Stainless Steel 301 Three-Quarter Hard
Supply condition
AISI/SAE 301 · UNS S30100 · EN 1.4310, X12CrNi17-7 · JIS SUS301 · GB 1Cr17Ni7, 12Cr17Ni7
Choose for flat springs and high-strength panels needing only mild forming.
Values for the Three-Quarter 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 | — |
Three-Quarter HardThis page 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 | — |
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 Three-Quarter Hard?
301 Three-Quarter Hard is 301 supplied in the Three-Quarter Hard condition — choose for flat springs and high-strength panels needing only mild forming. 301 Three-Quarter Hard has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,280 MPa (186 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 193 GPa (28 Msi). 301 Three-Quarter 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; Three-Quarter Hard is available on request or by drawing note.
Advantages
- High strength — 1,000 MPa (145 ksi), better than 98% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
Limitations
- Limited ductility — 15%, worse than 89% of stainless steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 88% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- High embodied carbon — 5.8 kg CO₂/kg, worse than 86% of stainless steel grades
- Limited service temperature — 350°C (662 °F), worse than 84% of stainless steel grades
301 Three-Quarter Hard properties
Typical room-temperature values for 301 Three-Quarter 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 Three-Quarter 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 Three-Quarter Hard has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,280 MPa (186 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 15% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
301 Three-Quarter Hard is rated for continuous service to 350°C (662 °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 Three-Quarter Hard conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (56/100), worse than 66% of stainless steel grades.
Sustainability4
Producing a kilogram of 301 Three-Quarter 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 Three-Quarter Hard's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability fair (45/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 301 Three-Quarter 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 Three-Quarter Hard — frequently asked
What is 301 Three-Quarter Hard used for?
301 Three-Quarter 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 Three-Quarter Hard?
301 Three-Quarter Hard has a typical yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,280 MPa (186 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 9 listed tempers.
Is 301 Three-Quarter Hard easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% 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 Three-Quarter Hard be welded?
With care — weldability is rated fair (45/100). 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 Three-Quarter 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 Three-Quarter 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 Three-Quarter Hard?
301 Three-Quarter Hard is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 301 Three-Quarter Hard?
Yes — 301 Three-Quarter 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.