Description: Size : M5.5~M6.3 / #12~#14 / 1/4 Length : 50~100mm / 2”~3 15/16” Material : Carbon Steel / stainless Steel Drilling Point Type : #2/#3/#4/#5 / Reduced point Washer Type : BAZ Washer Surface Treatment : Zinc plated, Yellow Zinc plated, Black zinc, Zinc Nickel, Mechnical Galvanized, Ruspert, Slat Spray Test according to customer requirement. Standard : According to customers' drawing Package : Bulk packing, Box packing, Bag packing, Blister Special Wing Tek Screw Usage : This kind of screw has special tek it closes to head of screw. Due to this screw used in wave board when fasten in object will interspace that let stretch space during wind blowing. It makes wave board will not distortion and deform ; BAZ washer has big bowl washer obviously prevents water into object . This screw used in fiberglass to wood for roofing.