S-90385A321 Length 3/16" ASME B18.6.3 Tapping Screws

Key Features & Benefits at a Glance

• Superior material engagement with thread forming design that creates strong, permanent threads in plastic without chipping or cracking
• Enhanced corrosion resistance through zinc-plated steel construction for extended service life in various environments
• Optimized installation efficiency with Phillips drive system providing secure tool engagement and reduced cam-out risk
• Maximum holding power achieved through fully threaded design that distributes load evenly across the entire fastener length
• Precision material compatibility with blunt tip design that prevents material damage during installation in plastic components
• Reliable dimensional consistency meeting ASME B18.6.3 specifications for guaranteed interchangeability and fit
• Simplified assembly process with pre-determined No. 44 drill bit size for accurate hole preparation and optimal thread formation

Professional Applications & Engineering Value

This No. 4-24 thread forming tapping screw delivers exceptional value in plastic assembly applications where material integrity is paramount. The zinc-plated steel construction provides necessary corrosion protection while maintaining the strength required for durable fastening. The thread forming design (DST type) eliminates the need for tapped holes by displacing plastic material to create strong, load-bearing threads without generating chips that could interfere with electronic components or moving parts. The fully threaded configuration ensures maximum engagement in thin plastic sections, while the blunt tip prevents material splitting during installation. Particularly valuable in plastic assembly applications across automotive trim, electronics enclosures, and consumer products, this screw's Phillips drive and standardized dimensions enable efficient high-volume installation while maintaining consistent clamping force.

Specification Summary & Compliance

This tapping screw features precise dimensional specifications including No. 4 screw size, 0.112" thread diameter, 24 TPI thread pitch, and 3/16" length with Class 2A thread tolerances. The fastener complies with ASME B18.6.3 standards for dimensional consistency and performance requirements. Manufactured from zinc-plated steel with a pan head profile and Phillips No. 1 drive, it's designed for use with No. 44 drill bit (0.086" diameter) in plastic materials. The right-hand threaded, fully threaded configuration with thread forming tapping method ensures reliable performance in industrial assembly applications.