The main component of the working part (head) is green silicon carbide (GC) which is made of petroleum coke and high-quality silica and smelted at high temperature. The hardness is between corundum and diamond, and the mechanical strength is higher than corundum. 

Type：9#、10 #、11 #、20 #、31 #、33 #、35 #、42 #、48 #、58 #

Specs：10 pieces/box