ELESA concave and convex washers of the DIN 6319-NI standardized series are made out of AISI 303 stainless steel and conform to the specifications of DIN 6319-C and DIN 6319-D standards. They are mostly used for locking of the mechanical parts. They are available in multiple versions with weight ranging from 3 to 640 grams, and diameters from 12 to 56 mm.