... 4. Tolerance:+/-0.0001 high quality stainless steel worm gear with good priceSpecifications:1) Suitable for various automotive, electronic, telecommunications, mechanical products ... treatment, induction hardening, carbonadoing, others optional can be as requirements6)Material: iron/aluminum, copper, alloy, carbon steel, 18CrMnTi,20CrMnTi,20Cr,20CrV ...