S-90390A556 1/4"-20 x 4" Tapping Screws

Key Features & Benefits at a Glance

• Superior thread cutting performance in aluminum, brass, cast iron, and sheet metal without pre-tapped holes, reducing installation time and labor costs.
• High-torque T30 Torx drive minimizes cam-out risk, allowing for greater tightening force and improved assembly reliability.
• Durable black-phosphate steel construction provides excellent corrosion resistance, extending service life in demanding industrial environments.
• 82° flat head with standard profile ensures a flush, professional finish when used with appropriate countersunk holes.
• Coarse 1/4"-20 UNC threads offer rapid installation and strong holding power in a wide range of base materials.
• Fully threaded 4" length provides maximum grip range and versatility for various material thicknesses.
• Type F thread cutting design creates precise mating threads for secure, vibration-resistant fastening.

Professional Applications & Engineering Value

These 1/4-20 UNC thread cutting screws solve critical fastening challenges in metalworking and construction applications. The black-phosphate steel material combined with the Type F tapping screw design enables direct installation into aluminum, brass, cast iron, and sheet metal without separate tapping operations. The T30 Torx drive system delivers maximum torque transfer while preventing tool slippage that can damage screw heads and compromise joint integrity. The 82° countersink angle and flat head profile create seamless surfaces ideal for applications where protrusions are unacceptable. These fully threaded screws maintain consistent holding strength throughout their 4" length, making them perfect for heavy-duty industrial fastening in structural frameworks, machinery assembly, and metal fabrication projects where vibration resistance and long-term reliability are paramount.

Specification Summary & Compliance

Manufactured to precise dimensional standards with UNC coarse threads and Class 2A thread fit for reliable performance. These Type F thread cutting screws feature a blunt tip and right-hand thread direction with 0.228" drill bit size recommendation for proper hole preparation. Complies with industry standards for tapping screws and contains RoHS and REACH compliant materials suitable for various industrial applications.