Square Head Bolt be used for bulid or construct Square Head Bolt2)standard:din Square Head Bolt,ASTM Square Head Bolt,BSW Square Head Bolt,UNI Square Head Bolt3)size:m6-m50,length:15mm-300mm4)class: 4.8,8.8,10.85)surface:plain, black,H.D.G,ZINC,DACROMET6)material: stainless steel ,alloy steel,carbon steel7)package:bulk packing,small boxes,pocket. Square Head Bolt