This hex nut is manufactured to ISO 4032 standards from 25CrMo4+QT (1.7218) steel. It features an electrolytically zinc-plated finish, making it suitable for indoor use or applications with very mild environmental exposure. The nut has metric threading and is PED-approved (Pressure Equipment Directive) for use in pressure vessels. An EN 10204 3.1 certificate is available upon request for an additional fee.