5 16 in. x 5 1 8 in. Star Drive Low Head Washer Rugged Structural Wood Screw (40 Piece per Pack) "Ceiling Fan" The 4 fold screen door is The 4 fold screen door is the most convenient alternative to regular shower curtains specifically designed and sized to fit on walk in bathtubs This semi frameless 4 fold shower screen gives an airy open feeling with the option to push the screen aside quickly and easily Patented adjustable through bolt allows easy installation retrofits existing doors Interior Returnable 180 Day Finish Climatek corrosion resistant coating Drive Style Star Fastener Plating Yellow Zinc Fastener Type Wood Screw Measurement Standard SAE Finish Family Zinc Fastener Connector Material Steel Head Style Low Profile Washer Size 5 16 in Screw Length 5 1 8 in Thread Pitch 0 Manufacturer Warranty No Its washer type head has no sharp edges like conventional lag screws and the added shoulder underneath the washer has the ability to center the RSS screw in predrilled hardware