GRK RSS Rugged Structural Screw has a patented design and made of specially hardened steel to provide customers with high 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 GRK RSS series screws that are 3-1/8-Inch and longer have six CEE threads which enlarge the screw hole for the non-threaded portion of the fastener, allowing the wood to settle easily and increases the screw’s drawing strength. The CEE thread also reduces the friction on the screw shank which can lower the driving torque and reduce splitting. The round head with built-in washer type head shield does not have any sharp edges like conventional lag screws. The added shoulder underneath the washer has the ability to center the RSS screw in pre-drilled hardware like hinges and connector plates. The RSS screws can be used as a lag screw alternative. Some sizes available is PHEINOX Stainless Steel.