Stainless Steel S40910-ANN (Annealed)
Heat-treated state · default condition
UNS S40910
Default stocked condition for exhaust stamping, roll-forming and welded tube making.
Values for the ANN condition
Other S40910 tempers and conditions
S40910 is listed in 3 conditions; see the grade overview at S40910.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As-welded deposit | Reference condition for joint design: stabilized chemistry keeps weld-zone corrosion close to base metal, but weld ductility and toughness drop. | 250 | 420 | 18 | 165 HB | 2.9 % IACS |
ANNDefaultThis page Annealed | Default stocked condition for exhaust stamping, roll-forming and welded tube making. | 270 | 440 | 31 | 150 HB | 2.9 % IACS |
Temper rolled | Pick when extra stiffness/spring-back is needed in roll-formed or clamped parts and deep drawing is not required. | 420 | 520 | 12 | 10 HRC | 2.9 % IACS |
What is S40910-ANN?
S40910-ANN is S40910 heat treated to ANN — default stocked condition for exhaust stamping, roll-forming and welded tube making. S40910-ANN has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 79% of stainless steel grades. Elongation at break is 31% and the elastic modulus is 200 GPa (29 Msi). S40910-ANN has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,480°C (2,696 °F).
Advantages
- Easy to machine — 55/100, better than 94% of stainless steel grades
- Conducts heat well — 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% 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
- Forms and bends easily — 75/100, better than 87% of stainless steel grades
Limitations
- Hard to polish — 50/100, worse than 93% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
- Low strength — 270 MPa (39.2 ksi), worse than 79% of stainless steel grades
S40910-ANN properties
Typical room-temperature values for S40910-ANN; 21 are specific to this condition. Other listed values are S40910 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
S40910-ANN has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,480°C (2,696 °F).
Mechanical15
S40910-ANN has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 79% of stainless steel grades. Elongation at break is 31% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S40910-ANN is rated for continuous service to 675°C (1,247 °F). It conducts heat at 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
S40910-ANN conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of S40910-ANN takes about 48 MJ of energy and emits 3.6 kg of CO₂ — less than 85% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
S40910-ANN's machinability is good (55/100, better than 94% of stainless steel grades); weldability excellent (85/100); formability very good (75/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S40910-ANN
Is S40910 easy to machine?
Machines like a soft low-alloy steel but is gummy: use sharp positive-rake carbide, heavy feeds, rigid setups and flood coolant to avoid built-up edge; ~65 % of AISI 1212.
Can S40910 be welded?
Excellent for GTAW/GMAW/laser/resistance welding thanks to Ti(+Nb) stabilization — no PWHT needed; limit heat input and use Ar or Ar+He (no nitrogen) to curb grain coarsening, and match with 409Nb/439 filler or 308L/309L for dissimilar joints.
Can S40910 be formed, bent or molded?
Good deep-drawing and roll-forming behaviour in the annealed condition (r-value favours stretch-draw exhaust shells); watch ridging/roping on drawn surfaces and allow slightly larger bend radii than 304.
What surface finishes work on S40910?
Not anodizable; use pickling/passivation, aluminized or Al-Si coating, or high-temperature silicone paint for cosmetic/wet-corrosion service; mechanical polishing gives only a modest luster because of coarse ferritic grain.
S40910 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 ferritic | ≤ 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 |
| N | ≤ 0.03 | 0.02 |
| TiTi min = 0.05 + 2(C+N); stabilizer | 0.05 – 0.5 | 0.2 |
| Nboptional co-stabilizer in some mill practices | ≤ 0.1 | 0.03 |
| Fe | balance | — |
S40910-ANN — frequently asked
What is S40910-ANN used for?
S40910-ANN is typically used for exhaust pipes, mufflers and catalytic converter shells. In short: weld-stabilized exhaust ferritic; low-cost 11% Cr stainless; good draw formability.
What is the yield strength of S40910-ANN?
S40910-ANN has a typical yield strength of 270 MPa (39.2 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 79% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is S40910-ANN easy to machine?
Reasonably — machinability is rated good (55/100, better than 94% of stainless steel grades). Machines like a soft low-alloy steel but is gummy: use sharp positive-rake carbide, heavy feeds, rigid setups and flood coolant to avoid built-up edge; ~65 % of AISI 1212.
Can S40910-ANN be welded?
Yes — weldability is rated excellent (85/100). Excellent for GTAW/GMAW/laser/resistance welding thanks to Ti(+Nb) stabilization — no PWHT needed; limit heat input and use Ar or Ar+He (no nitrogen) to curb grain coarsening, and match with 409Nb/439 filler or 308L/309L for dissimilar joints.
What surface finishes work on S40910-ANN?
Not anodizable; use pickling/passivation, aluminized or Al-Si coating, or high-temperature silicone paint for cosmetic/wet-corrosion service; mechanical polishing gives only a modest luster because of coarse ferritic grain.
Can S40910-ANN be formed, bent or molded?
Good deep-drawing and roll-forming behaviour in the annealed condition (r-value favours stretch-draw exhaust shells); watch ridging/roping on drawn surfaces and allow slightly larger bend radii than 304.
What is the maximum service temperature of S40910-ANN?
S40910-ANN 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 S40910-ANN and S40910-TR?
ANN is the default condition — default stocked condition for exhaust stamping, roll-forming and welded tube making. TR: pick when extra stiffness/spring-back is needed in roll-formed or clamped parts and deep drawing is not required. Yield strength is 270 MPa in ANN versus 420 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/Martensitic Stainless Steel Tubing — ASTM International (2022)
- ASTM A959 — Harmonized Standard Grade Compositions for Wrought Stainless Steels — ASTM International (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Type 409/409L Ferritic Stainless Steel product data — Cleveland-Cliffs (AK Steel) / Outokumpu (2021)
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.