14X2 Slotted Indented Hex Washer 7/16 A/F Self Drilling Screw Full Thread Zinc (Pack Qty 1,000) BC-143207KSW

May be used for drilling through wood over 1/2” thick and the metal surface behind it. The wings drill out a clearance hole in wood or other soft materials, then snap off when in contact with the metal surface to be drilled