S-90086A607 4-40 x 5/16" ASME B18.6.3, SAE J933 Tapping Screws

Key Features & Benefits at a Glance

• Superior thread cutting performance in aluminum, brass, cast iron, and sheet metal for reliable, permanent fastening without pre-tapped holes.
• Enhanced corrosion resistance with zinc-plated steel construction, extending the screw's service life in various industrial environments.
• Efficient installation and reduced cam-out with the Phillips No. 1 drive and flat undercut head design, ensuring a flush finish and speeding up assembly.
• High-strength, coarse UNC threads provide excellent holding power and are less prone to stripping in softer materials.
• Optimized for 82° countersink applications with a fully threaded, blunt tip design for precise alignment and maximum material engagement.
• Guaranteed dimensional accuracy and interchangeability through compliance with the rigorous ASME B18.6.3 standard.
• Safe for use in regulated industries as these screws are RoHS 3 compliant, containing no restricted hazardous substances.

Professional Applications & Engineering Value

These 4-40 UNC tapping screws are engineered to solve common assembly challenges in metalworking and fabrication. The thread cutting Type F design and coarse thread spacing allow them to form their own threads in ductile materials like aluminum, brass, and cast iron, eliminating the time and cost associated with tapping operations. The zinc-plated steel material offers a durable barrier against rust, which is critical for components in electrical enclosures, machinery, and automotive assemblies exposed to varying conditions. The flat undercut head with an 82° countersink angle sits flush with the surface, preventing snagging and providing a clean, professional finish. This combination of features makes them an indispensable fastener for high-volume production lines where reliability, speed, and compliance with industry standards like ASME B18.6.3 are paramount.

Specification Summary & Compliance

This screw is specified with a #4-40 UNC thread and a length of 5/16 inch, featuring a coarse thread profile for robust performance. Manufacturing and dimensional tolerances conform to the ASME B18.6.3 standard, ensuring consistent quality and fit. The product is fully compliant with RoHS 3 (2015/863/EU) regulations, guaranteeing it is free from hazardous substances for safe use in global markets.