Steel 1145-IH (Induction hardened)
Heat-treated state
AISI/SAE 1145 · UNS G11450
Use when only bearing or wear surfaces must be hard (55–60 HRC) while the core stays tough and machinable.
Values for the IH condition
Other 1145 tempers and conditions
1145 is listed in 9 conditions; see the grade overview at 1145.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest state for maximum dimensional stability, deep drilling and any limited cold forming or heading. | 310 | 570 | 22 | 163 HB | — |
Hot rolled | Cheapest form for large-diameter turned parts where the as-rolled surface will be machined away. | 325 | 585 | 18 | 170 HB | — |
Normalized | Uniform fine pearlitic structure before machining or hardening; better and more consistent properties than as-rolled. | 375 | 640 | 20 | 187 HB | — |
Cold drawn, stress relieved | Pick when unbalanced machining (keyways, deep slots) would otherwise bow the part after cutting. | 530 | 640 | 15 | 10 HRC | 10 % IACS |
IHThis page Induction hardened | Use when only bearing or wear surfaces must be hard (55–60 HRC) while the core stays tough and machinable. | 560 | 700 | 12 | 57 HRC | 9 % IACS |
CDDefault Cold drawn | Default stocked condition: straight, size-accurate bright bar with raised strength and good chip control for CNC turning. | 565 | 655 | 12 | 187 HB | — |
quenched and tempered (high temper) | Tough general-purpose hardened condition for shafts and levers that still need drilling and tapping after heat treatment. | 690 | 830 | 17 | 24 HRC | — |
quenched and tempered (medium temper) | Most common hardened spec for medium-duty gears, spindles and hydraulic parts needing strength with some machinability. | 820 | 965 | 15 | 30 HRC | — |
quenched and tempered (low temper) | Highest practical through-hardened strength for this grade; accept reduced toughness and harder machining. | 950 | 1,100 | 12 | 34 HRC | — |
What is 1145-IH?
1145-IH is 1145 heat treated to IH — use when only bearing or wear surfaces must be hard (55–60 HRC) while the core stays tough and machinable. 1145-IH has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 73% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). 1145-IH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F). CD is the default condition FabDigit quotes; IH is available on request or by drawing note.
Limitations
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- Difficult to machine — 15/100, worse than 98% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
1145-IH properties
Typical room-temperature values for 1145-IH; 23 are specific to this condition. Other listed values are 1145 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1145-IH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F).
Mechanical13
1145-IH has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 73% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1145-IH is rated for continuous service to 200°C (392 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1145-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 1145-IH takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
1145-IH's machinability is poor (15/100, worse than 98% 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 1145-IH
Is 1145 easy to machine?
Excellent turning/drilling at ~70 % of 1212 — run high surface speeds with sharp carbide, positive rake and good coolant; sulfides give clean chip break and fine finish.
Can 1145 be welded?
Avoid where possible: 0.45 %C plus 0.04–0.07 %S cause hot cracking and hard HAZ; if unavoidable preheat 200–300 °C, use low-hydrogen filler and post-weld stress relief.
Can 1145 be formed, bent or molded?
Only modest cold bending in annealed or hot-rolled condition; hot forge 1100–1230 °C and slow cool or normalize afterwards — do not cold form heavily in the cold-drawn state.
What surface finishes work on 1145?
No inherent corrosion protection — specify black oxide, phosphate + oil, zinc or hard chrome; sulfide stringers can leave micro-pits after polishing or plating.
1145 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/AISI 1145 per SAE J403 / ASTM A29 | 0.42 – 0.49 | 0.46 |
| Mn | 0.7 – 1 | 0.85 |
| P | ≤ 0.04 | 0.02 |
| Sresulfurized for machinability | 0.04 – 0.07 | 0.06 |
| Sinot specified for hot-rolled bar; 0.15–0.35 typical when ordered as killed steel | ≈ 0.22 | 0.22 |
| Fe | balance | — |
1145-IH — frequently asked
What is 1145-IH used for?
1145-IH is typically used for shafts, axles and high-strength fasteners. In short: highest-carbon 11xx bar; between 1144 and 1146; strength over weldability.
What is the yield strength of 1145-IH?
1145-IH has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 1145-IH easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Excellent turning/drilling at ~70 % of 1212 — run high surface speeds with sharp carbide, positive rake and good coolant; sulfides give clean chip break and fine finish.
Can 1145-IH be welded?
Not readily — weldability is rated not recommended (10/100). Avoid where possible: 0.45 %C plus 0.04–0.07 %S cause hot cracking and hard HAZ; if unavoidable preheat 200–300 °C, use low-hydrogen filler and post-weld stress relief.
What surface finishes work on 1145-IH?
No inherent corrosion protection — specify black oxide, phosphate + oil, zinc or hard chrome; sulfide stringers can leave micro-pits after polishing or plating.
Can 1145-IH be formed, bent or molded?
Only modest cold bending in annealed or hot-rolled condition; hot forge 1100–1230 °C and slow cool or normalize afterwards — do not cold form heavily in the cold-drawn state.
What is the maximum service temperature of 1145-IH?
1145-IH is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1145-CD and 1145-A?
CD is the default condition — default stocked condition: straight, size-accurate bright bar with raised strength and good chip control for CNC turning. A: softest state for maximum dimensional stability, deep drilling and any limited cold forming or heading. Yield strength is 565 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)
- GB/T 8731 — (free-cutting structural steel, Y45 comparison) — SAC (2008)
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.