Bars and billets for forging; forgings and drop-forgings; bars for machining; bright bars. Suitable for U, V, W, X, Y, Z (60/70 to 100 tons/sq in) according to ruling section.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Si
Mn
Ni
Cr
Mo
S
P
0.36-0.44
0.10-0.35
0.50-0.70
2.30-2.80
0.50-0.80
0.40-0.70
<=0.050
<=0.050
Mechanical Properties
Tensile Strength
≥927 MPa (60 tons/sq in, converted)
Yield Strength
≥741 MPa (48 tons/sq in, converted)
Elongation
≥17%
Hardness
269-321 HB
Condition
Hardened and tempered U, ruling section 6 in (lowest-strength condition of the standard)
More data from BS 970:1955
From the standard
Condition of material on delivery
A
Bars and billets for forging as rolled or forged unless order states otherwise.
B
Forgings and drop-forgings finally heat treated unless order states otherwise.
C
Bars for machining in the softened condition unless order states otherwise.
D
Bright bars finally heat treated, before or after cold work at manufacturer option, unless order states otherwise.
Source: BS 970:1955, Part 2, En 26 (page 108)
Mechanical properties
Condition
Ruling section or size (in)
Tensile strength (tons/sq in)
Yield stress (tons/sq in)
Elongation (%)
Izod impact (ft lb)
Brinell (HB)
Proof stress 0.2% (tons/sq in), when requested
Hardened and tempered U
6
60
48
17
35
269-321
46
Hardened and tempered V (ruling 6)
6
65
52
14
35
293-341
50
Hardened and tempered V (ruling 4)
4
65
52
16
35
293-341
50
Hardened and tempered W (ruling 6)
6
70
58
13
30
311-375
55
Hardened and tempered W (ruling 4)
4
70
58
15
30
311-375
55
Hardened and tempered X (ruling 6)
6
75
63
12
25
341-388
59
Hardened and tempered X (ruling 4)
4
75
63
14
25
341-388
59
Hardened and tempered Y (ruling 6)
6
80
68
12
25
363-415
64
Hardened and tempered Y (ruling 4)
4
80
68
14
25
363-415
64
Hardened and tempered Z
4
100
85
10
10
444
80
Softened condition
-
-
-
-
-
<=277
-
Values as printed in BS 970:1955; tensile strength, yield stress and proof stress in tons/sq in, Izod in ft lb. Minimum unless a range is shown.
Source: BS 970:1955, Part 2, En 26 (page 109)
Heat treatment
Harden (oil)
820/850 C
Temper
suitable temperature not exceeding 660 C
Temperatures in degrees C as printed.
Source: BS 970:1955, Part 2, En 26 (page 108)
Status in the 1955 edition
Status
Deleted by Amendment 7
Reason
Amendment 7 (Sep 1970): direct hardening alloy steels moved to BS 970 Part 2:1970
BS 970:1955 was amended up to Amendment 10 (June 1972); steels were moved to the revised Parts 1 to 5 and deleted from this edition.
Source: BS 970:1955, Amendment slips 6 to 10
Active BS 970:1955 EN26 Listings on M-EX (For Sale)