Hex Head Double Grip Class 4 Self Drilling Screw 39mm

Hex washer head galvanised, 12g, with 14 threads per inch, 39mm double grip self drilling screw with neoprene washer. Primarily used for fastening steel roofing material to a steel structure. Class 4 finish to AS3566. The length is measured from the underside of the head. Use with a 5/16ths nut setter driver bit such as these.