Download a pdf version of this data sheet for printing and future reference. (right click and select save to disk) 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 .41 .30 .85   1.0 .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 .41 .25 .70 1.80 .80 .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 .31 .30 .60 2.50 .65 .50 Highly stressed shafts and gears in larger sizes. EN26 AS 1444-1996 X9940 BS970-1955 EN26 BS970 Part 3-1991 826M40 .40 .30 .60 2.50 .65 .50 As EN25 and also suitable where high surface pressure exists. Interlloy believes the information provided is accurate and reliable. However no warranty of accuracy, completeness or reliability is given, nor will any responsibility be taken for errors or omissions.