Stainless Steel S20431-FH (Full hard)
Supply condition
UNS S20431
Maximum strength/spring-back strip for flat springs, shims, blades and banding; not for bending.
Values for the FH condition
Other S20431 tempers and conditions
S20431 is listed in 7 conditions; see the grade overview at S20431.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault Annealed (cold-rolled sheet/strip, 2B / 2D / BA finish) | Default stock condition for forming, drawing, roll-forming and decorative sheet. | 380 | 760 | 52 | 85 HRB | — |
1/16 Hard | Slight stiffening with almost annealed formability; common for skin-passed decorative strip. | 420 | 790 | 45 | 10 HRC | 2.5 % IACS |
1/8 Hard | Use where mild bending is still needed but flatness/stiffness must improve over annealed. | 480 | 830 | 40 | 14 HRC | 2.5 % IACS |
Quarter hard | Most common structural temper: good stiffness with usable 90° bending across the rolling direction. | 620 | 930 | 27 | 25 HRC | 2.5 % IACS |
Half hard | For load-bearing panels, clamps and rail sections where high yield beats formability. | 860 | 1,110 | 18 | 32 HRC | 2.4 % IACS |
Three-quarter hard | High-strength strip for straps, springy clips and lightweight profiles; only large-radius bending. | 1,010 | 1,270 | 13 | 37 HRC | 2.4 % IACS |
FHThis page Full hard | Maximum strength/spring-back strip for flat springs, shims, blades and banding; not for bending. | 1,130 | 1,380 | 9 | 41 HRC | 2.4 % IACS |
What is S20431-FH?
S20431-FH is S20431 supplied in the FH condition — maximum strength/spring-back strip for flat springs, shims, blades and banding; not for bending. S20431-FH has a yield strength of 1,130 MPa (164 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 9% and the elastic modulus is 197 GPa (28.6 Msi). S20431-FH 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). Annealed is the default condition FabDigit quotes; FH is available on request or by drawing note.
Advantages
- High strength — 1,130 MPa (164 ksi), better than 98% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
- Low embodied carbon — 3.8 kg CO₂/kg, better than 77% of stainless steel grades
Limitations
- Limited ductility — 9%, worse than 99% of stainless steel grades
- Limited service temperature — 290°C (554 °F), worse than 94% of stainless steel grades
- Limited formability — 18/100, worse than 89% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
- Low fracture toughness — 80 MPa·√m (72.8 ksi·√in), worse than 79% of stainless steel grades
S20431-FH properties
Typical room-temperature values for S20431-FH; 23 are specific to this condition. Other listed values are S20431 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
S20431-FH 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).
Mechanical15
S20431-FH has a yield strength of 1,130 MPa (164 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 9% and the elastic modulus is 197 GPa (28.6 Msi).
Thermal6
S20431-FH is rated for continuous service to 290°C (554 °F). It conducts heat at 16.2 W/m·K (9.36 BTU/hr·ft·°F), better than 64% of stainless steel grades. Thermal expansion is 15.7 µm/m·K (8.72 µin/in·°F).
Electrical3
S20431-FH conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of S20431-FH takes about 45 MJ of energy and emits 3.8 kg of CO₂ — less than 91% of stainless steel grades. Typical recycled content is 55%.
Manufacturability6
S20431-FH's machinability is poor (34/100, worse than 55% of stainless steel grades); weldability fair (45/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S20431-FH
Is S20431 easy to machine?
Treat like a tougher 304: rigid setups, positive-rake sharp carbide, heavy constant feed and generous coolant to avoid work-hardened glazing and built-up edge.
Can S20431 be welded?
GTAW/GMAW/resistance welding all work with 308L or 209 (Cr-Mn-N) filler; keep heat input low, no preheat, and avoid long dwell in 450–850 °C given the 0.15 % C allowance.
Can S20431 be formed, bent or molded?
Excellent stretch and deep-draw response thanks to Cu+N, but expect 30–50 % higher press loads and springback than 304 — overbend, use larger die radii and polished tooling to limit galling.
What surface finishes work on S20431?
Takes No.4 brushed, hairline, BA and mirror polish well and is widely PVD-coated; passivate after fabrication and avoid chloride-heavy cleaners, since its pitting margin is well below 304.
S20431 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 |
|---|---|---|
| Cmax only | ≤ 0.15 | 0.08 |
| MnNi-substituting austenite stabiliser | 6 – 9 | 7.5 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Cr | 15 – 17.5 | 16.3 |
| Nilow-nickel design | 0.5 – 2.5 | 1.5 |
| Cuimproves deep-drawing and softens work hardening | 1 – 3 | 2 |
| Ninterstitial strengthener / austenite stabiliser | 0.05 – 0.25 | 0.15 |
| Febalance; ranges follow ASTM A240/A666 2xx Cr-Mn-Ni-Cu-N listing — verify against mill certificate | balance | — |
S20431-FH — frequently asked
What is S20431-FH used for?
S20431-FH is typically used for architectural panels, structural tubing and sinks and appliances. In short: most formable 201-type; low-nickel 304 substitute; corrosion below 304.
What is the yield strength of S20431-FH?
S20431-FH has a typical yield strength of 1,130 MPa (164 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is S20431-FH easy to machine?
Not especially — machinability is rated poor (34/100, worse than 55% of stainless steel grades). Treat like a tougher 304: rigid setups, positive-rake sharp carbide, heavy constant feed and generous coolant to avoid work-hardened glazing and built-up edge.
Can S20431-FH be welded?
With care — weldability is rated fair (45/100). GTAW/GMAW/resistance welding all work with 308L or 209 (Cr-Mn-N) filler; keep heat input low, no preheat, and avoid long dwell in 450–850 °C given the 0.15 % C allowance.
What surface finishes work on S20431-FH?
Takes No.4 brushed, hairline, BA and mirror polish well and is widely PVD-coated; passivate after fabrication and avoid chloride-heavy cleaners, since its pitting margin is well below 304.
Can S20431-FH be formed, bent or molded?
Excellent stretch and deep-draw response thanks to Cu+N, but expect 30–50 % higher press loads and springback than 304 — overbend, use larger die radii and polished tooling to limit galling.
What is the maximum service temperature of S20431-FH?
S20431-FH is rated for continuous use to about 290°C (554 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S20431 Annealed and S20431-FH?
Annealed is the default condition — default stock condition for forming, drawing, roll-forming and decorative sheet. FH: maximum strength/spring-back strip for flat springs, shims, blades and banding; not for bending. Yield strength is 380 MPa in Annealed versus 1,130 MPa in FH.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A666 — Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar — ASTM International (2015)
- GB/T 3280 (12Cr17Mn6Ni5N / 201 ) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Type 201 / 201LN / 204Cu low-nickel austenitic stainless data sheets — stainless flat-product producers (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.