... C60600,C17200,etcAlumimum100,5052,6061,6063,etc(2),Ability for the surface finish: ElectroplateZinc plated(while,colour,dacroment), ... and polishing,etc,except mirror finish (3),Ability for the tolerance Roundess0.002mmCylindricity0.003mmRoughnessRa0.32Straightness0.01/200mm 3 ... avoid lots of risks.P.S:For us,the most competitive industry is machined hardware fastener ,especially the cutting/turning ...