S-99477A121 1/4"-20 x 1/2" ASME B18.3, UL 94 HB Plastic Socket Head Screws

Key Features & Benefits at a Glance

• Superior chemical resistance from polypropylene construction for reliable performance in corrosive industrial environments
• Excellent thermal stability with operating range from -20° to 180°F for consistent performance across varying temperature conditions
• High tensile strength of 4500 psi ensures dependable fastening in demanding mechanical applications
• Precision Class 2A thread fit provides smooth installation and secure fastening with consistent engagement
• Standard hex drive compatibility with 3/16" drive size for easy installation using common industrial tools
• Comprehensive regulatory compliance including RoHS 3 and REACH for global industrial applications
• Coarse UNC threading offers faster assembly and reduced cross-threading risks in production environments

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these polypropylene socket head cap screws deliver exceptional value in environments where metal fasteners would corrode or contaminate processes. The off-white polypropylene material provides outstanding resistance to chemicals, solvents, and moisture, making them ideal for chemical processing equipment, food machinery, and laboratory installations. The 1/4"-20 UNC coarse thread design ensures rapid assembly while maintaining secure fastening, while the standard hex drive accommodates common industrial tools for efficient maintenance and installation. These plastic socket head screws eliminate galvanic corrosion concerns when used with compatible materials and maintain integrity across a wide temperature range from -20° to 180°F, providing reliable performance in fluctuating thermal conditions common in industrial settings.

Specification Summary & Compliance

Manufactured to precision Class 2A thread fit standards with 1/4"-20 UNC coarse threading and right-hand thread direction. These socket head cap screws fully comply with ASME B18.3 specifications for dimensional accuracy and performance. The product meets RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and safety in industrial applications. With 1/2" length and 3/8" head diameter, these fasteners maintain consistent dimensional stability across production batches for reliable interchangeability.