Steel 1140-IH (Induction hardened)
Heat-treated state
AISI/SAE 1140 · UNS G11400
Use when wear-resistant journal or spline surfaces are needed on a tough core.
Values for the IH condition
Other 1140 tempers and conditions
1140 is listed in 9 conditions; see the grade overview at 1140.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest, most stable condition — for deep boring, cold forming or before final hardening. | 310 | 560 | 24 | 156 HB | — |
Hot rolled | Lowest-cost condition for parts machined all over or for subsequent heat treatment. | 345 | 585 | 20 | 170 HB | — |
Normalized | Refines grain and homogenises hot-rolled bar before quench-and-temper or heavy machining. | 375 | 650 | 22 | 10 HRC | 10 % IACS |
Cold drawn, stress relieved | Use where cold-drawn strength is wanted but distortion during heavy one-side machining must be minimised. | 480 | 620 | 18 | 11 HRC | 10 % IACS |
CDDefault Cold drawn | Most stocked condition: higher yield strength, tight size tolerance and a bright, chip-friendly surface for screw-machine work. | 550 | 655 | 15 | 197 HB | — |
IHThis page Induction hardened | Use when wear-resistant journal or spline surfaces are needed on a tough core. | 580 | 800 | 10 | 54 HRC | 9 % IACS |
oil quenched, high temper (≈620 °C) | Choose for shafts needing balanced strength and toughness that will still be machined after heat treatment. | 620 | 800 | 18 | 24 HRC | — |
oil quenched, tempered ≈540 °C | Standard through-hardened condition for medium-duty shafts, pins and couplings. | 790 | 950 | 15 | 30 HRC | — |
oil quenched, tempered ≈430 °C | Highest practical strength for 1140 sections; accept low ductility and difficult machining. | 1,030 | 1,180 | 12 | 38 HRC | — |
What is 1140-IH?
1140-IH is 1140 heat treated to IH — use when wear-resistant journal or spline surfaces are needed on a tough core. 1140-IH has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 75% of steel grades. Elongation at break is 10% and the elastic modulus is 205 GPa (29.7 Msi). 1140-IH 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). CD is the default condition FabDigit quotes; IH 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 — 580 MPa (84.1 ksi), better than 75% of steel grades
Limitations
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Difficult to machine — 20/100, worse than 97% of steel grades
- Low fracture toughness — 30 MPa·√m (27.3 ksi·√in), worse than 96% of steel grades
1140-IH properties
Typical room-temperature values for 1140-IH; 22 are specific to this condition. Other listed values are 1140 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1140-IH 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).
Mechanical16
1140-IH has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 75% of steel grades. Elongation at break is 10% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1140-IH is rated for continuous service to 180°C (356 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1140-IH conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1140-IH takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 35%.
Manufacturability7
1140-IH's machinability is poor (20/100, worse than 97% of steel grades); weldability not recommended (10/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1140-IH
Is 1140 easy to machine?
Excellent free-machining behaviour (~70 % of 1212); run high speeds with positive-rake carbide, light feeds and sulfurized oil for good chip control and finish.
Can 1140 be welded?
Not recommended for structural welds — high sulfur promotes hot cracking and 0.40 % C needs 150–260 °C preheat plus post-weld stress relief; use low-hydrogen filler if unavoidable.
Can 1140 be formed, bent or molded?
Limited cold formability, especially transverse to the rolling direction; hot form at 1100–1200 °C and anneal before severe bending or heading.
What surface finishes work on 1140?
No inherent corrosion resistance — protect with oil, black oxide, phosphate, zinc or nickel plating; sulfide inclusions can leave micro-pits in high-gloss polished or plated surfaces.
1140 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 |
|---|---|---|
| CSAE J403 / ASTM A29 heat analysis | 0.37 – 0.44 | 0.4 |
| Mn | 0.7 – 1 | 0.85 |
| Sresulfurized for machinability | 0.08 – 0.13 | 0.1 |
| P | ≤ 0.04 | 0.02 |
| Sinot specified for resulfurized grades unless agreed (typ. 0.15–0.30 in Si-killed heats) | — | — |
| Fe | balance | — |
1140-IH — frequently asked
What is 1140-IH used for?
1140-IH is typically used for shafts, gears, axles and machined structural parts. In short: heat-treatable free-cutting bar; wide range of tempers; limited weldability.
What is the yield strength of 1140-IH?
1140-IH has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 75% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1140-IH easy to machine?
Not especially — machinability is rated poor (20/100, worse than 97% of steel grades). Excellent free-machining behaviour (~70 % of 1212); run high speeds with positive-rake carbide, light feeds and sulfurized oil for good chip control and finish.
Can 1140-IH be welded?
Not readily — weldability is rated not recommended (10/100). Not recommended for structural welds — high sulfur promotes hot cracking and 0.40 % C needs 150–260 °C preheat plus post-weld stress relief; use low-hydrogen filler if unavoidable.
What surface finishes work on 1140-IH?
No inherent corrosion resistance — protect with oil, black oxide, phosphate, zinc or nickel plating; sulfide inclusions can leave micro-pits in high-gloss polished or plated surfaces.
Can 1140-IH be formed, bent or molded?
Limited cold formability, especially transverse to the rolling direction; hot form at 1100–1200 °C and anneal before severe bending or heading.
What is the maximum service temperature of 1140-IH?
1140-IH is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1140-CD and 1140-A?
CD is the default condition — most stocked condition: higher yield strength, tight size tolerance and a bright, chip-friendly surface for screw-machine work. A: softest, most stable condition — for deep boring, cold forming or before final hardening. Yield strength is 550 MPa in CD versus 310 MPa in A.
Sources
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements — 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)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- Mysteel / SMM · (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.