GRK’s R4 self-countersinking screw has a new underhead with saw-blade like cutting teeth and six self contained cutting pockets. The screw head closes the hole off with precision, leaving no damaged fibers around the head. The R4 is available in 59 sizes from #4 by 3/8-inch to #12 by 12″. This multi-use screw can be used in wood, particle board, plastic, sheet metal, cement fiberboard, composite decking, wood decking and melamine. Some sizes are also available in PHEINOX stainless steel.
R4 Bit Table #4 uses T-10, #6 and #8 use T-15, #9, #10 and #12 all use T-25
Self-Tapping, countersinking head, W-cut thread design and Climatek coated
Wood, particle board, cement fiberboard, plastic and sheet metal
Multi-Purpose screw R4