... ferrule Surface :Zn Machined and turned SGS audited More than 20 years experience in special fastener 1,Name:Metal step ferrule;step ferrule ... ;metal ferrule 2,For the similar ferrule,what can we do ?(1), ... Ability for the material of this kind of ferrule: Grade3.6,4.6,4.8,5.6,6. ... ,especially the cutting/turning parts. Metal step ferrule