... Black steel hex screw Process:Mahined and turned Surface:BO SGS audited More than 20 years experience in special fastener 1,Name:Black steel ... hex screw;black hex screw;steel hex screw 2,For the similar hex ... 8,5.6,6.8,8.8,9.8,10.9,12.9,etcCarbon steelGr.B,Gr.C,Gr ... hardware fastener ,especially the cutting/turning parts. Black steel hex screw