GRK Fasteners-10221 772691102218 RSS Bulk 5/16-Inch by 3-1/8-Inch Screw, 500 per Product Description GRK's 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. From the Manufacturer GRK's 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. Features Built-in washer head Climatek coated and hardened steel ICC report ESR-2442 Uses GRK bit T-30 Self-tapping USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.