Steel 1137-SR (Stress relieved)
Heat-treated state
AISI/SAE 1137 · UNS G11370
Cold drawn then ~500 °C stress relief to reduce distortion during heavy one-side machining; slightly lower yield than plain CD.
Values for the SR condition
Other 1137 tempers and conditions
1137 is listed in 9 conditions; see the grade overview at 1137.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full anneal ~790 °C, furnace cooled | Softest condition; pick when maximum ductility for cold heading/bending or a stress-free blank before hardening is needed. | 345 | 585 | 28 | 174 HB | — |
HRDefault Hot rolled | Standard stocked condition for large-diameter screw-machine and forging stock; lowest cost. | 380 | 620 | 15 | 179 HB | — |
Normalized | Uniform fine pearlitic structure after forging; better toughness and consistency than as-rolled at similar strength. | 400 | 670 | 22 | 197 HB | — |
SRThis page Stress relieved | Cold drawn then ~500 °C stress relief to reduce distortion during heavy one-side machining; slightly lower yield than plain CD. | 550 | 690 | 13 | 14 HRC | 10 % IACS |
Cold rolled | Cold-rolled flats and special sections; properties similar to cold drawn round bar, choose for flat/hex stock with bright surface. | 600 | 705 | 11 | 16 HRC | 10 % IACS |
Cold drawn | Most-used bar condition for automatic-lathe parts: tight tolerance, bright finish, higher strength and better chip control. | 620 | 725 | 10 | 217 HB | — |
water/oil quench + high temper (~620 °C) | Moderate-strength tough condition for shafts and studs that still need reasonable machining after heat treat. | 620 | 810 | 22 | 24 HRC | — |
quench + temper ~540 °C | Standard machine-shaft hardness band; good balance of strength, wear and remaining machinability. | 790 | 965 | 17 | 30 HRC | — |
quench + temper ~430–480 °C | Highest practical Q&T band for 1137 where wear resistance matters more than toughness; machine before hardening. | 980 | 1,150 | 13 | 35 HRC | 9 % IACS |
What is 1137-SR?
1137-SR is 1137 heat treated to SR — cold drawn then ~500 °C stress relief to reduce distortion during heavy one-side machining; slightly lower yield than plain CD. 1137-SR has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 71% of steel grades. Elongation at break is 13% and the elastic modulus is 205 GPa (29.7 Msi). 1137-SR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Easy to machine — 72/100, better than 97% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
1137-SR properties
Typical room-temperature values for 1137-SR; 22 are specific to this condition. Other listed values are 1137 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1137-SR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical13
1137-SR has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 71% of steel grades. Elongation at break is 13% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1137-SR is rated for continuous service to 400°C (752 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1137-SR conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (9/100), worse than 98% of steel grades.
Sustainability4
Producing a kilogram of 1137-SR takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 40%.
Manufacturability7
1137-SR's machinability is very good (72/100, better than 97% of steel grades); weldability poor (20/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1137-SR
Is 1137 easy to machine?
Excellent free-cutting behaviour (≈70–72 % of 1212); MnS breaks chips, run high feeds with carbide and sulfur-bearing cutting oil.
Can 1137 be welded?
Not recommended — high sulfur plus 0.35 %C causes hot cracking and porosity; if unavoidable, preheat 200–260 °C, low-hydrogen filler, post-weld stress relief.
Can 1137 be formed, bent or molded?
Poor transverse cold formability due to sulfide stringers; bend along the rolling direction with generous radii or hot form at 1000–1200 °C.
What surface finishes work on 1137?
Rusts quickly — protect with oil, phosphate, black oxide, zinc or chrome plating; can be induction hardened or nitrided for wear surfaces, but poor for mirror polishing.
1137 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 | 0.32 – 0.39 | 0.36 |
| Mn | 1.35 – 1.65 | 1.5 |
| Sresulfurized for free machining | 0.08 – 0.13 | 0.1 |
| P | ≤ 0.04 | 0.02 |
| Sinot specified in SAE J403 for resulfurized grades; typical killed-steel level | ≤ 0.3 | 0.2 |
| Fe | balance | — |
1137-SR — frequently asked
What is 1137-SR used for?
1137-SR is typically used for screw machine parts, shafts and axles, studs, bolts and threaded components, pins and bushings, couplings and collars and induction-hardened gears and splines. In short: resulfurized machining bar.
What is the yield strength of 1137-SR?
1137-SR has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 71% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1137-SR easy to machine?
Yes — machinability is rated very good (72/100, better than 97% of steel grades). Excellent free-cutting behaviour (≈70–72 % of 1212); MnS breaks chips, run high feeds with carbide and sulfur-bearing cutting oil.
Can 1137-SR be welded?
Not readily — weldability is rated poor (20/100). Not recommended — high sulfur plus 0.35 %C causes hot cracking and porosity; if unavoidable, preheat 200–260 °C, low-hydrogen filler, post-weld stress relief.
What surface finishes work on 1137-SR?
Rusts quickly — protect with oil, phosphate, black oxide, zinc or chrome plating; can be induction hardened or nitrided for wear surfaces, but poor for mirror polishing.
Can 1137-SR be formed, bent or molded?
Poor transverse cold formability due to sulfide stringers; bend along the rolling direction with generous radii or hot form at 1000–1200 °C.
What is the maximum service temperature of 1137-SR?
1137-SR is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1137-HR and 1137-CD?
HR is the default condition — standard stocked condition for large-diameter screw-machine and forging stock; lowest cost. CD: most-used bar condition for automatic-lathe parts: tight tolerance, bright finish, higher strength and better chip control. Yield strength is 380 MPa in HR versus 620 MPa in CD.
Can FabDigit make parts in 1137-SR?
Yes — 1137-SR is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- SAE J1397 — Estimated Mechanical Properties of Steel Bars — SAE International (2018)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASTM A108 — Steel Bar, Carbon and Alloy, Cold-Finished — ASTM (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
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.