GG25 V belt pulley ceramic pulley pulley,3",3.5",4",4.5",6",6. ... ",20",22",etc.we can sup GG25 V belt pulley ceramic pulley pulley,3",3.5",4",4.5",6",6 ... Process:Design and build the mould → Molding the Sand→ Melt and Injection → Sand Blasting and Polishing → Surface Treatment → Clean the Parts → Machining → General ...