S-91221A221 4-40 x 1" UL 94 HB Plastic Socket Head Screws

Key Features & Benefits at a Glance

• Superior chemical resistance from glass-filled nylon construction, ideal for harsh industrial environments
• Excellent electrical insulation properties for safe use in electrical assemblies and sensitive equipment
• Wide temperature tolerance (-20° to 230°F) ensures reliable performance across diverse operating conditions
• Precise Class 2A thread fit with UNC coarse threads for easy installation and secure fastening
• Durable hex drive design (3/32") provides superior torque transmission and prevents stripping
• Regulatory compliance with UL 94 HB flammability rating, RoHS 3, and REACH for global market acceptance
• Lightweight corrosion-resistant alternative to metal screws without sacrificing mechanical strength

Professional Applications & Engineering Value

These glass-filled nylon socket head cap screws deliver exceptional value in applications where metal fasteners pose conductivity or corrosion risks. The 4-40 UNC coarse threads with Class 2A fit ensure rapid assembly in plastic components and soft materials while maintaining vibration resistance. The off-white color and UL 94 HB compliance make them ideal for consumer electronics, medical devices, and automotive interiors where flammability standards and aesthetic consistency matter. Their temperature resistance and chemical inertness solve corrosion issues in chemical processing equipment, while the electrical insulation properties prevent short circuits in electrical enclosures and PCB mounting applications.

Specification Summary & Compliance

These screws feature 4-40 UNC coarse threads with Class 2A thread fit precision and standard socket head profile. Manufacturing complies with UL 94 HB flammability standards and environmental regulations including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance. The 1" length and 0.183" head diameter maintain dimensional consistency for reliable integration into engineered assemblies.