BS 970 (Part 3):1991 070M20 Steel: Specifications & Listings

Maximum unless a range is stated.

Source: BS 970 (Part 3):1991, Table 13

Condition	Reference symbol	Size (mm)	Tensile strength Rm (MPa)	Yield Re, min (MPa)	Elongation, min (%)	Impact Izod, min (J)	Impact KCV, min (J)	Rp0.2, min (MPa)	Hardness HB	Notes
Normalized + turned or ground		≥ 6 ≤ 150	430 min.	215	21	—	—	—	126-179
Normalized + turned or ground		> 150 ≤ 250	400 min.	200	21	—	—	—	116-170
Hot rolled + cold drawn or hot rolled + cold drawn + ground		≥ 6 ≤ 13	560 min.	440	10	—	—	420	—
Hot rolled + cold drawn or hot rolled + cold drawn + ground		> 13 ≤ 16	530 min.	420	12	—	—	390	—
Hot rolled + cold drawn or hot rolled + cold drawn + ground		> 16 ≤ 40	490 min.	370	12	—	—	340	—
Hot rolled + cold drawn or hot rolled + cold drawn + ground		> 40 ≤ 63	480 min.	355	13	—	—	290	—
Hot rolled + cold drawn or hot rolled + cold drawn + ground		> 63 ≤ 76	450 min.	325	14	—	—	280	—

Condition letters P to Z are the tensile strength ranges of Table 29. Rp0.2 applies when specifically ordered (note 3). Hardness HB is for guidance only except in the softened condition (note 13). Impact: Izod, or KCV when the standard impact test is not required (option A.3).

Source: BS 970 (Part 3):1991, Table 20

Normalizing, hardening and tempering temperatures as given in Tables 27 and 28 (clause 4.2); Table 22 hardening temperatures for case hardening steels.

Source: BS 970 (Part 3):1991, Table 27