S-90086A635 1/4"-20 x 7/8" ASME B18.6.3, SAE J933 Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments.
• Efficient self-tapping installation with thread cutting design, eliminating the need for pre-tapped holes and reducing assembly time.
• Wide material compatibility for reliable fastening in aluminum, brass, cast iron, and sheet metal applications.
• Secure flush mounting thanks to the standard flat head profile and 82° countersink angle for a clean, professional finish.
• Robust drive engagement with Phillips No. 3 drive, minimizing cam-out and ensuring consistent torque application.
• Durable coarse UNC threading providing strong holding power and resistance to vibration loosening in various substrates.
• Full compliance with ASME B18.6.3 and RoHS 3, guaranteeing consistent quality, safety, and environmental standards.

Professional Applications & Engineering Value

Engineered for precision and durability, these 1/4"-20 zinc-plated steel Phillips flat head tapping screws deliver exceptional value in industrial fastening. The thread cutting design allows for easy installation into tough materials like aluminum, brass, cast iron, and sheet metal, creating strong, permanent threads without pre-tapping. This eliminates common issues such as stripped threads and reduces labor costs. The zinc-plated finish provides a protective barrier against rust and corrosion, ensuring long-term reliability in humid or outdoor settings. With a standard 82° countersink angle and flat head, these screws sit flush with surfaces, preventing snagging and maintaining aesthetic integrity in assemblies. Ideal for machinery, metal fabrication, and automotive applications, they offer a dependable solution for high-stress environments where vibration resistance and material integrity are critical.

Specification Summary & Compliance

This tapping screw features a 1/4"-20 UNC coarse thread with full threading and standard Class 2A dimensional tolerances for consistent fit. Manufactured in accordance with ASME B18.6.3 specifications (referencing SAE J933), it ensures reliable performance and interchangeability. The product is fully RoHS 3 (2015/863/EU) compliant, adhering to strict environmental regulations for hazardous substance restrictions. Designed for use with a No. 1 drill bit (0.228" diameter), it supports precise installation in various metal substrates, reinforcing its role as a versatile, standards-based fastener for professional use.