S-91221A123 1/4"-20 x 3" ASME B18.3, UL 94 HB Plastic Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional durability and lightweight performance with glass-filled nylon construction, ideal for reducing overall assembly weight without sacrificing reliability.
• High tensile strength of 17,000 psi ensures secure fastening in demanding applications, minimizing the risk of failure under load.
• Wide temperature resistance from -40° to 200°F allows consistent performance in varied environmental conditions, from freezing cold to moderate heat.
• Precise UNC coarse threads with Class 2A fit provide easy installation and reliable engagement, reducing cross-threading and assembly time.
• Hex socket drive (3/16") offers secure tool engagement and high torque application, enabling efficient installation in confined spaces.
• Compliance with ASME B18.3, RoHS 3, and REACH standards ensures product quality, safety, and environmental responsibility for industrial use.
• Fully threaded design allows for adjustable positioning and uniform clamping force along the entire 3" length.

Professional Applications & Engineering Value

This glass-filled nylon socket head cap screw is engineered to address common challenges in industrial settings, such as corrosion sensitivity, electrical insulation needs, and weight reduction. The glass-filled nylon material provides excellent mechanical strength and dimensional stability, resisting deformation under stress while offering inherent resistance to many chemicals and moisture. With UNC coarse threads and a Class 2A thread fit, it ensures quick, reliable fastening in assemblies where vibration or thermal cycling may occur. The hex drive style and standard socket head profile facilitate easy installation with common tools, making it suitable for machinery, electronics enclosures, and automotive components where temperature resistance and regulatory compliance are critical. Its off-white color and non-magnetic properties further enhance its use in sensitive or aesthetic-driven applications.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 2A fit for precise dimensional accuracy and reliable engagement. It is manufactured in accordance with ASME B18.3 specifications, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of hazardous substances and safe for various industrial and commercial uses. Additionally, it meets UL 94 HB flammability standards, supporting its application in environments where material safety is prioritized.