... Cutter’s quality performance is good.(3)Long work life.(4)Stocks adequate, time delivery.(5)Rich experience in drill ... Sizes5/16" (8mm), 1/2" (13mm), 5/8" (16mm), 3/4" (19mm), etc.MaterialAlloy steel, carbideFormation or layerSoft, medium soft, hard ... layer and tungsten carbide, reduces reidual stress of PDC diamond compact cutter, and increase impact resistance.Themal stability-the resist temperature ...