High Tensile Steels

Interlloy Grade Nearest Related Specification Typical Composition (%) & Properties Description & Applications
C Si Mn Ni Cr Mo
4140 AS1444-1996 4140
BS970-1955 EN19A
BS970 Part 3-1991 709M40
ASTM A29/29M 1991 4140
SAE/AISI 4140
0.41 0.30 0.85 1.0 0.20 General purpose high tensile steel for components, such as axles, shafts, bolts, gears and drill rods.

4340 AS1444-1996 4340
BS970-1955 EN24
BS970 Part 3-1991 817M40
ASTM A29/29M 1991 4340
SAE/AISI 4340
0.41 0.25 0.70 1.80 0.80 0.25 Highly stressed components such as gears. Alternative to EN25, EN26 in smaller sizes.

EN25 AS1444-1996 X9931
BS970-1955 EN25
BS970 Part 3-1991 826M31
0.31 0.30 0.60 2.50 0.65 0.50 Highly stressed shafts and gears in larger sizes.

EN26 AS 1444-1996 X9940
BS970-1955 EN26
BS970 Part 3-1991 826M40
0.40 0.30 0.60 2.50 0.65 0.50 As EN25 and also suitable where high surface pressure exists.