... screw, countersunk head self drilling screw, wafer/frame head self drilling screw, slotted countersunk head, cross recessed countersunk head…..Material: carbon ... steel C1022Size:4.0/4.2/4.5/4.8/5.0*19---60mm,Feature:pan head ... , drill-shaped point.Head type: hex/ wafer/frame/countersunk headFinished: galvanized ...