Stainless Steel 309S-1/4 Hard
Supply condition
AISI/SAE 309S · UNS S30908 · EN 1.4833, X12CrNi23-13 · JIS SUS309S · GB 06Cr23Ni13
1/4 Hard = quarter hard
Lightly cold-rolled strip where extra spring/stiffness is wanted and forming demands are modest.
Values for the 1/4 Hard condition
Other 309S tempers and conditions
309S is listed in 6 conditions; see the grade overview at 309S.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
mill annealed / softened condition (bar, forging, tube) | General softened supply condition for bar, forgings and tube where full solution treatment is not separately certified. | 270 | 540 | 45 | 160 HB | 2.2 % IACS |
Hot Rolled, Annealed and Pickled plate (1D) | Most common heavy-plate form (3 mm and up) for furnace hearths, retorts and baffles. | 275 | 560 | 45 | 160 HB | 2.2 % IACS |
Solution AnnealedDefault 1050–1120 °C, rapid cool (ASTM A240 / EN 1.4833 plate & sheet) | Standard stocked condition for plate and sheet destined for high-temperature furnace and welded fabrication work. | 280 | 550 | 45 | 165 HB | — |
Cold Rolled, Annealed, Pickled and skin-passed sheet | Thin sheet (<3 mm) with a smoother 2B surface for fabricated liners, ducting and shielding. | 300 | 590 | 45 | 170 HB | 2.2 % IACS |
Cold Drawn bar / wire (as-drawn, not re-annealed) | Choose for small-diameter bar and fasteners needing higher strength and better surface/straightness than hot-finished bar. | 480 | 700 | 25 | 220 HB | — |
1/4 HardThis page Quarter hard | Lightly cold-rolled strip where extra spring/stiffness is wanted and forming demands are modest. | 520 | 760 | 20 | 22 HRC | 2.2 % IACS |
What is 309S-1/4 Hard?
309S-1/4 Hard is 309S supplied in the 1/4 Hard condition — lightly cold-rolled strip where extra spring/stiffness is wanted and forming demands are modest. 309S-1/4 Hard has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 79% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi). 309S-1/4 Hard has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F). Solution Annealed is the default condition FabDigit quotes; 1/4 Hard is available on request or by drawing note.
Advantages
- High service temperature — 850°C (1,562 °F), better than 80% of stainless steel grades
- High strength — 520 MPa (75.4 ksi), better than 79% of stainless steel grades
Limitations
- Limited ductility — 20%, worse than 79% of stainless steel grades
309S-1/4 Hard properties
Typical room-temperature values for 309S-1/4 Hard; 24 are specific to this condition. Other listed values are 309S reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
309S-1/4 Hard has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
309S-1/4 Hard has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 79% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
309S-1/4 Hard is rated for continuous service to 850°C (1,562 °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-1/4 Hard conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (64/100), better than 54% of stainless steel grades.
Sustainability4
Producing a kilogram of 309S-1/4 Hard 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-1/4 Hard's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability very good (75/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 309S-1/4 Hard
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-1/4 Hard — frequently asked
What is 309S-1/4 Hard used for?
309S-1/4 Hard 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-1/4 Hard?
309S-1/4 Hard has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 79% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 309S-1/4 Hard easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% 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-1/4 Hard be welded?
Yes — weldability is rated very good (75/100). 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-1/4 Hard?
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-1/4 Hard 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-1/4 Hard?
309S-1/4 Hard is rated for continuous use to about 850°C (1,562 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 309S-1/4 Hard?
Yes — 309S-1/4 Hard is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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.