S-91221A211 4-40 x 1/8" UL 94 HB Plastic Socket Head Screws

Key Features & Benefits at a Glance

• Enhanced durability and strength from glass-filled nylon construction, providing superior performance compared to standard plastic fasteners
• Corrosion-resistant properties eliminate rust concerns in humid or chemical environments, ensuring long-term reliability
• Wide temperature tolerance from -20° to 230° F maintains structural integrity across diverse operating conditions
• Precise Class 2A thread fit ensures secure fastening with consistent engagement and reduced cross-threading risks
• Standard hex drive design enables quick installation with common tools while preventing cam-out during torque application
• Comprehensive regulatory compliance including UL 94 HB flammability rating and RoHS/REACH environmental standards
• Lightweight electrical insulation makes these screws ideal for electronic assemblies where conductivity must be avoided

Professional Applications & Engineering Value

These glass-filled nylon socket head cap screws deliver exceptional engineering value where metal fasteners would compromise performance. The 4-40 UNC coarse thread configuration provides excellent holding power in plastic components and soft materials, while the hex drive design ensures reliable torque transmission without stripping. The glass-reinforced nylon material solves critical challenges in electrical applications by providing natural insulation properties and eliminating galvanic corrosion concerns. These temperature-resistant screws maintain dimensional stability across industrial environments, from electronics enclosures to medical devices, where UL 94 HB compliance ensures safety in potential fire scenarios. The off-white color blends aesthetically with modern equipment while the Class 2A thread fit guarantees consistent assembly performance.

Specification Summary & Compliance

These inch-system fasteners feature 4-40 UNC coarse threads with Class 2A thread fit for precision engagement. Manufacturing complies with UL 94 HB flammability standards for material safety, along with full RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) compliance regarding hazardous substances. The socket head profile follows industry-standard dimensions with 3/32" hex drive compatibility. Temperature performance is certified from -20° to 230° F without degradation of mechanical properties.