Spyderco Endura 4 Lightweight Blue K390

The Endura 4 Lightweight features a blade crafted from K390. Manufactured by Böhler-Uddeholm, K390 MICROCLEAN is a state-of-the-art cold work tool steel produced by the particle metallurgy process. Its advanced alloy mix was specifically developed to provide the extreme wear resistance and high compressive strength needed in industrial cutting, blanking, and punching operations. Despite its toughness, its exceptionally fine, homogeneous microstructure also makes it readily machinable and easy to heat treat. Collectively, these qualities make K390 an outstanding blade material for true steel connoisseurs.