Steel EN9
BS EN9 · EN 9
EN9 is a British Standard medium-carbon manganese steel of about 0.55 % C, equivalent to AISI 1055, available hot-rolled, cold-rolled, cold-drawn, annealed, normalized, quenched and tempered or induction hardened.
Values for the HR condition
EN9 tempers and conditions
EN9 is supplied in 8 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
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 | — |
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?
EN9 is a British Standard medium-carbon manganese steel of about 0.55 % C, equivalent to AISI 1055, available hot-rolled, cold-rolled, cold-drawn, annealed, normalized, quenched and tempered or induction hardened. It is used quenched and tempered for gears, shafts, studs and similar bar-turned parts needing moderate strength; the default condition gives 340 MPa yield, 620 MPa tensile, 16 % elongation and 187 HB. Limits are no corrosion resistance and poor weldability at this carbon level. Where welded fabrication or deeper hardening is required, move to 4135/4140 or a case-hardening grade such as 16MnCr5. EN9 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). EN9 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 76% of steel grades. Elongation at break is 16% and the elastic modulus is 207 GPa (30 Msi).
What is EN9 used for?
- Crankshafts
- Shafts
- Industrial bolts
Advantages
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Low strength — 340 MPa (49.3 ksi), worse than 76% of steel grades
EN9 properties
Typical room-temperature values for EN9-HR; bars are the position among steel grades.
Physical3
EN9 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 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 76% of steel grades. Elongation at break is 16% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
EN9 is rated for continuous service to 350°C (662 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
EN9 conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of EN9 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's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (35/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. EN9 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with EN9
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.
Manufacturability
The process limits FabDigit applies to EN9. Every EN9 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better50 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better35 / 100 |
|---|---|
| Weldability | Better35 / 100 |
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 |
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.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel EN9 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 9
- BS
- 970 080M40
- Similar grades
- 1055
How much does EN9 cost?
EN9 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
EN9 — frequently asked
What is EN9 used for?
EN9 is typically used for crankshafts, shafts and industrial bolts. In short: medium-carbon English bar.
What is the yield strength of EN9?
EN9 has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 76% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is EN9 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% 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 be welded?
With care — weldability is rated fair (35/100). 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?
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 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?
EN9 is rated for continuous use to about 350°C (662 °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.
How much does EN9 cost?
EN9 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in EN9?
Yes — EN9 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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.