The polyurethane ball is componded by advanced technology.A steel ball,casted a3mm polyurethane layer that has high wear-resistance and no contamination.It¡¯s widely used for mixing and grinding electronic material,lithium cobaltate material and other material. We adopt complex technology in order to pledge quality.It is heavier than alumia ball,Shao¡¯s hardness is 90.It¡¯s material is imported polyurethane. Main model: §¶15¡¢§¶20¡¢§¶25¡¢§¶30.