EN8
EN8 Grade Introduction:
EN8 is an unalloyed medium carbon steel grade with reasonable tensile strength. It is normally supplied in cold-drawn or as-rolled conditions. Tensile properties can vary but are usually between 500-800 N/mm². EN8 is widely used for applications that require better properties than mild steel but does not justify the costs of alloy steel. EN8 can be flame or induction hardened to produce a good surface hardness with moderate wear resistance. EN8 is available from stock in the bar and can be cut to your requirements. We also offer flame cut plates cut to your required sizes and normalized. EN8 plates can be supplied surface ground or precision ground.
EN8 Grade Application:
- general-purpose axles
- shafts
- gears
- bolts and studs
- automotive and general engineering components
- spindles
EN8 Equivalent Grades:
| Standard |
BS 970-1991 |
AISI/ASTM A29 |
DIN Werkstoff No. |
BS & DIN European |
JIS G4051 |
| Grade |
080M40 |
1038, 1040, 1045 |
1.0511, 1.1186, 1.1189 |
C40, CK40, C45, CK45 |
S40C, S45C |
EN8 Chemical Composition:
| Element |
C |
Si |
Mn |
P |
S |
| Content (%) |
0.36-0.44 |
0.10-0.40 |
0.60-1.00 |
0.05 |
0.005 |
Mechanical Properties:
| Heat Treatment |
Tensile Strength (Rm) |
Yield Strength (Rp 0.2) |
(Rp 0.2) |
(A min on 5.65√So) |
Izod Impact (Ft.lb) |
KCV (J) |
Hardness |
| N |
550 |
280 |
– |
16 |
15 |
16 |
152/207 |
| Q |
625/775 |
385 |
355 |
16 |
25 |
28 |
179/229 |
| R |
700/850 |
465 |
450 |
16 |
25 |
28 |
201/255 |
Thermal Properties:
| Property |
Value |
Unit |
| Thermal Conductivity |
37.5 |
W/m·K |
| Thermal Coefficient |
6.5e-6 |
1/K |
Forging Properties:
Preheat the steel carefully, then raise temperature to 1050°C for forging. Do not forge below 850°C. After forging cool slowly, preferably in a furnace.
Stress Relieving:
Stress relieving is applied to both ferrous and non-ferrous alloys and is intended to remove internal residual stresses generated by prior manufacturing processes such as machining, cold rolling and welding. Without it, subsequent processing may give rise to unacceptable distortion and/or the material can suffer from service problems such as stress corrosion cracking.