GRK 772691102256 RSS Bulk 5/16-Inch by 4-Inch Screw
GRKs RSS screw is made of specially hardened steel to provide you with tensile, torque and shear strength. The sharp threads and points bite instantly into material (including hardwood), reducing the splitting effect due to smaller shanks. The round head with built-in shield (washer type head) has no sharp edges like conventional lag screws. The GRK RSS screw is a great lag screw alternative.
GRK 772691102256 RSS Bulk 5/16-Inch by 4-Inch Screw
GRK Fasteners 772691001054 R4 Bulk Number-9 by 3-1/8-Inch Screw
GRKs R4 self countersinking 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. This design also further enhances the R4s versatility by allowing the fastener to be installed without countersinking into even the hardest woods. The screw head closes the hole off with precision, leaving no damaged fibers around the head.
GRKs R4 self countersinking 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. This design also further enhances the R4s versatility by allowing the fastener to be installed without countersinking into even the hardest woods. The screw head closes the hole off with precision, leaving no damaged fibers around the head.