GRK Fasteners #10 x 3-1/8 In. Multi-Purpose Framing and Decking Screw

GRK’s R4 self-countersinking screw has a patented underhead with saw-blade like cutting teeth and six self-contained cutting pockets. Together they act similar to a circular saw-blade. transporting the drill dust away from the edge of the screw hole while cutting a perfectly clean hole into even the most brittle materials without cracking any surface treatment. This design enhances the R4 s versatility by allowing the fastener to countersink into even the hardest woods. The head of the screw closes the hole off with precision. leaving no damaged fibers around the head.