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GRK Fasteners 5/16 in. in. X 5-1/8 in. L Star Washer Head Self Tapping Structural Screws

Self-tapping W-Cut thread bites into dense lumber for solid structural connections, indoors or out, no pre-drilling required.
Grk Fasteners MPN 10231 In Stock & Ready to Ship
$339.99
Free shipping on orders over $149
Ships within 24 hours · most orders arrive in about 2 business days
Ships free on orders over $149 $14.99 flat shipping until your order reaches $149.

About Product Overview

Structural work calls for a fastener that can carry real load without splitting the wood or backing out under stress, and that's the job this GRK screw is built for. At 5/16 in. by 5-1/8 in. with a hex head and star drive, it's sized for heavy connections like ledger boards, beams, posts, and multi-ply framing where lag bolts have traditionally done the work. The W-Cut thread self-taps as it drives, cutting its own path through dense lumber so you get a clean, tight connection without pre-drilling in most applications. Climacoat finish stands up to moisture and outdoor exposure, so the same screw works whether you're building a deck, a pergola, or reinforcing framing inside a garage or shop. This box holds 300 screws, enough to stock a job site or keep on hand for repeat structural projects without running back to the store mid-build.

  • Callout size: 5/16 in., length: 5-1/8 in.
  • Hex head with star drive
  • W-Cut self-tapping thread, not self-drilling
  • Climacoat finish for indoor and outdoor use
  • Steel construction
  • 300 screws per box

The Details Specifications

Brand Grk Fasteners
Model / MPN 10231
UPC 772691102317
Weight 15 lbs
Safety Data Sheet (SDS) Manufacturer documentation · opens in new tab
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Who's actually selling it

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02

Whether the warranty survives

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03

Where the box came from

Gray-market stock, returns repackaged as new, and outright fakes move through marketplaces constantly. It all looks identical in the photo. It stops looking identical when it fails.

04

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