5/16 In. In. X 3-1/8 In. L Star Hex Head W-cut Structural Screws

GRK Fasteners RSS structural screws are engineered for demanding construction and outdoor projects where strength and reliability matter most. Made from specially hardened steel, these fasteners deliver exceptional tensile, torque, and shear strength for carrying beams, ledger boards, stair rails, deck posts, and other load-bearing applications. The RSS screw is an efficient alternative to traditional lag screws, combining superior performance with easier installation and reduced splitting risk.

The round washer head design provides a professional finish with no sharp edges, and the built-in shoulder centers the screw in pre-drilled hardware like hinges and connector plates. Sharp threads and points bite instantly into materials including hardwood, while the CEE thread design on screws 3-1/8 inches and longer enlarge the screw hole for the non-threaded portion, allowing wood to settle easily and increasing drawing strength. This reduces friction on the screw shank, lowering driving torque and the likelihood of wood splitting.

Features and Benefits

• Self-Drilling Design: Sharp threads and points eliminate the need for pre-drilling in most applications, saving time on the job site.
• CEE Thread Technology: Reduces friction on the screw shank, lowering driving torque and the likelihood of wood splitting while increasing drawing strength.
• Hardened Steel Construction: Provides high tensile, torque, and shear strength for structural and heavy-duty applications.
• Washer Head with No Sharp Edges: The round head with built-in washer creates zero-gap joints and a clean professional appearance compared to conventional lag screws.
• Star Drive Head: Designed for reliable fastening in construction and structural applications.
• Efficient Lag Screw Alternative: Combines the strength of lag screws with easier installation and better wood compatibility.

Specifications

• Brand: GRK Fasteners
• Model: 14221
• Thread Size: 5/16 in.
• Length: 3-1/8 in.
• Head Type: Washer head with star drive
• Material: Steel, hardened
• Pack Size: 25 screws
• Standards: Meets ICC ESR-2442 for safety and performance