GRK RT Composite™ screw is a specially designed fastener for attaching composite and cellular PVC materials. The RT Composite has a reverse threading under the head of the fastener that helps the screw head disappear beneath the surface and eliminate mushrooming when installing Composite materials. RT Composite Screws have a Climatek™ Coating for installation in both interior and exterior conditions where exposure to moisture is intermittent and is code-approved for use in treated lumber.
GRK RT Composite TRIM Head Screws have the smallest screw head available and work great for most fine carpentry applications. Most material splitting is prevented because of the TRIM Head screw's exceptionally small head and the W-Cut thread design. The RT screws include a reverse threading under the head of the fastener. GRK has found that the reverse thread helps the screw head disappear beneath the surface of the classic wood composite material, reducing or eliminating the dimple that sometimes appears. Some sizes are available in PHEINOX Stainless Steel.