Technical Datasheet
EN8D
EN8D Bright Bar
Medium Carbon Steel
Kalika Enterprises
Bright Bar Manufacturer
Plot No. 12/1, Gut No. 182, Jogeshwari, MIDC Waluj, Chhatrapati Sambhajinagar, Maharashtra 431136, India
+91 94229 27509 · kalikaent9@gmail.com
EN8 held to tighter limits — for parts where batch-to-batch variation costs money. EN8D is not a different steel from EN8. It is the same medium carbon steel supplied to a tighter specification: narrower carbon and manganese bands, and phosphorus and sulphur each capped at 0.035% instead of 0.050%.
Also known as: 080A42 · AISI 1042
Key advantage
Consistent hardness batch after batch
Tighter carbon and manganese bands plus lower P and S give a narrower as-quenched hardness spread and cleaner steel. Heat treatment settings stay valid from lot to lot, and fatigue performance improves — the reason EN8D is specified for rotating parts.
Chemical composition
BS 970 Part 1 : 080A42, certified per mill test certificate
| Element | Min % | Max % |
|---|---|---|
| C Carbon | 0.410 | 0.450 |
| Si Silicon | 0.050 | 0.350 |
| Mn Manganese | 0.700 | 0.900 |
| P Phosphorus | — | 0.040 |
| S Sulphur | — | 0.040 |
Mechanical properties
Cold Drawn
| Property | Value |
|---|---|
| Tensile Strength | 620 – 780 MPa |
| Yield Strength | 470 – 550 MPa |
| Elongation (A5) | 10 – 16% |
| Hardness | 180 – 235 HB |
| Impact (Izod) | 30 J typical |
Available sizes and tolerances
| Shape | Size range |
|---|---|
| Round | 6 – 65 mm |
| Hex (AF) | 7 – 46 mm |
| Tolerance | h9 / h10 / h11 |
| Standard lengths | 3, 4, 5, 6 metre or cut to size |
ISO 286 tolerance values (µm)
| Size (mm) | h9 | h10 | h11 |
|---|---|---|---|
| over 6 to 10 | −36 | −58 | −90 |
| over 10 to 18 | −43 | −70 | −110 |
| over 18 to 30 | −52 | −84 | −130 |
| over 30 to 50 | −62 | −100 | −160 |
| over 50 to 80 | −74 | −120 | −190 |
Typical applications
- Hardened and tempered shafts
- Hydraulic piston rods and cylinders
- Automotive linkages and pins
- Fatigue loaded rotating components
- Precision machine spindles
International equivalents
| BS (UK) | 080A42 / EN8D |
| AISI / SAE (USA) | 1042 |
| DIN (Germany) | C45 / 1.0503 (nearest) |
| JIS (Japan) | S43C |
| IS (India) | 40C8 / 45C8 |
Heat treatment guidelines
| Operation | Parameters |
|---|---|
| Normalising | 830 – 860 °C, cool in still air |
| Hardening | 820 – 860 °C, quench in oil |
| Tempering | 550 – 660 °C, air cool |
| Stress relieving | 550 – 650 °C after heavy machining, to control distortion |
Machinability index
60 Moderate
Relative to AISI 1212 = 100
Weldability
Fair
Supply condition
Cold Drawn