... washer Surface :Zn(Rohs) Machined and turned SGS audited More than 20 years experience in special fastener 1,Name: Internal tooth washer ... ;Internal washer;Tooth washer2,For the similar washer,what can we do ?(1), ... Ability for the material of this kind of washer: Grade3.6,4.6,4.8,5.6,6 ... ,especially the cutting/turning parts. Internal tooth washer