R4™ Multi-Purpose Framing Screws
RK's R4™ self-countersinking screw has a patented 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 enhances the R4's versatility by allowing the fastener to countersink into even the hardest woods. The head of the screw closes the hole off with precision leaving no damaged fibers around the head.
R4™ screws 2" and longer have a four threaded CEE Thread. This enlarges the screw hole for the non-threaded portion of the fastener, allowing the wood to settle easily. It increases the screw's drawing strength and reduces the friction on the screw shank that lowers the driving torque.
RSS™ Rugged Structural Screws
GRK’s RSS™ Rugged Structural Screw is made of specially hardened steel to provide you with high tensile, torque and shear strength. The sharp threads and points bite instantly into the material (including hardwood), reducing the splitting effect due to smaller shanks.
RSS™ screws which are 3-1/8" and longer have a six threaded CEE thread that enlarges the screw hole for the non-threaded portion of the fastener, allowing the wood to settle easily and increasing the screw’s drawing strength. The CEE thread also reduces the friction on the screw shank which can result in lowering the driving torque and the likelihood of splitting the wood. This is why the RSS screw is an efficient lag screw alternative.
Our round head with built-in shield (washer type head) has no sharp edges like conventional lag screws. The added shoulder (nominal diameter) underneath the washer has the ability to center the RSS™ screw in pre-drilled hardware like hinges and connector plates.
Low-Profile Cabinet™ Screws
GRK's Cabinet™ screws are designed specifically for use in cabinet construction and installation. Cabinet™ screws are manufactured in a #8 gauge (4 mm) diameter for universal size convenience.
These screws are thin enough to prevent most material splitting, while providing sufficient strength to guarantee a secure installation. The washer head design presses flush against any material surface.
Builders have discovered that short Cabinet™ screws can sometimes be used in vinyl siding installation, which makes this fastener ideal for both interior and exterior applications.
Also can be used for light duty framing applications where a smaller diameter shank is necessary, yet a need exists for drawing power delivered by the washer head.
Fin/Trim™ Finishing Trin Head Screws
GRK's Trim™ Head screws are an excellent choice for most fine carpentry applications, as well as window extension jambs and more. Our Trim™ Head screws have the smallest screw head available; with screw lengths from 1-1/4" (30mm) to 5" (125mm).
Most material splitting is prevented because of the Trim™ Head screw's exceptionally small head and the W-Cut™ thread design.
Fin/Trim™ screws are also available in white powder coated finish to blend in with white wooden trim boards.
RT Composite™ Exterior Trim Screws
GRK has modified its innovative FIN/Trim™ Head screw to include reverse threading under the head of the fastener. This technology makes the RT Composite Trim Screw ideal for use in composite and cellular PVC trim.
Based on extensive tests, 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 when using the FIN/Trim™ screw.
The reverse thread feature is available in RT Composite™ screws from 2" to 3-1/8" in length in both regular Climatek™ coating and in white powder coated finish to blend in with popular white exterior composite and cellular PVC trim.
Top Star™ Adjustable Shim Screws
GRK's adjustable Top Star™ shim screw, is in fact a screw within a screw that allows you to install wooden doors or windows without the use of shims.
The quick and easy system reduces labr and allows for hassle free adjustment to ensure plumb installation.
Our product is suited to meet the needs of both professional contractors and weekend warriors making the job easier for one person.
Fine adjustments are as simple as the turn of a screw, even after years of use and settling.