Bars and billets for forging; forgings and drop-forgings; bars for machining; bright bars. Suitable hardened and tempered for 40/50 (Q) and 45/55 (R) tons/sq in according to ruling section; purchaser to state normalised, cold drawn or hardened and tempered Q or R. When required as plate, sheet or strip order to BS 1449.
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
S
P
0.15-0.25
0.10-0.35
1.30-1.70
<=0.40
<=0.25
<=0.060
<=0.060
Mechanical Properties
Tensile Strength
≥541 MPa (35 tons/sq in, converted)
Yield Strength
≥324 MPa (21 tons/sq in, converted)
Elongation
≥20%
Hardness
152-207 HB
Condition
Normalised, 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 14A (page 70)
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
6
35
21
20
15
152-207
-
Hardened and tempered Q
4
40
28
20
30
179-229
26
Hardened and tempered R
1 1/8
45
32
20
25
201-255
30
Cold drawn
2
45
-
15
15
-
-
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 14A (page 71)
Heat treatment
Normalise (material required normalised)
860/900 C
Harden (oil or water) (material required hardened and tempered)
860/900 C
Temper (material required hardened and tempered)
suitable temperature between 550 C and 660 C
Temperatures in degrees C as printed.
Source: BS 970:1955, Part 2, En 14A (page 70)
Notes
Note
Izod for normalised 15 (30 for controlled grain steel). Brinell for R marked As altered Feb. 1963.
Source: BS 970:1955, Part 2, En 14A
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 EN14A Listings on M-EX (For Sale)