Left hand steel alloy worm wheel Surface :BO SGS audited More than 20 years ... hand steel alloy worm wheel;Left hand worm wheel;Steel alloy worm wheel 2,For the similar worm wheel ,what can we do ... ), Ability for the material of this kind of worm wheel: Grade3.6,4.6,4.8,5.6,6.8 ... ,8.8,9.8,10.9,12.9,etcCarbon steelGr.B,Gr.C,Gr.D,Gr ... the cutting/turning parts.; Left hand steel alloy worm wheel