Steel 1144-IH (Induction hardened)
Heat-treated state
AISI/SAE 1144 · UNS G11440 · EN 1.0727, 44SMn28 · also Stressproof
For shafts and pins needing a wear-resistant, fatigue-strong skin over a tough cold-drawn core.
Values for the IH condition
Other 1144 tempers and conditions
1144 is listed in 8 conditions; see the grade overview at 1144.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
spheroidize/full annealed bar | Softest condition; choose for deep machining, cold forming or before hardening. | 345 | 585 | 20 | 167 HB | — |
HRDefault Hot rolled | Lowest-cost stock size for parts that will be fully machined or later heat treated. | 400 | 670 | 15 | 13 HRC | 9.5 % IACS |
austenitized ~900 °C, air cooled | Use to refine grain and homogenize structure after hot working, before machining or hardening. | 420 | 670 | 21 | 13 HRC | 9.5 % IACS |
Cold rolled | Cold-reduced flat/shaped stock where a bright, dimensionally accurate as-supplied surface is needed. | 600 | 700 | 10 | 17 HRC | 9.5 % IACS |
Cold drawn | Standard cold-finished bar: tighter tolerance, bright surface and higher yield than hot rolled. | 620 | 705 | 10 | 212 HB | — |
IHThis page Induction hardened | For shafts and pins needing a wear-resistant, fatigue-strong skin over a tough cold-drawn core. | 655 | 790 | 10 | 54 HRC | 8.5 % IACS |
Cold Drawn, Stress Relieved | Pick when a machined shaft must stay straight after heavy stock removal and needs ~690 MPa yield without heat treatment. | 690 | 790 | 12 | 21 HRC | — |
quenched and tempered | Oil quench from ~845 °C and temper ~540 °C when higher core strength and wear resistance are required. | 830 | 965 | 13 | 30 HRC | — |
What is 1144-IH?
1144-IH is 1144 heat treated to IH — for shafts and pins needing a wear-resistant, fatigue-strong skin over a tough cold-drawn core. 1144-IH has a yield strength of 655 MPa (95 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 79% of steel grades. Elongation at break is 10% and the elastic modulus is 205 GPa (29.7 Msi). 1144-IH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). HR 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 — 655 MPa (95 ksi), better than 79% of steel grades
Limitations
- Difficult to weld — 8/100, worse than 99% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- Hard to polish — 40/100, worse than 96% of steel grades
- Difficult to machine — 22/100, worse than 95% of steel grades
- Low fracture toughness — 35 MPa·√m (31.9 ksi·√in), worse than 94% of steel grades
1144-IH properties
Typical room-temperature values for 1144-IH; 22 are specific to this condition. Other listed values are 1144 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1144-IH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
1144-IH has a yield strength of 655 MPa (95 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 79% of steel grades. Elongation at break is 10% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
1144-IH is rated for continuous service to 200°C (392 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), better than 75% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1144-IH conducts electricity at 8.5 % IACS, better than 63% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1144-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%.
Manufacturability6
1144-IH's machinability is poor (22/100, worse than 95% of steel grades); weldability not recommended (8/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1144-IH
Is 1144 easy to machine?
One of the best-machining medium carbon steels (~80 % of 1212): high speeds, chip-breaking MnS inclusions, long tool life; keep feeds up to avoid rubbing.
Can 1144 be welded?
Not recommended — 0.44 C plus 0.3 % S invites hot cracking and porosity; if unavoidable, preheat 200–300 °C, low-hydrogen filler and post-weld stress relief.
Can 1144 be formed, bent or molded?
Poor cold formability, especially transverse; bend only in the annealed condition with generous radii, or hot form at 1050–1200 °C.
What surface finishes work on 1144?
Rusts readily — specify black oxide, phosphate + oil, zinc or hard chrome plating; MnS stringers limit mirror polishing and can leave pits after plating.
1144 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 grade 1144 | 0.4 – 0.48 | 0.44 |
| Mn | 1.35 – 1.65 | 1.5 |
| SMnS inclusions give free-machining behaviour | 0.24 – 0.33 | 0.28 |
| P | ≤ 0.04 | 0.02 |
| Sinot normally specified for resulfurized grades | ≤ 0.1 | 0.05 |
| Fe | balance | — |
1144-IH — frequently asked
What is 1144-IH used for?
1144-IH is typically used for shafts, industrial spindles and cam followers. In short: resulfurized machining bar.
What is the yield strength of 1144-IH?
1144-IH has a typical yield strength of 655 MPa (95 ksi) and a tensile strength of 790 MPa (115 ksi) — stronger than 79% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 1144-IH easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of steel grades). One of the best-machining medium carbon steels (~80 % of 1212): high speeds, chip-breaking MnS inclusions, long tool life; keep feeds up to avoid rubbing.
Can 1144-IH be welded?
Not readily — weldability is rated not recommended (8/100). Not recommended — 0.44 C plus 0.3 % S invites hot cracking and porosity; if unavoidable, preheat 200–300 °C, low-hydrogen filler and post-weld stress relief.
What surface finishes work on 1144-IH?
Rusts readily — specify black oxide, phosphate + oil, zinc or hard chrome plating; MnS stringers limit mirror polishing and can leave pits after plating.
Can 1144-IH be formed, bent or molded?
Poor cold formability, especially transverse; bend only in the annealed condition with generous radii, or hot form at 1050–1200 °C.
What is the maximum service temperature of 1144-IH?
1144-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 1144-HR and 1144 CD-SR?
HR is the default condition — lowest-cost stock size for parts that will be fully machined or later heat treated. CD-SR: pick when a machined shaft must stay straight after heavy stock removal and needs ~690 MPa yield without heat treatment. Yield strength is 400 MPa in HR versus 690 MPa in CD-SR.
Can FabDigit make parts in 1144-IH?
Yes — 1144-IH 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
- ASTM A29/A29M Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- SAE J403 Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- SAE J1397 Estimated Mechanical Properties of Steel Bars — SAE International (2009)
- EN 10087 Free-cutting steels (44SMn28, 1.0727) — CEN (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- Stressproof cold drawn stress relieved bar data — Niagara LaSalle / bar producers (2022)
- GB/T 8731 (Y45Mn) — 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.