S-91221A125 5/16"-18 x 3/4" ASME B18.3, UL 94 HB Plastic Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 17,000 psi ensures reliable, long-lasting fastening in demanding industrial environments.
• Lightweight and corrosion-resistant glass-filled nylon construction eliminates rust and reduces component weight without sacrificing durability.
• Wide operating temperature range from -40°F to 200°F maintains performance and dimensional stability in extreme conditions.
• Precise Class 2A thread fit with coarse UNC threading provides easy installation and secure engagement, minimizing the risk of cross-threading.
• Standard 1/4" hex drive allows for high-torque installation using common tools, ensuring efficient assembly and disassembly.
• Compliance with major standards including ASME B18.3, RoHS 3, and REACH guarantees product reliability and environmental safety for global supply chains.
• Fully threaded design offers consistent clamping force along the entire 3/4" length for versatile application use.

Professional Applications & Engineering Value

This glass-filled nylon socket head cap screw is engineered to solve critical challenges in industries where metal fasteners fail. Its non-conductive and corrosion-resistant properties make it ideal for electrical enclosures, food processing equipment, and marine applications, eliminating galvanic corrosion and contamination risks. The 5/16"-18 UNC coarse thread ensures rapid assembly in plastic and soft materials, while the 17,000 psi tensile strength provides the durability needed for structural components. With a -40°F to 200°F temperature range, it performs reliably in outdoor, automotive, and HVAC systems, offering a lightweight alternative to steel without compromising on ASME B18.3 mechanical specifications.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit tolerances per UNC standards, ensuring precise engagement. It is manufactured in compliance with ASME B18.3 for dimensional consistency and meets UL 94 HB flammability requirements. The product is RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, confirming the absence of hazardous substances for safe use in regulated industries.