GRK's R4 self-countersinking screw has a patented under head 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 an ideally 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 3-1/8 in 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.

Product Details

• Applicable Materials: Cement Fiber Board Composite Melamine Particle Board Plastic Sheet Metal Wood
• Color: Yellow
• Drive Type: Star
• Finish: Climatek
• Head Type: Bugle
• Length: 3-1/8
• Material: Steel
• Package Quantity: 630 PK
• Point Type: Self-Drilling Self-Tapping
• Thread Size: 10
• Type: Multi-Purpose

Features

• Fast bite tip eliminates pre-drilling and provides a fast start for one step installation
• W-Cut™ low installation torque allows for fast driving and ease of install
• Precision fit between R4™ multi-purpose screws and GRK bits reduces wobble and improves productivity