GG25 V belt pulley ceramic pulley pulley,3",3.5",4",4.5",6",6. ... 16",18",20",22",etc.we can sup GG25 V belt pulley ceramic pulley pulley,3",3.5",4",4.5",6",6. ... 18",20",22",etc.we can supply many kinds of pulley. 1). Material: GG25 iron alloy or according to ... and Injection → Sand Blasting and Polishing → Surface Treatment → Clean the Parts → Machining → General Checking → Packing and Anti-rust Protect → ...