Stainless Steel 317-1/2 Hard
Supply condition
AISI/SAE 317 · UNS S31700 · EN 1.4449 · JIS SUS317 · GB 06Cr19Ni13Mo3
1/2 Hard = half hard
High-strength cold-rolled temper for springy clips, straps and flat springs; limited formability.
Values for the 1/2 Hard condition
Other 317 tempers and conditions
317 is listed in 7 conditions; see the grade overview at 317.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
mill annealed bar / forging condition | Use for hot-finished bar, forgings and fittings where softest, most ductile state is wanted before machining or forming. | 275 | 600 | 50 | 155 HB | 2.3 % IACS |
Finish State | Hot-rolled/hot-forged bar and plate condition per ASTM A276/A479, with a scaled or descaled surface and slightly higher strength and hardness than fully annealed material. | 275 | 585 | 45 | 165 HB | 14 W/m·K |
Solution AnnealedDefault 1040–1120 °C, rapid cool (mill standard) | Standard supply condition for plate, sheet, pipe and tube — maximum corrosion resistance and ductility. | 290 | 620 | 45 | 160 HB | — |
low-temperature (300–400 °C) relief of cold-worked or welded parts | Pick when residual stresses from forming or welding must be lowered without triggering carbide sensitisation. | 330 | 640 | 40 | 170 HB | 2.3 % IACS |
cold-finished bar / wire (as-drawn) | Choose for close-tolerance bright bar and shafting where higher yield strength and better surface than hot-rolled are needed. | 480 | 760 | 28 | 210 HB | — |
Quarter hard | Cold-rolled temper for stiffer light-gauge parts still requiring moderate bending ability. | 515 | 860 | 20 | 25 HRC | 2.3 % IACS |
1/2 HardThis page Half hard | High-strength cold-rolled temper for springy clips, straps and flat springs; limited formability. | 760 | 1,035 | 12 | 32 HRC | 2.3 % IACS |
What is 317-1/2 Hard?
317-1/2 Hard is 317 supplied in the 1/2 Hard condition — high-strength cold-rolled temper for springy clips, straps and flat springs; limited formability. 317-1/2 Hard has a yield strength of 760 MPa (110 ksi) and a tensile strength of 1,035 MPa (150 ksi) — stronger than 94% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi). 317-1/2 Hard has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,375°C (2,507 °F). Solution Annealed is the default condition FabDigit quotes; 1/2 Hard is available on request or by drawing note.
Advantages
- High strength — 760 MPa (110 ksi), better than 94% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
- Good corrosion resistance — 76/100, better than 80% of stainless steel grades
Limitations
- Limited ductility — 12%, worse than 95% of stainless steel grades
317-1/2 Hard properties
Typical room-temperature values for 317-1/2 Hard; 22 are specific to this condition. Other listed values are 317 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
317-1/2 Hard has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,375°C (2,507 °F).
Mechanical15
317-1/2 Hard has a yield strength of 760 MPa (110 ksi) and a tensile strength of 1,035 MPa (150 ksi) — stronger than 94% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
317-1/2 Hard is rated for continuous service to 425°C (797 °F). It conducts heat at 14.4 W/m·K (8.32 BTU/hr·ft·°F), worse than 75% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
317-1/2 Hard conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (76/100), better than 80% of stainless steel grades.
Sustainability4
Producing a kilogram of 317-1/2 Hard takes about 78 MJ of energy and emits 5.2 kg of CO₂ — more than 87% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
317-1/2 Hard's machinability is fair (40/100, better than 72% of stainless steel grades); weldability good (65/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 317-1/2 Hard
Is 317 easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed and flood coolant; avoid dwelling to prevent glazing.
Can 317 be welded?
Weld readily by GTAW/GMAW/SMAW with 317L or ER318 filler, low heat input, no preheat; the 0.08 % C base grade can sensitise, so prefer 317L or post-weld solution anneal for aggressive service.
Can 317 be formed, bent or molded?
Excellent cold formability but high work-hardening rate — allow 40–50 % more press force than carbon steel, generous radii, and interstage anneal for deep draws.
What surface finishes work on 317?
Pickle and passivate (ASTM A967) or electropolish after welding to restore the passive film; polishes to a No.4 or No.8 mirror finish and cannot be anodised.
317 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 |
|---|---|---|
| C0.08 max; 317L is ≤0.030 for welded service | ≤ 0.08 | 0.05 |
| Si | ≤ 0.75 | 0.5 |
| Mn | ≤ 2 | 1.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0.02 |
| Cr | 18 – 20 | 19 |
| Ni | 11 – 15 | 13 |
| Mo | 3 – 4 | 3.5 |
| NASTM A240 limit | ≤ 0.1 | 0.05 |
| Fe | balance | — |
317-1/2 Hard — frequently asked
What is 317-1/2 Hard used for?
317-1/2 Hard is typically used for pulp and paper bleaching equipment, FGD scrubber internals and ducting, chemical process vessels and piping, acid handling tanks and pumps, heat exchanger shells and tubes and flue gas condensers. In short: higher-molybdenum austenitic stainless.
What is the yield strength of 317-1/2 Hard?
317-1/2 Hard has a typical yield strength of 760 MPa (110 ksi) and a tensile strength of 1,035 MPa (150 ksi) — stronger than 94% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 317-1/2 Hard easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy constant feed, low-to-moderate speed and flood coolant; avoid dwelling to prevent glazing.
Can 317-1/2 Hard be welded?
Yes — weldability is rated good (65/100). Weld readily by GTAW/GMAW/SMAW with 317L or ER318 filler, low heat input, no preheat; the 0.08 % C base grade can sensitise, so prefer 317L or post-weld solution anneal for aggressive service.
What surface finishes work on 317-1/2 Hard?
Pickle and passivate (ASTM A967) or electropolish after welding to restore the passive film; polishes to a No.4 or No.8 mirror finish and cannot be anodised.
Can 317-1/2 Hard be formed, bent or molded?
Excellent cold formability but high work-hardening rate — allow 40–50 % more press force than carbon steel, generous radii, and interstage anneal for deep draws.
What is the maximum service temperature of 317-1/2 Hard?
317-1/2 Hard is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 317-1/2 Hard?
Yes — 317-1/2 Hard is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A240/A240M — Cr and Cr-Ni Stainless Steel Plate, Sheet and Strip — ASTM International (2023)
- ASTM A276/A479 — Stainless Steel Bars and Shapes — ASTM International (2022)
- EN 10088-2 (X5CrNiMo17-13-3, 1.4449) — CEN (2014)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Outokumpu Steel Grades / Corrosion Tables (317, 317L) — Outokumpu (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.