SAE4140 – BRIGHT BAR Grade Introduction:
SAE 4140 Alloy Steel  Round Bars are cold drawn annealed steel of comparatively superior hardenability in the company of its chromium content that offers some excellent hardness infiltration, and the molybdenum imparts consistency of soaring potency and hardness. These SAE 4140 Alloy Cold Rolled Round Bars reacts well to heat-treatment and is quite simple to machine in the annealed state. 
SAE4140 – BRIGHT BAR Equivalent grades:
USA
Din
BS
BS
Japan
ASTM A29
DIN 1654
EN 10084
BS 970
JIS G4103
4140
1.6523/21NiCrMo2
1.6523/21NiCrMo2-2
805M20
SNCM220
SAE4140 – BRIGHT BAR Chemical composition: 
The following table shows the chemical composition of SAE 4140 steel:
Standard
Grade
C
Si
Mn
S
Cr
Mo
ASTM A29
4140
0.38-0.43
0.15-0.35
0.75-1.00
0.035
0.040
0.8-1.10
0.15-0.25
EN 10250
42CrMo4 / 1.7224
0.38-0.45
0.4
0.6-0.9
0.035
0.035
0.9-1.2
0.15-0.30
JIS G4105
SCM 440
0.38-0.43
0.15-0.35
0.60-0.85
0.03
0.03
0.9-1.2
0.15-0.30