Fastenmaster FMHLGM412-50 Headlok Structural Screw 50ct

Product Description

The FASTENMASTER FMHLGM412-50 is a Headlok heavy-duty structural screw designed for timber-to-timber and wood-to-OSB fastening applications. At 4.5 inches in length with a 0.172-inch diameter, this wafer head screw delivers shear values stronger than standard 3/8-inch lag screws without requiring a washer. The Spider Drive recess provides maximum bit engagement for controlled, high-torque installation. A sharp gimlet point starts fast without predrilling, and the aggressive thread profile generates high withdrawal strength. Each box contains 50 screws and includes a Spider Drive bit.

This screw is used in structural wood framing, ledger board attachment, post-to-beam connections, and deck substructure work. It is suited for residential and light commercial construction where engineered fastener performance is required. The wafer head profile sits flush or near-flush against the wood surface, eliminating the need for a separate washer and reducing installation steps. Carpenters, framers, and deck builders use this fastener where speed and structural integrity are both priorities.

Key Features

• Shear values exceed those of standard 3/8-inch lag screws
• Spider Drive recess delivers high bit engagement and reduced cam-out
• Sharp gimlet point enables fast starts without predrilling in wood and OSB
• Aggressive thread profile maximizes holding and withdrawal strength
• Wafer head with chamfer underneath increases pull-through resistance and eliminates washer requirement
• Includes one Spider Drive bit per box

Compatibility

Designed for structural fastening applications in wood framing and OSB assemblies typical of residential and light commercial construction.

Installation Notes

Installation is performed by carpenters and framers using a drill or impact driver with the included Spider Drive bit. Verify local building code requirements and any applicable IRC or IBC provisions for structural fastener spacing and edge distances before installation. Always use the correct bit to avoid damaging the drive recess and compromising torque transfer.

Technical Specifications

• Diameter: 0.172 inches
• Length: 4.5 inches
• Head Type: Wafer
• Drive Type: Spider Drive
• Point Type: Gimlet
• Package Quantity: 50 pieces
• Package Weight: 2.484 pounds
• UPC: 00608309410584

Standard Information

• Brand: FASTENMASTER
• Manufacturer Part Number: FMHLGM412-50