1.materials:carbon steel,stainless steel 2.standard:DIN,ANSI,AS,BS 3.finish:zinc black hdg plain 4.size:M3-M52 & 1/4-2" JIASHAN JINDONG FASTEHERS CO.,LTD & JIASHAN JINLONG INTERNATIONAL TRADING CO.,LTD specially supply BOLTS,NUTS,WASHERS,SCREWS,THREAD RODS etc fasteners.if you are purchased BOLTS,NUTS,WASHERS,SCREWS,THREAD RODS etc,please do not hesitate to contact us.contact info as below: