Material: Steel, bright turned, case hardened, hardening depth min. 0.2 mm.
Spherical washers according to the old standard DIN 6319 type C are mostly used with conical seats DIN 6319 type D, for screw fittings at non-parallel faces. Conical seats DIN 6319 type G, with larger outside diameter and height, should be used at relatively big holes or slot holes.