Stainless Steel S40945 1/4H
Supply condition
UNS S40945
1/4H = quarter hard
Occasional cold-worked strip order when higher yield is needed for clamps, brackets and stiff roll-formed sections.
Values for the 1/4H condition
Other S40945 tempers and conditions
S40945 is listed in 4 conditions; see the grade overview at S40945.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault cold rolled, annealed and pickled (2B / 2D sheet & strip) | Standard stocked condition for exhaust sheet and tube stock — best formability and weldability. | 250 | 450 | 32 | 145 HB | — |
As-welded deposit | Typical condition of ERW/laser-welded exhaust tubing — Ti stabilization keeps the HAZ corrosion-resistant without annealing. | 255 | 440 | 25 | 155 HB | 2.9 % IACS |
Temper rolled / skin passed after anneal | Light cold roll for flatness, stretcher-strain suppression and a modest strength bump in roll-formed parts. | 330 | 480 | 25 | 165 HB | 2.9 % IACS |
1/4HThis page Quarter hard | Occasional cold-worked strip order when higher yield is needed for clamps, brackets and stiff roll-formed sections. | 450 | 550 | 12 | 13 HRC | 2.9 % IACS |
What is S40945 1/4H?
S40945 1/4H is S40945 supplied in the 1/4H condition — occasional cold-worked strip order when higher yield is needed for clamps, brackets and stiff roll-formed sections. S40945 1/4H has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 70% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi). S40945 1/4H has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,450°C (2,642 °F). Annealed is the default condition FabDigit quotes; 1/4H is available on request or by drawing note.
Advantages
- Low embodied carbon — 2.6 kg CO₂/kg, better than 100% of stainless steel grades
- Easy to machine — 63/100, better than 98% of stainless steel grades
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Readily welded — 85/100, better than 87% of stainless steel grades
Limitations
- Needs corrosion protection — 37/100, worse than 96% of stainless steel grades
- Limited ductility — 12%, worse than 95% of stainless steel grades
- Hard to polish — 55/100, worse than 89% of stainless steel grades
S40945 1/4H properties
Typical room-temperature values for S40945 1/4H; 22 are specific to this condition. Other listed values are S40945 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
S40945 1/4H has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,450°C (2,642 °F).
Mechanical15
S40945 1/4H has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 70% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S40945 1/4H is rated for continuous service to 675°C (1,247 °F). It conducts heat at 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades. Thermal expansion is 11.4 µm/m·K (6.33 µin/in·°F).
Electrical3
S40945 1/4H conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (37/100), worse than 96% of stainless steel grades.
Sustainability4
Producing a kilogram of S40945 1/4H takes about 36 MJ of energy and emits 2.6 kg of CO₂ — less than 99% of stainless steel grades. Typical recycled content is 70%.
Manufacturability7
S40945 1/4H's machinability is good (63/100, better than 98% of stainless steel grades); weldability excellent (85/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S40945 1/4H
Is S40945 easy to machine?
Machines much like a low-carbon steel — cuts more freely than 304, but keep tools sharp, use positive rake and rigid setups to avoid the smearing/BUE typical of ferritics.
Can S40945 be welded?
Excellent — GTAW/GMAW/laser/resistance welding without preheat or post-weld anneal; Ti stabilization prevents HAZ sensitization, use 409Ti/430Ti or 309L filler and keep heat input low to limit grain coarsening.
Can S40945 be formed, bent or molded?
Good deep drawing and roll forming (high r, low n); allow generous bend radii (≥1t) and expect less stretch-formability and more springback than austenitic 304; keep forming above ~10 °C to stay clear of the ductile-brittle transition.
What surface finishes work on S40945?
Cannot be anodized — passivate or paint; commonly used bare in exhaust duty where a light surface rust film is acceptable, or aluminized/ceramic-coated for cosmetic and long-life applications.
S40945 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 stabilization efficiency | ≤ 0.03 | 0.02 |
| Mn | ≤ 1 | 0.4 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.02 | 0 |
| Cr | 10.5 – 11.7 | 11.2 |
| Ni | ≤ 0.5 | 0.2 |
| TiTi ≥ 8×(C+N) — the high-Ti stabilization that defines S40945 | 0.15 – 0.5 | 0.25 |
| N | ≤ 0.03 | 0.02 |
| Fe | balance | — |
S40945 1/4H — frequently asked
What is S40945 1/4H used for?
S40945 1/4H is typically used for welded exhaust assemblies, mufflers and tail pipes. In short: highly stabilized 409 variant; best HAZ corrosion resistance; weldable without preheat.
What is the yield strength of S40945 1/4H?
S40945 1/4H has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 70% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is S40945 1/4H easy to machine?
Reasonably — machinability is rated good (63/100, better than 98% of stainless steel grades). Machines much like a low-carbon steel — cuts more freely than 304, but keep tools sharp, use positive rake and rigid setups to avoid the smearing/BUE typical of ferritics.
Can S40945 1/4H be welded?
Yes — weldability is rated excellent (85/100). Excellent — GTAW/GMAW/laser/resistance welding without preheat or post-weld anneal; Ti stabilization prevents HAZ sensitization, use 409Ti/430Ti or 309L filler and keep heat input low to limit grain coarsening.
What surface finishes work on S40945 1/4H?
Cannot be anodized — passivate or paint; commonly used bare in exhaust duty where a light surface rust film is acceptable, or aluminized/ceramic-coated for cosmetic and long-life applications.
Can S40945 1/4H be formed, bent or molded?
Good deep drawing and roll forming (high r, low n); allow generous bend radii (≥1t) and expect less stretch-formability and more springback than austenitic 304; keep forming above ~10 °C to stay clear of the ductile-brittle transition.
What is the maximum service temperature of S40945 1/4H?
S40945 1/4H is rated for continuous use to about 675°C (1,247 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S40945 Annealed and S40945-TR?
Annealed is the default condition — standard stocked condition for exhaust sheet and tube stock — best formability and weldability. TR: light cold roll for flatness, stretcher-strain suppression and a modest strength bump in roll-formed parts. Yield strength is 250 MPa in Annealed versus 330 MPa in TR.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip — ASTM International (2023)
- ASTM A268/A268M — Seamless and Welded Ferritic Stainless Steel Tubing — ASTM International (2022)
- SAE J405 — Chemical Compositions of SAE Wrought Stainless Steels — SAE International (2013)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- Type 409 / 409 Ti ferritic stainless steel product data — AK Steel / Cleveland-Cliffs (2020)
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.