S-99091A106 4-40 x 1/4" Plastic Hex Head Screws

Key Features & Benefits at a Glance

• Excellent corrosion resistance - Nylon plastic construction eliminates rust and chemical degradation, ensuring long-term reliability in harsh environments
• Superior electrical insulation properties - Non-conductive material prevents electrical shorts and makes these screws ideal for electronic applications
• Lightweight strength - High-strength nylon provides durable fastening while reducing overall assembly weight
• Wide temperature tolerance - Performs reliably in extreme conditions from -40° to 185°F without compromising integrity
• Precision threading - Class 2A UNC coarse threads ensure smooth installation and secure fit in various materials
• Easy installation and removal - External hex head design allows for standard wrenching tools and quick assembly
• Environmental compliance - RoHS 3 compliant construction meets international environmental standards for hazardous substances

Professional Applications & Engineering Value

These 4-40 UNC nylon plastic hex head screws deliver exceptional value in applications where metal fasteners fall short. The black nylon construction provides inherent corrosion resistance, eliminating galvanic corrosion concerns in mixed-material assemblies and making them perfect for marine, chemical processing, and outdoor equipment. Their electrical insulation properties solve critical safety challenges in electrical enclosures, circuit boards, and electronic devices where conductivity must be avoided. The coarse thread design with Class 2A fit ensures reliable performance in plastic and soft materials, preventing stripping while maintaining vibration resistance. With full threading along the entire 1/4" length, these screws distribute clamping force evenly, making them ideal for lightweight assemblies in automotive trim, consumer electronics, and aerospace components where weight reduction is crucial.

Specification Summary & Compliance

This 4-40 UNC hex head screw features precise Class 2A thread fit with 0.112" thread diameter and coarse thread spacing, manufactured to UNC standards for consistent performance. The fully threaded 1/4" length provides maximum engagement, while the external hex drive ensures compatibility with standard tools. These fasteners are RoHS 3 (2015/863/EU) compliant, meeting stringent environmental regulations for hazardous substance restrictions. The nylon plastic material maintains dimensional stability across the specified temperature range of -40° to 185°F, ensuring reliable performance in diverse operating conditions.