This specification covers chrome-molybdenum (4140) steel bars@ rods@ and forging stock of aircraft quality. Classification: Physical conditions: Bars and rods shall be furnished in one of the following physical conditions@ as specified (see 6.2): (A) As forged (B) As rolled (C) Annealed (D) Normalized (E) Normalized and tempered (F) Quenched and tempered Surface conditions: Bars and rods shall be furnished in one of the following surface conditions@ as specified (see 6.2): (1) Black@ as forged or rolled (2) Pickled or blast cleaned (3) Rough turned (4) Cold finished (5) Turned@ ground@ and polished