BS970 817M40T EN24T

BS970 817M40T/EN24T

817M40 /EN24T is a popular through hardening 1.1 /2% Nickel Chromium Molybdenum alloy steel which is supplied in the bright drawn, turned and hot rolled condition. It is also available in forged block form which can be cold sawn to size. 817M40T / EN24T is readily machineable in the hardened and Tempered “T” condition and offers good tensile, ductility and wear resistance properties, suitable for the manufacture of axles, gears, pins and studs.

817M40T / EN24T

BS970: 1955 BS970: 1991 Description
EN24T 817M40T Bright/Black 1.1/2% nickel chromium molybdenum steel
Chemical Analysis
Car 0.36/0.44
Si 0.10/0.40
Mang 0.45/0.70
Phos 0.035 max
Sul 0.040 max
Moly 0.20/0.35
Nick 1.30/1.70
Mechanical Properties
Tensile Strength N/MM2 Min Rm 850/1000
Yield Stress NIMM2 Min Rm 700
Elongation A Min% on 5.65√SO 9
Izod Min 54
Kcv Min -
Proof Stress 0.2% N/MM2 Min 680
Brinell Hardness 248/302
International Specification Comparison
BS 970:1991 817M40T
BS 970: 1955 EN24T
German Din 34NiCrMo6
French Afnor 35NCD6
Swedish SS 2541
American SAE 4340
European Steel No 1.6582
European Steel Name 34CrNiMo6
European Standard EN10277-5
Quick View System
Machineability 40
Weldability Pre / post heat precaution required
Hardenability High strength up to 100mm dia
Selection Guide and Usage Examples Popular direct hardening steel with good tensile. ductility, shock and wear resistance properties
Size Range Summary
Rounds IMP 3/8" -3" dia
MM 10mm -310mm dia