For over 20 years, GRK has produced contractor-grade fasteners for professional use, incorporating innovative design features to make screws that are faster and easier to drive, hold better in wood, plastic and composite materials, and reduce the risk of splitting.
These hardened steel screws have a rust-resistant Climatek coating that won't react with treated lumber. A pattern of cutting ridges on the underside of the head automatically countersink the screw. Self-tapping tips eliminate the need for pre-drilling, and sawtooth-like ridges on the threads near the tip reduce friction and driving effort. Secondary threads enlarge the upper portion of the hole slightly so the screw seats snugly with less torque.
The screws have Torx heads (and are supplied with a matching Torx bit) to reduce the potential for cam-out and slippage in the drive.