Stainless Steel 301 Extra Hard
Supply condition
AISI/SAE 301 · UNS S30100 · EN 1.4310, X12CrNi17-7 · JIS SUS301 · GB 1Cr17Ni7, 12Cr17Ni7
Thin-gauge strip for flat springs and constant-force parts where the highest strength is required.
Values for the Extra Hard condition
Other 301 tempers and conditions
301 is listed in 9 conditions; see the grade overview at 301.
- Annealed
- sixteenth_hard
- eighth_hard
- Cold Rolled
- Quarter Hard
- Half Hard
- Three-Quarter Hard
- Full Hard
- Extra Hard
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
solution annealed / soft temper (2B, 2D, BA) | Pick for deep drawing, severe forming or welding; softest and least magnetic condition. | 280 | 760 | 55 | 165 HB | — |
1/16 Hard | Very lightly temper-rolled 301 strip/sheet (ASTM A666 1/16-Hard) — small strength gain over annealed while keeping near-annealed formability. | 400 | 800 | 45 | 200 HB | 2.4 % IACS |
1/8 Hard | Lightly cold-rolled 301 strip/sheet to ASTM A666 1/8-Hard temper — modest strength increase with still-generous bending and forming ductility. | 500 | 860 | 40 | 225 HB | 2.4 % IACS |
Cold RolledDefault light cold-rolled temper (≈1/8–1/4 hard strip/sheet) | Most commonly stocked strip/sheet condition: good strength with usable bendability. | 570 | 900 | 25 | 27 HRC | — |
cold rolled to ASTM A666 quarter-hard temper | Use where moderate bending is still needed but 304-level strength is not enough. | 620 | 950 | 28 | 28 HRC | 2.4 % IACS |
cold rolled to ASTM A666 half-hard temper | Common structural/clip temper: high strength with limited 90° bend capability. | 830 | 1,100 | 20 | 35 HRC | — |
cold rolled to ASTM A666 three-quarter-hard temper | Choose for flat springs and high-strength panels needing only mild forming. | 1,000 | 1,280 | 15 | 39 HRC | 2.4 % IACS |
cold rolled to ASTM A666 full-hard temper | Maximum standard strength for spring clips, shims and wear strip; bend only along grain with generous radii. | 1,100 | 1,350 | 12 | 42 HRC | — |
Extra HardThis page heavily cold-rolled 301 strip (301 EH) | Thin-gauge strip for flat springs and constant-force parts where the highest strength is required. | 1,350 | 1,550 | 6 | 46 HRC | 2.3 % IACS |
What is 301 Extra Hard?
301 Extra Hard is 301 supplied in the Extra Hard condition — thin-gauge strip for flat springs and constant-force parts where the highest strength is required. 301 Extra Hard has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 200 GPa (29 Msi). 301 Extra Hard has a density of 7.88 g/cm³ (0.285 lb/in³), heavier than 59% of stainless steel grades. It melts at 1,395°C (2,543 °F). Cold Rolled is the default condition FabDigit quotes; Extra Hard is available on request or by drawing note.
Advantages
- High strength — 1,350 MPa (196 ksi), better than 99% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
Limitations
- Limited ductility — 6%, worse than 99% of stainless steel grades
- Difficult to machine — 20/100, worse than 98% of stainless steel grades
- Limited formability — 12/100, worse than 93% of stainless steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 92% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
301 Extra Hard properties
Typical room-temperature values for 301 Extra Hard; 23 are specific to this condition. Other listed values are 301 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
301 Extra Hard has a density of 7.88 g/cm³ (0.285 lb/in³), heavier than 59% of stainless steel grades. It melts at 1,395°C (2,543 °F).
Mechanical17
301 Extra Hard has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
301 Extra Hard is rated for continuous service to 300°C (572 °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 16.9 µm/m·K (9.39 µin/in·°F).
Electrical3
301 Extra Hard conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.
Sustainability4
Producing a kilogram of 301 Extra Hard takes about 53 MJ of energy and emits 5.8 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
301 Extra Hard's machinability is poor (20/100, worse than 98% of stainless steel grades); weldability fair (40/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 301 Extra Hard
Is 301 easy to machine?
Gummy and strongly work-hardening: use rigid setups, positive-rake sharp carbide, heavy feed, low-to-moderate speed and flood coolant; never let the tool dwell or the surface will harden.
Can 301 be welded?
Readily GTAW/GMAW/resistance welded with 308L/309L filler; keep heat input low, no preheat, avoid slow cooling in 425–870 °C to limit carbide precipitation, and expect loss of cold-worked strength in the HAZ.
Can 301 be formed, bent or molded?
Excellent stretch formability in the annealed temper thanks to the very high work-hardening rate (n ≈ 0.4), but forces and springback are high and interstage annealing is often needed; bend hard tempers transverse to the rolling direction only.
What surface finishes work on 301?
Not anodizable — passivate per ASTM A967 after machining/welding; takes bright-anneal, No.4 brush and No.8 mirror polish well and accepts PVD colour or electropolishing.
301 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 |
|---|---|---|
| C≤0.15 % (higher than 304 — drives work hardening) | ≤ 0.15 | 0.1 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.05 | |
| SEN 1.4310 allows ≤0.015 | ≤ 0.03 | |
| Cr | 16 – 18 | 17 |
| Nilow Ni keeps austenite metastable | 6 – 8 | 7 |
| N | ≤ 0.1 | |
| Fe | balance |
301 Extra Hard — frequently asked
What is 301 Extra Hard used for?
301 Extra Hard is typically used for flat springs and spring clips, subway and rail car body panels, hose and band clamps, structural formed panels, retaining clips and brackets and spring-temper wire forms. In short: highest strength stainless spring.
What is the yield strength of 301 Extra Hard?
301 Extra Hard has a typical yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,550 MPa (225 ksi) — stronger than 99% of stainless steel grades. Strength varies by condition: see the 9 listed tempers.
Is 301 Extra Hard easy to machine?
Not especially — machinability is rated poor (20/100, worse than 98% of stainless steel grades). Gummy and strongly work-hardening: use rigid setups, positive-rake sharp carbide, heavy feed, low-to-moderate speed and flood coolant; never let the tool dwell or the surface will harden.
Can 301 Extra Hard be welded?
With care — weldability is rated fair (40/100). Readily GTAW/GMAW/resistance welded with 308L/309L filler; keep heat input low, no preheat, avoid slow cooling in 425–870 °C to limit carbide precipitation, and expect loss of cold-worked strength in the HAZ.
What surface finishes work on 301 Extra Hard?
Not anodizable — passivate per ASTM A967 after machining/welding; takes bright-anneal, No.4 brush and No.8 mirror polish well and accepts PVD colour or electropolishing.
Can 301 Extra Hard be formed, bent or molded?
Excellent stretch formability in the annealed temper thanks to the very high work-hardening rate (n ≈ 0.4), but forces and springback are high and interstage annealing is often needed; bend hard tempers transverse to the rolling direction only.
What is the maximum service temperature of 301 Extra Hard?
301 Extra Hard is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 301 Extra Hard?
Yes — 301 Extra Hard is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A666 — Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar — ASTM International (2015)
- EN 10088-2 / EN 10151 — Stainless steels: flat products and spring strip (1.4310) — CEN (2014)
- EN 10270-3 — Steel wire for mechanical springs, stainless spring steel wire — CEN (2011)
- GB/T 3280 / GB/T 20878 (1Cr17Ni7, 12Cr17Ni7) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Outokumpu / Sandvik stainless strip and spring wire datasheets (301, 1.4310) — Outokumpu, Sandvik (2023)
- SMM / Mysteel — SMM / Mysteel (2026)
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.