Hardenability of Steels

A steel’s hardenability is important to consider when selecting material for your parts, as a steel with high hardenability will penetrate deeper into the cross-section of the part. Different types of steel react differently to the Jominy end-quench test, which has been the standard test since 1937. This installment of Metallurgy Minute will walk you through the differences you can expect to see when testing the hardenability of three commonly-used materials: 1040, 4140, and 4340.