S-91087A243 5/16"-18 x 2 1/4" Wood Screws

Key Features & Benefits at a Glance

• Superior torque transmission with T40 Torx drive to prevent cam-out and ensure reliable installation in demanding applications
• Enhanced corrosion resistance from black-phosphate steel coating, extending service life in wood and sheet metal environments
• Optimized thread engagement with UNC coarse threading and partial threading design for secure fastening and reduced material splitting
• Precision countersinking capability with 82° flat head profile for flush mounting and professional finish
• Reduced installation complexity through thread-forming design that eliminates need for pre-tapped holes
• Compliance assurance with RoHS 3 and REACH regulations for environmentally responsible manufacturing
• Versatile application range suitable for both wood and sheet metal projects with recommended H drill bit size (0.266")

Professional Applications & Engineering Value

These 5/16"-18 UNC coarse thread wood screws deliver exceptional performance in construction and fabrication applications where vibration resistance and pull-out strength are critical. The black-phosphate steel construction provides superior corrosion protection in humid environments, while the T40 Torx drive system ensures maximum torque transfer without stripping during high-tension assembly. The partially threaded design concentrates gripping power at the engagement point, preventing wood splitting in delicate materials and maintaining clamp force in sheet metal applications. With their 82° countersink angle and standardized dimensions, these screws provide consistent flush mounting in furniture, structural framing, and metal fabrication projects where precision and reliability are paramount.

Specification Summary & Compliance

Manufactured to precise dimensional standards with UNC coarse threads (5/16"-18) and Class 2A thread tolerances for consistent performance. The flat head profile features standard dimensions with 0.6" head diameter and 0.191" head height. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industrial applications. Designed for use with H drill bit (0.266" diameter) and compatible with standard installation practices for thread-forming screws in wood and sheet metal substrates.