Diamond Grinding Blocks: 1.Metal Block:30#,40#,50#,60#,80#,100#,120#,150#,200#,300# 2.Resin Block:400#,600#,800#,1500#,3000# Diamond Grinding Blocks: Be used ... for automatic continuous polishing machine or single head grinding machine.High efficiency and good polishing effect.Metal Block:30 ...