Deck Screw, #10 x 2-1/2 in, Steel, Flat Head, Torx Drive
GRKs R4 Selfcountersinking screw has a patented underhead with sawblade like cutting teeth and six selfcontained cutting pockets Together they act similar to a circular sawblade, 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 R4s 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 R4 screws 318 and longer have a four threaded CEE thread This enlarges the screw hole for the nonthreaded portion of the fastener, allowing the wood to settle easily It increases the screws drawing strength and reduces the friction on the screw shank that lowers the driving torque.