Stainless Steel 317LM-1/2 Hard
Supply condition
AISI/SAE 317LM · UNS S31725
1/2 Hard = half hard
Highest commonly stocked cold-worked strength level for springs, clamps and strapping; forming is limited to gentle bends.
Values for the 1/2 Hard condition
Other 317LM tempers and conditions
317LM is listed in 5 conditions; see the grade overview at 317LM.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault solution annealed (~1040–1120 °C, water quenched) plate/sheet | Standard stock condition for all corrosion service — maximum corrosion resistance, ductility and weldability. | 290 | 600 | 50 | 165 HB | — |
weld metal / HAZ, no post-weld heat treatment | Typical fabricated condition; low carbon avoids sensitisation, but use over-alloyed filler (ER317L or Ni-base 625) to offset Mo segregation. | 350 | 600 | 35 | 180 HB | 2.2 % IACS |
Cold Drawn / cold finished bar (annealed then lightly drawn) | Bar stock for shafts, fasteners and machined fittings needing better tolerance and higher yield than annealed. | 460 | 700 | 30 | 210 HB | — |
Quarter hard | Choose when structural strength must roughly double with only moderate loss of formability. | 600 | 900 | 20 | 25 HRC | — |
1/2 HardThis page Half hard | Highest commonly stocked cold-worked strength level for springs, clamps and strapping; forming is limited to gentle bends. | 800 | 1,070 | 14 | 32 HRC | 2.2 % IACS |
What is 317LM-1/2 Hard?
317LM-1/2 Hard is 317LM supplied in the 1/2 Hard condition — highest commonly stocked cold-worked strength level for springs, clamps and strapping; forming is limited to gentle bends. 317LM-1/2 Hard has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,070 MPa (155 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 193 GPa (28 Msi). 317LM-1/2 Hard has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F). Annealed is the default condition FabDigit quotes; 1/2 Hard is available on request or by drawing note.
Advantages
- High strength — 800 MPa (116 ksi), better than 96% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
Limitations
- Limited ductility — 14%, worse than 91% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
317LM-1/2 Hard properties
Typical room-temperature values for 317LM-1/2 Hard; 23 are specific to this condition. Other listed values are 317LM reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
317LM-1/2 Hard has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F).
Mechanical15
317LM-1/2 Hard has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,070 MPa (155 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
317LM-1/2 Hard is rated for continuous service to 300°C (572 °F). It conducts heat at 14.2 W/m·K (8.2 BTU/hr·ft·°F), worse than 76% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
317LM-1/2 Hard conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 73% of stainless steel grades.
Sustainability4
Producing a kilogram of 317LM-1/2 Hard takes about 58 MJ of energy and emits 5.2 kg of CO₂ — more than 66% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
317LM-1/2 Hard's machinability is fair (42/100, better than 79% of stainless steel grades); weldability very good (70/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 317LM-1/2 Hard
Is 317LM easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake sharp carbide, heavy constant feed, 20–35 % lower surface speed than 304, and flood high-lubricity coolant.
Can 317LM be welded?
Readily welded by GTAW/GMAW/SMAW with no pre- or post-weld heat treatment; use ER/E317L or over-alloyed Ni-base (625/C-276) filler for full weld-metal corrosion resistance and keep interpass temperature below ~150 °C.
Can 317LM be formed, bent or molded?
Cold forms well but needs ~20–30 % more force and greater springback allowance than 304; hot work at 1150–1200 °C followed by solution anneal and water quench.
What surface finishes work on 317LM?
Pickle and passivate (nitric or nitric–HF) after hot work or welding to restore the passive film; polishes to a bright mirror finish, no anodising applicable.
317LM 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, sensitisation resistant | ≤ 0.03 | 0.02 |
| Mn | ≤ 2 | 1.5 |
| Si | ≤ 0.75 | 0.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0 |
| Cr | 18 – 20 | 19 |
| Ni | 13.5 – 17.5 | 15 |
| Mo | 4 – 5 | 4.5 |
| N | ≤ 0.1 | 0.05 |
| Fe | balance | — |
317LM-1/2 Hard — frequently asked
What is 317LM-1/2 Hard used for?
317LM-1/2 Hard is typically used for pulp bleach plants, seawater equipment and chemical process piping. In short: higher-Mo 317L upgrade; chloride pitting resistance; weldable without PWHT.
What is the yield strength of 317LM-1/2 Hard?
317LM-1/2 Hard has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 1,070 MPa (155 ksi) — stronger than 96% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 317LM-1/2 Hard easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake sharp carbide, heavy constant feed, 20–35 % lower surface speed than 304, and flood high-lubricity coolant.
Can 317LM-1/2 Hard be welded?
Yes — weldability is rated very good (70/100). Readily welded by GTAW/GMAW/SMAW with no pre- or post-weld heat treatment; use ER/E317L or over-alloyed Ni-base (625/C-276) filler for full weld-metal corrosion resistance and keep interpass temperature below ~150 °C.
What surface finishes work on 317LM-1/2 Hard?
Pickle and passivate (nitric or nitric–HF) after hot work or welding to restore the passive film; polishes to a bright mirror finish, no anodising applicable.
Can 317LM-1/2 Hard be formed, bent or molded?
Cold forms well but needs ~20–30 % more force and greater springback allowance than 304; hot work at 1150–1200 °C followed by solution anneal and water quench.
What is the maximum service temperature of 317LM-1/2 Hard?
317LM-1/2 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.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A312/A312M — Seamless, Welded and Heavily Cold Worked Austenitic Stainless Steel Pipes — ASTM International (2022)
- ASTM A276/A479 — Stainless Steel Bars and Shapes — ASTM International (2022)
- ASTM A666 — Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar — ASTM International (2015)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B: Corrosion — Materials — ASM International (2005)
- 317L / 317LM / 317LMN austenitic stainless datasheets — Outokumpu / Sandvik / North American Stainless (2022)
- GB/T 24511 / GB/T 4237 (00Cr19Ni13Mo4 ) (2017)
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.