Available in metric sizes, GN 6319.1 Steel and Stainless Steel Spherical Washers, Seat and Dished Combined Type, provide undetachable combination of male and female washers similar to DIN 6319. Steel washers are case hardened all round, with depth from .2–4 mm and hardness of (550 + 100) HV 10. Stainless steel versions, used for clamping in corrosion-free environments, are European standard 1.4305 (American standard 303 series).