Steel EN9-IH (Induction hardened)
Heat-treated state
BS EN9 · EN 9
Best choice for shaft journals, sprocket teeth and slideways needing a hard wear surface with a tough core.
Values for the IH condition
Other EN9 tempers and conditions
EN9 is listed in 8 conditions; see the grade overview at EN9.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full/spheroidize annealed, softest condition | Pick for maximum machinability, deep cold forming or before re-hardening. | 310 | 580 | 22 | 170 HB | 10.5 % IACS |
HRDefault Hot rolled | Standard mill stock for shafting and general machined parts that will be heat treated later or used as-is at moderate load. | 340 | 620 | 16 | 187 HB | 10 % IACS |
austenitised ≈840–870 °C, air cooled | Choose for uniform fine pearlitic structure, refined grain and repeatable machining/heat-treat response. | 380 | 680 | 16 | 200 HB | 10 % IACS |
Quenched and tempered | Standard condition for loaded shafts, gears and spindles needing a tough, uniform 200–255 HB core. | 540 | 800 | 15 | 23 HRC | — |
IHThis page Induction hardened | Best choice for shaft journals, sprocket teeth and slideways needing a hard wear surface with a tough core. | 540 | 800 | 10 | 57 HRC | 9 % IACS |
Cold drawn | Use for close-tolerance, bright-finish bar where higher yield and better surface than hot rolled are wanted without heat treatment. | 570 | 720 | 11 | 18 HRC | 10 % IACS |
Cold rolled | Cold-rolled flat product for stamped springs, saw blades, blades and hardened flat components. | 600 | 750 | 9 | 20 HRC | 10 % IACS |
Quenched and low tempered (≈200–300 °C), high hardness | Pick when wear resistance and hardness (≈45–55 HRC) matter more than toughness, e.g. keys, wedges, small tooling. | 1,150 | 1,500 | 8 | 50 HRC | 8 % IACS |
What is EN9-IH?
EN9-IH is EN9 heat treated to IH — best choice for shaft journals, sprocket teeth and slideways needing a hard wear surface with a tough core. EN9-IH has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 70% of steel grades. Elongation at break is 10% and the elastic modulus is 207 GPa (30 Msi). EN9-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). HR 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
- Low fracture toughness — 30 MPa·√m (27.3 ksi·√in), worse than 96% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
EN9-IH properties
Typical room-temperature values for EN9-IH; 21 are specific to this condition. Other listed values are EN9 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
EN9-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
EN9-IH has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 70% of steel grades. Elongation at break is 10% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
EN9-IH is rated for continuous service to 200°C (392 °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
EN9-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 EN9-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
EN9-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 EN9-IH
Is EN9 easy to machine?
Machines cleanly in the annealed or normalized state (~55 % of AISI 1212); use rigid setups, carbide at 120–180 m/min, and expect tool life to fall sharply above ~250 HB.
Can EN9 be welded?
Poor weldability at 0.55 % C — preheat 200–300 °C, low-hydrogen consumables, and temper or slow-cool after welding to avoid martensitic cracking in the HAZ.
Can EN9 be formed, bent or molded?
Cold form only in the annealed condition with generous bend radii; hot forge at 1050–1200 °C and normalize afterwards to restore grain size.
What surface finishes work on EN9?
No inherent corrosion protection — oil, phosphate, black oxide, zinc plate or paint; takes a good ground/polished finish and is well suited to hard chrome on journals.
EN9 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 |
|---|---|---|
| CBS 970 070M55; suppliers quoting EN9 as 080M40 use 0.36–0.44 % C | 0.5 – 0.6 | 0.55 |
| Si | 0.05 – 0.35 | 0.2 |
| Mn | 0.5 – 0.9 | 0.7 |
| S | ≤ 0.06 | 0.03 |
| P | ≤ 0.06 | 0.03 |
| Fe | balance | — |
EN9-IH — frequently asked
What is EN9-IH used for?
EN9-IH is typically used for crankshafts, shafts and industrial bolts. In short: medium-carbon English bar.
What is the yield strength of EN9-IH?
EN9-IH has a typical yield strength of 540 MPa (78.3 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 70% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is EN9-IH easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Machines cleanly in the annealed or normalized state (~55 % of AISI 1212); use rigid setups, carbide at 120–180 m/min, and expect tool life to fall sharply above ~250 HB.
Can EN9-IH be welded?
Not readily — weldability is rated not recommended (10/100). Poor weldability at 0.55 % C — preheat 200–300 °C, low-hydrogen consumables, and temper or slow-cool after welding to avoid martensitic cracking in the HAZ.
What surface finishes work on EN9-IH?
No inherent corrosion protection — oil, phosphate, black oxide, zinc plate or paint; takes a good ground/polished finish and is well suited to hard chrome on journals.
Can EN9-IH be formed, bent or molded?
Cold form only in the annealed condition with generous bend radii; hot forge at 1050–1200 °C and normalize afterwards to restore grain size.
What is the maximum service temperature of EN9-IH?
EN9-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 EN9-HR and EN9-CR?
HR is the default condition — standard mill stock for shafting and general machined parts that will be heat treated later or used as-is at moderate load. CR: cold-rolled flat product for stamped springs, saw blades, blades and hardened flat components. Yield strength is 340 MPa in HR versus 600 MPa in CR.
Can FabDigit make parts in EN9-IH?
Yes — EN9-IH is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- BS 970-1: Wrought steels for mechanical and allied engineering purposes (070M55 / En9) — BSI (1991)
- EN 10083-2 Steels for quenching and tempering — C55 — CEN (2006)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook (machinability ratings, heat treatment of carbon steels) — Industrial Press (2020)
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.