Steel 1137 · hardness band
Steel 1137 QT-28-32HRC
Properties of the QT-28-32HRC condition, compared with the other 1137 tempers.
Standard machine-shaft hardness band; good balance of strength, wear and remaining machinability.
What is 1137 QT-28-32HRC?
1137 QT-28-32HRC is 1137 heat treated to QT-28-32HRC — standard machine-shaft hardness band; good balance of strength, wear and remaining machinability. 1137 QT-28-32HRC has a yield strength of 790 MPa (115 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi). 1137 QT-28-32HRC 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; QT-28-32HRC is available on request or by drawing note.
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- High strength — 790 MPa (115 ksi), better than 86% of steel grades
- High electrical conductivity — 10 % IACS, better than 82% 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 — 25/100, worse than 77% of steel grades
1137 QT-28-32HRC properties
Typical room-temperature values for 1137 QT-28-32HRC — 10 properties are specific to this condition; the rest are grade-level values shared by every 1137 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
1137 QT-28-32HRC 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 QT-28-32HRC has a yield strength of 790 MPa (115 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1137 QT-28-32HRC 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 QT-28-32HRC conducts electricity at 10 % IACS, better than 82% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (9/100), worse than 98% of steel grades.
Sustainability4
Producing a kilogram of 1137 QT-28-32HRC 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 QT-28-32HRC's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (25/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 1137 tempers and conditions
1137 is also supplied in 8 other conditions. The full side-by-side table is on the 1137 overview.
- HRDefaultStandard stocked condition for large-diameter screw-machine and forging stock; lowest cost.380 MPa yield · 179 HB
- QT-33-38HRCHighest practical Q&T band for 1137 where wear resistance matters more than toughness; machine before hardening.980 MPa yield · 35 HRC
- QT-28-32HRCStandard machine-shaft hardness band; good balance of strength, wear and remaining machinability.790 MPa yield · 30 HRC
- CDMost-used bar condition for automatic-lathe parts: tight tolerance, bright finish, higher strength and better chip control.620 MPa yield · 217 HB
- QT-22-26HRCModerate-strength tough condition for shafts and studs that still need reasonable machining after heat treat.620 MPa yield · 24 HRC
- CRCold-rolled flats and special sections; properties similar to cold drawn round bar, choose for flat/hex stock with bright surface.600 MPa yield · 212 HB
- NUniform fine pearlitic structure after forging; better toughness and consistency than as-rolled at similar strength.400 MPa yield · 197 HB
- AnnealedSoftest condition; pick when maximum ductility for cold heading/bending or a stress-free blank before hardening is needed.345 MPa yield · 174 HB
Working with 1137 QT-28-32HRC
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 QT-28-32HRC — frequently asked
What is 1137 QT-28-32HRC used for?
1137 QT-28-32HRC 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 QT-28-32HRC?
1137 QT-28-32HRC has a typical yield strength of 790 MPa (115 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1137 QT-28-32HRC easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% 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 QT-28-32HRC be welded?
Not readily — weldability is rated poor (25/100). 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 QT-28-32HRC?
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 QT-28-32HRC 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 QT-28-32HRC?
1137 QT-28-32HRC 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 QT-28-32HRC?
Yes — 1137 QT-28-32HRC is available for CNC machining with instant online pricing. 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.