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
Cr
S
P
0.16-0.21
0.10-0.35
0.60-0.80
0.60-0.80
<=0.050
<=0.050
More data from BS 970:1955
From the standard
Condition of material on delivery
A
Bars and billets for forging as rolled or forged.
B
Forgings and drop-forgings as forged.
C
Bars for machining as rolled.
D
Bright bars cold worked, condition suitable for machining; max Brinell may be agreed.
Source: BS 970:1955, Part 2, En 207 (page 189)
Heat treatment
Blank carburise
880/930 C
Refine
870/900 C, cool in air, oil or water
Harden (water)
760/780 C
Temperatures in degrees C as printed.
Source: BS 970:1955, Part 2, En 207 (page 189)
Notes
Note
See Appendix A for single quench treatment. No mechanical properties.
Source: BS 970:1955, Part 2, En 207
Status in the 1955 edition
Status
Deleted by Amendment 8
Reason
Amendment 8 (Jul 1971): alloy case hardening steels moved to BS 970 Part 3:1971
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 EN207 Listings on M-EX (For Sale)