Bars and billets for forging; forgings and drop-forgings; bars for machining; bright bars. Suitable hardened and tempered for 45/55 (R) and 50/60 (S) tons/sq in according to ruling section; purchaser to state normalised, cold drawn or hardened and tempered R or S. En 43A to 43E.
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
S
P
0.45-0.55
0.05-0.35
0.70-1.00
<=0.060
<=0.060
Mechanical Properties
Tensile Strength
≥618 MPa (40 tons/sq in, converted)
Yield Strength
≥324 MPa (21 tons/sq in, converted)
Elongation
≥18%
Hardness
179-229 HB
Condition
Normalised, ruling section 1 1/8 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 condition stated on the order.
D
Bright bars in the condition stated on the order.
Source: BS 970:1955, Part 2, En 43A (page 146)
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
Normalised
1 1/8
40
21
18
-
179-229
-
Hardened and tempered R
2
45
30
18
-
201-255
28
Hardened and tempered S
1 1/8
50
33
18
-
223-277
31
Cold drawn
2
45-60
-
12
-
201-277
-
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 43A (page 147)
Heat treatment
Normalise (material required normalised)
810/840 C
Harden (oil) (material required hardened and tempered)
810/840 C
Temper (material required hardened and tempered)
550/660 C
Temperatures in degrees C as printed.
Source: BS 970:1955, Part 2, En 43A (page 146)
Status in the 1955 edition
Status
Deleted by Amendment 9
Reason
Amendment 9 (Feb 1972): carbon and carbon-manganese steels moved to BS 970 Part 1:1972
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 EN43A Listings on M-EX (For Sale)