Black steel threaded rod Dia:Min 2 mm Surface :Zn SGS ... ,Name: Black steel threaded rod ;Steel threaded rod;Black threaded rod2,For the similar threaded rod ,what can we do ... Ability for the material of this kind of threaded rod: Grade3.6,4.6,4.8,5.6,6 ... polishing,etc,except mirror finish(3),Ability for the tolerance Roundess0.002mmCylindricity0.003mmRoughnessRa0.32Straightness0.01/200mm3,How about the ...