GRK's R4 self-countering screw has a new 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. Applications include wood, particle board, plastic, sheet metal, cement fiberboard, composite decking, wood decking and melamine.
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