G-I-A

G-I-B

G-I-C

G-I-D

G-II

Internal cracks

Surface cracks

C > 0.6%

C from 0.17% to 0.24%

C < 0.16 & C from

C from 0.09

0.25% to 0.6%

to 0.17%

Si > 0.5%

Mn > 1%

Mo > 0.25%

Al > 0.004%

S > 0.025

P > 0.03%

Nb from 0.02

Cr > 3%

to 0.04%

Ni > 1%

S > 0.015

V > 1%