... :6-7.0mm 3Without heat treatment 4Factory supply directly 5Sprocket with A3,45#steel 16-year history, professional sprocket manufacturerself-marketing ... card, Slide blister, Plastic bags, Carton, Vacuum packing, Sprockets and chain set box, or as you likeMain marketsAsia, Mid east, South ... according to the world market, and OEM service is offered. chain sprocket with hardening teeth