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.

EN9 Carbon Steel | 070M55 BS970 Standard

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.