(1) Material:Carbon steel ball  AISI1008~AISI1018,AISI1045,AISI1065~AISI1086     Size: 1.0mm----80mm     Grade: G5----G1000Carbon steel ball is very common for  a ball with low price,high hardness characteristics. Commonly used in bicycles,bearings,caster,slide,toys,pulleys,valves,hardware......(2) Material: Stainless steel ball   AISI302/304/304L/316/316L/420/430/440C/440 etc.     Size:0.17mm-----12.7mm     Grade: G5----G1000Stainless steel ball commonly used in more sophisticated products,precision bearings,meadical dental drill bearing,caster,bearing,toys,valves,decorations.....strong and durable.(3)Material: Chrome steel ball  E50100,E51100,E52100 etc.    Size:0.8mm-----80mm    Grade: G10----G1000Chrome steel ball made of imported grinding hard alloy materials,advanced technology,high corrosion resistance,often used in bearings.