hex head flange washer bolts material: carbon alloy steel size: 1/4"~1",M4~M24 surface: DAC,plain. zinc ... Professinal manufacturer and exporter of Fasteners. 1Name hex head flange washer bolts 2MaterialIron,carbon steel,brass,aluminum,stainless ... ,according to the formal quotation sheet12Head typesPan head,round head,round washer head,recessed head13Drive typesSlot, Phillips, Phillips tamper-resistant ...