Factory direct sales Of Cast Iron Balls Diameter: 20mm-150mm Manufacturing Process Of Cast Iron Balls: 1.Raw material 2.Melting 3.Pouring 4.Polishing 5.Heat treatment 6.Testing 7.Qualified products ( ISO CERTIFICATE) 8.Packing ( steel drum, flexible container bags) Porting of loading : Qingdao Port, China. Experience of Cast grinding ball production : 30 years