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
0.25-0.35
<=0.50
1.20-1.50
0.50-1.00
0.30-0.60
0.15-0.25
<=0.050
<=0.050
Mechanical Properties
Tensile Strength
≥695 MPa (45 tons/sq in, converted)
Yield Strength
≥525 MPa (34 tons/sq in, converted)
Elongation
≥22%
Hardness
201-255 HB
Condition
Hardened and tempered R, 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 finally heat treated 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 100E (page 176)
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 R
6
45
34
22
40
201-255
32
Hardened and tempered S
4
50
38
20
40
223-277
36
Hardened and tempered T
2 1/2
55
44
18
40
248-302
41
Hardened and tempered U
1 1/8
60
48
17
35
269-321
46
Hardened and tempered V
1 1/8
65
52
16
35
293-341
50
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 100E (page 177)
Heat treatment
Harden (oil) (En 100E may be hardened in water if suitable precautions are taken; when parts to En 100E are water quenched this shall be stated on the order and test bars similarly heat treated.)
830/860 C
Temper
suitable temperature between 550 C and 660 C
Temperatures in degrees C as printed.
Source: BS 970:1955, Part 2, En 100E (page 177)
Notes
Note
For small ruling sections or lower tensile ranges, or when the steel is to be hardened in water, carbon by agreement shall be 0.25/0.35 per cent and the steel is designated En 100E.
Source: BS 970:1955, Part 2, En 100E
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 EN100E Listings on M-EX (For Sale)