This specification covers chrome-molybdenum (4130) steel bars and forging stock of aircraft quality.

Classification:

The steel bars and reforging stock shall be as follows:

Physical condition: Materials shall be furnished in one of the following physical conditions, as specified (see 6.2c):

a. As forged

b. As rolled

c. Annealed

d. Normalized

e. Normalized and tempered

f. Hardened and tempered

Surface conditions: Materials shall be furnished in one of the following surface conditions, as specified (see 6.2c):

1. Black, as forged or rolled

2. Pickled or blast cleaned

3. Rough turned

4. Cold finished (drawn)

5. Turned, ground and polished