S-91221A165 4-40 x 1 1/2" UL 94 HB Plastic Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional thermal performance with a wide operating range from -20° to 230°F, ensuring reliable fastening in varying environmental conditions
• Superior chemical resistance and durability provided by glass-filled nylon construction, ideal for harsh industrial environments
• Precise and secure threading with 4-40 UNC coarse threads and Class 2A fit for consistent engagement and reduced cross-threading risks
• Full-length threading design offers maximum grip and adjustability across the entire 1-1/2" length for versatile applications
• Easy installation and removal with standard hex drive (3/32") and socket head profile, compatible with common tools
• Regulatory compliance assurance meeting UL 94 HB flammability standards, RoHS 3, and REACH for global market acceptance
• Lightweight and corrosion-resistant off-white plastic construction eliminates galvanic corrosion and reduces overall assembly weight

Professional Applications & Engineering Value

This glass-filled nylon socket head cap screw delivers critical engineering advantages in demanding applications where metal fasteners fall short. Its 4-40 UNC coarse thread with Class 2A fit provides reliable performance in plastic assemblies, electrical enclosures, and machinery where vibration resistance and repeated adjustments are necessary. The fully threaded design ensures maximum holding power across the entire 1-1/2" length, while the hex drive 3/32" socket head prevents cam-out during torque application. Particularly valuable in chemical processing equipment, automotive components, and electronic housings, this fastener solves common problems of corrosion, electrical insulation, and weight reduction without sacrificing mechanical strength.

Specification Summary & Compliance

Manufactured to inch system specifications with precise UNC coarse threads maintaining Class 2A thread fit tolerances for consistent performance. The fully threaded rod type and standardized socket head profile ensure compatibility with industry tools and applications. Compliance certifications include UL 94 HB for flammability safety, RoHS 3 (2015/863/EU) for hazardous substance restriction, and REACH (EC 1907/2006) for chemical safety management, meeting international regulatory requirements for industrial components.