EN9 is a plain high-carbon steel with 0.50–0.60% carbon and 0.50–0.90% manganese, and no deliberate alloying. It gives more hardness and wear resistance than EN8 without the cost of an alloy steel. Typical uses are wear plates and blades, cams and rollers, induction-hardened gears, agricultural tools and light-duty springs.
OneKaizen sources EN9 from India's leading mills and international partner mills and supplies it as rolled round bars in Ø 16–500 mm, bright bars in Ø 8–160 mm, forged bars in Ø 250–1,030 mm and square bars in 20–480 mm. Delivery condition is your choice: hot rolled, normalised or annealed. Every consignment ships with a mill test certificate.
EQUIVALENT GRADES
EN9 Equivalents
Direct means the same grade under another name. Close means the same alloy concept with slightly different limits, commonly substituted. Approximate means similar use with real differences: check with us before substituting.
| Standard | Designation | Match |
|---|---|---|
| Old BS EN | EN9 | Direct |
| BS 970 | 070M55 | Direct |
| IS | 55C8 | Approximate |
| EN | C55E (1.1203) | Close |
| EN | C55 (1.0535) | Close |
| AISI/SAE | 1055 | Close |
| JIS | S55C | Close |
| GB | 55 | Close |
EN9 Chemical Composition
Per BS 970-1:1983 (070M55, EN9)
| Element | Range, wt % | Range chart |
|---|---|---|
| C | 0.5 – 0.6 | |
| Si | 0.1 – 0.4 | |
| Mn | 0.5 – 0.9 | |
| P | ≤ 0.05 | |
| S | ≤ 0.05 |
EN9 and Its Equivalents: Chemical Composition
Equivalent grades are written to different standards, so their limits differ slightly. Use the column for the standard on your drawing or purchase order.
| Element | 070M55 (EN9) BS 970-1:1983 | C55E EN 10083-2 | 1055 SAE J403 | S55C JIS G4051 |
|---|---|---|---|---|
| C % | 0.50–0.60 | 0.52–0.60 | 0.50–0.60 | 0.52–0.58 |
| Si % | 0.10–0.40 | ≤ 0.40 | – | 0.15–0.35 |
| Mn % | 0.50–0.90 | 0.60–0.90 | 0.60–0.90 | 0.60–0.90 |
| P % | ≤ 0.05 | ≤ 0.025 | ≤ 0.04 | ≤ 0.03 |
| S % | ≤ 0.05 | ≤ 0.035 | ≤ 0.05 | ≤ 0.035 |
Delivery Condition and Heat Treatment
EN9 is supplied hot rolled, normalised or annealed. Annealed bar is the easiest to machine; normalised bar gives a uniform structure and higher strength. Typical practice is to harden from about 810–840 °C, quench in oil or water as the section allows, then temper to the hardness you need.
EN9 is a shallow-hardening steel, so hardening is best suited to small sections or to surface hardening by induction or flame, for example on cam lobes and gear teeth. If you need uniform hardness through a larger section, move up to an alloy grade such as EN19.
Weldability is poor. Carbon at 0.50–0.60% makes the weld zone hard and crack-prone, so welding needs high preheat and stress relief. We recommend machining the part rather than welding it.
What We Supply EN9 In
Where EN9 Is Used
Industries: General engineering, Agricultural equipment, Material handling
Compare EN9 with Similar Grades
EN9 Questions
What is the difference between EN8 and EN9?
EN9 (070M55) has 0.50–0.60% carbon against 0.36–0.44% for EN8. It is harder and stronger after heat treatment, but less ductile and harder to machine. Use EN8 for general shafts and studs; use EN9 where wear resistance matters.
Is EN9 the same as 1055 or C55E?
No, they are close but not identical. SAE 1055 and C55E (1.1203) are the same alloy concept, and C55E adds tighter phosphorus and sulphur limits than the 0.05% maximum in EN9. In most uses they are interchangeable; tell us if your drawing specifies C55E.
Is EN9 the same as IS 55C8?
55C8 is only an approximate match. Send us your drawing if the Indian standard designation is called out, and we will confirm the grade before supply.
What hardness can EN9 reach?
It depends on section size and tempering temperature. As a rule of thumb, small sections quenched and tempered reach the mid-50s HRC, and induction-hardened surfaces can go higher. Tell us the hardness you need and we supply it in that condition.
Can EN9 be welded?
Not easily. The high carbon content makes the heat-affected zone hard and brittle, so welding needs preheat and stress relief. A low-carbon grade is the better choice for welded parts.
What is the minimum order for EN9 bars?
3 tonnes, flexible depending on grade, size and your situation. Round bars, bright bars, forged bars and square bars are supplied on request; send us your size, condition and quantity.
What is EN9 equivalent to?
EN9 is the same grade as Old BS EN EN9, BS 970 070M55. Close equivalents are AISI/SAE 1055, EN C55E, EN C55, JIS S55C, GB 55.
In which forms do you supply EN9?
OneKaizen supplies EN9 as Round Bars, Bright Bars, Forged Bars, Square Bars, delivered across India and exported to buyers abroad.
Do you supply EN9 with a mill test certificate?
Yes. Every lot ships with an EN 10204 3.1 mill test certificate showing chemistry and mechanical properties, traceable to the heat number.
Data compiled by the OneKaizen metallurgy team from the standards named above. Updated 26 October 2026. Equivalents are nearest matches; confirm critical substitutions against the governing standard and mill certificate.