EN9 CARBON STEEL |070M55 BS970 STANDARD
EN9 Carbon steel is a medium carbon steel with 0.5-0.6% C as per BS 970 standard.It is also known as 070M55 with tensile strength between 500-800Mpa.
EN9 steel is generally supplied in untreated condition or in the normalized condition.This material can be flame or induction hardened to produce a high surface hardness with excellent wear resistance .When hardened and tempered, it develops a tensile strength in the range 700-1000 N/mm depending on ruling section.
1.EN9 steel Supply Form & Size
Hot rolled round bar:Φ20-Φ200mm,Length:3000-6000mm
Hot Forged round bar:Φ80-Φ1000mm,Length:3000-10000mm
Flat bar/Blcoks:Thickness :120-800mm xWidth:120-1500mm,Length:2000-6000mm
2.Surface Finish&Tolerance
| Surface Finish | Black-Forged | Black-Rolled | Turned | Grinding | Polished | Peeled | Cold Drawn |
| Tolerance | (0，+5mm) | (0，+1mm) | (0，+3mm) | Best h9 | Best h11 | Best H11 | Best H11 |
3.EN9 Steel Chemical Composition
| Grade | C | Mn | P | S | Si |
| EN9/070M55 | 0.5-0.6 | 0.50-0.9 | ≤ 0.05 | ≤ 0.05 | 0.1-0.4 |
4.EN9 Steel Related Specifications
- BS 970-1991:070M55
- AISI/ASTM A29:1045,1050,1055,1060
- DIN Werkstoff No.: 1.0535,1.1209
- BS & DIN European:C45, CK45,C50,C55,CK55
- JIS G4051: S45C, S50C,S55C
5.Mechanical Property For EN9 Steel
| Condition | N | R | S | T |
| Ruling Section,mm | 254 | 100 | 65 | 20 |
| Tensile Strength,Mpa | 600-700 | 690-850 | 770-930 | 850-1000 |
| Yield Strength,Mpa | ≥310 | ≥415 | ≥480 | ≥570 |
| Elongation | 13% | 14% | 14% | 12% |
| Hardness,HBW | 201-255 | 201-255 | 223-277 | 248-302 |
6.EN9 steel Forging
Forging temperature:850-1100℃,EN9 steel should be cooled as slowly as possible in still air or in sand after forged.
6.Heat Treatment For EN9 Steel
- Normalizing
The normalizing temperature range for this grade is typically 820-880ºC,followed by cooling in still air.
- Annealing
Heat slowly to 680-710°C, soak well. Cool slowly in the furnace.
- Hardening
Hardening of this grade is carried out from an austenitizing temperature of 820-850ºC followed by oil or water quenching.
- Tempering
Carbon steel EN9 or 070M55 can be tempered at a heat of between 550°C to 660°C,heating for about 1 hour for every inch of thickness, then cool in oil or water.
7.EN9 Steel Application
EN9 steel is suitable for engineering applications which require higher strength and wear resistance.Typical applications include:shafts, axes, knives, bushes, crankshafts, screws, sprockets ,springs, cylinders, cams,sickles, wood working drills,small gears, machine tools, keys and hammers.