S-91221A148 8-32 x 1/2" ASME B18.3, UL 94 HB Plastic Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional Strength-to-Weight Ratio: Glass-filled nylon construction delivers a high tensile strength of 17,000 psi, providing reliable performance in demanding applications without the weight of metal alternatives.
• Superior Corrosion & Chemical Resistance: Inherently corrosion-proof plastic material ensures long-term reliability in harsh environments, eliminating the risk of rust and galvanic corrosion.
li>Wide Operational Temperature Range: Maintains integrity and performance in temperatures from -40°F to 200°F, suitable for both extreme cold and moderate heat applications.
• Precision Thread Fit for Secure Fastening: Class 2A UNC coarse threads ensure easy, rapid assembly and a secure, reliable hold that resists loosening under vibration.
• Optimized for High-Torque Installation: The standard 9/64" hex socket drive allows for high torque application with standard tools, preventing cam-out and head stripping.
• Broad Industry Compliance: Manufactured to ASME B18.3 specifications and compliant with RoHS 3 and REACH, ensuring material safety and global regulatory acceptance.
• Electrical & Thermal Insulation: Non-conductive and thermally insulating properties make it ideal for electrical assemblies and applications where metal fasteners pose a short-circuit risk.

Professional Applications & Engineering Value

This 8-32 UNC thread socket head cap screw is engineered to solve critical challenges in industrial design and assembly. The glass-filled nylon plastic material provides a unique combination of high tensile strength and lightweight properties, making it an ideal replacement for metal fasteners in corrosive or electrically sensitive environments. Its fully threaded design and Class 2A thread fit ensure maximum grip and holding power across the entire 1/2" length, which is crucial for components subject to vibration. The coarse thread profile facilitates faster installation and reduces the risk of cross-threading. Commonly specified in electronics enclosures, automotive components, food processing equipment, and outdoor machinery, these black plastic screws deliver long-term reliability without the maintenance concerns of corrosion-prone metals.

Specification Summary & Compliance

This fastener adheres to precise dimensional standards, featuring an 8-32 UNC thread with a Class 2A fit for consistent and reliable assembly. It is manufactured in compliance with the ASME B18.3 standard for socket head cap screws. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free of hazardous substances and safe for use in a wide range of industries and global markets.