot-finished bar.480 MPa yield · 220 HB
- Cold Rolled Annealed 2BThin sheet (<3 mm) with a smoother 2B surface for fabricated liners, ducting and shielding.300 MPa yield · 170 HB
- Hot Rolled AnnealedMost common heavy-plate form (3 mm and up) for furnace hearths, retorts and baffles.275 MPa yield · 160 HB
- AnnealedGeneral softened supply condition for bar, forgings and tube where full solution treatment is not separately certified.270 MPa yield · 160 HB
Working with 309S Solution Annealed
Is 309S easy to machine?
Work-hardens rapidly — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed and flood coolant; avoid dwell and re-cutting.
Can 309S be welded?
Readily welded by GTAW/GMAW/SMAW with 309/309L (or 310 for hottest service) filler; no preheat, keep interpass low and avoid long holds at 600–900 °C to limit sigma phase.
Can 309S be formed, bent or molded?
Cold forms like 304 but with higher force and springback; hot work at 1150–1200 °C and re-anneal at 1050–1120 °C with rapid cooling.
What surface finishes work on 309S?
Pickle and passivate after hot work or welding to restore the oxide film; can be ground, polished or electropolished — anodizing does not apply.
309S 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 |
|---|---|---|
| CS30908; EN 1.4833 allows up to 0.15 % | ≤ 0.08 | 0.05 |
| SiEN 1.4833 up to 1.00 % | ≤ 0.75 | 0.5 |
| Mn | ≤ 2 | 1.3 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Cr | 22 – 24 | 23 |
| Ni | 12 – 15 | 13.5 |
| N | ≤ 0.1 | 0.05 |
| Fe | balance | — |
309S Solution Annealed — frequently asked
What is 309S Solution Annealed used for?
309S Solution Annealed is typically used for welded furnace fittings, boiler baffles, heat-treatment fixtures and baskets, furnace muffles and liners, radiant tubes and burner parts and kiln and oven conveyor components. In short: high-temp austenitic stainless.
What is the yield strength of 309S Solution Annealed?
309S Solution Annealed has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 75% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 309S Solution Annealed easy to machine?
Not especially — machinability is rated fair (38/100, better than 63% of stainless steel grades). Work-hardens rapidly — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed and flood coolant; avoid dwell and re-cutting.
Can 309S Solution Annealed be welded?
Yes — weldability is rated very good (80/100). Readily welded by GTAW/GMAW/SMAW with 309/309L (or 310 for hottest service) filler; no preheat, keep interpass low and avoid long holds at 600–900 °C to limit sigma phase.
What surface finishes work on 309S Solution Annealed?
Pickle and passivate after hot work or welding to restore the oxide film; can be ground, polished or electropolished — anodizing does not apply.
Can 309S Solution Annealed be formed, bent or molded?
Cold forms like 304 but with higher force and springback; hot work at 1150–1200 °C and re-anneal at 1050–1120 °C with rapid cooling.
What is the maximum service temperature of 309S Solution Annealed?
309S Solution Annealed is rated for continuous use to about 1,000°C (1,832 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 309S Solution Annealed?
Yes — 309S Solution Annealed is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip (UNS S30908) — ASTM International (2023)
- EN 10095 / EN 10088-1 — Heat resisting steels and nickel alloys (X12CrNi23-13, 1.4833) — CEN (2018)
- JIS G 4304/G 4305 — Hot/Cold rolled stainless steel plate, sheet and strip (SUS309S) — JISC (2021)
- GB/T 4237 / GB/T 24511 — (06Cr23Ni13) — SAC (2015)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- Heat resistant stainless steel 4833/309S datasheet — Outokumpu (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.