ISO 7040 hexagon lock nut, M3, sst 72 h, Article number 70400033SST072. Property class / material: steel class 6, surface finish zinc plated, yellow passivated. Hexagon Lock Nut manufactured to ISO 7040 with ISO metric (M) thread, coarse pitch, fully threaded. Standard parts to the same standard, property class, dimensions and surface finish are interchangeable between manufacturers; confirm the controlling standard revision, any class-society or application approval, and the mating thread before substitution.