Centre bolt: 1, High quality and good price. 2, High technic of heat treatment. 3, Excellent team worker, service for you. center bolt 1. Material: 40Cr2.Quality Grade: 8.8,10.9,12.9-grade3.Surface: Galvanized(Yellow/Silver), Phosphated, Dacromet4.Color : Optional5.Finishing: Bake Paint, Black Oxide, Zinc Plated, Phosphate, Electrophoresis, Dacromet, with high temperature treatment.6.We can make ...