S-90385A326 Length 1 1/4" ASME B18.6.3 Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction for extended service life in industrial environments
• Reliable thread forming capability through DST technology creates strong, permanent threads in plastic materials without chips
• Optimized plastic fastening performance with blunt tip design that prevents material splitting during installation
• Enhanced driving efficiency with Phillips No. 1 drive that provides secure tool engagement and reduces cam-out
• Precision thread engagement with 24 TPI right-hand threads ensuring tight, vibration-resistant connections
• Versatile pan head design offers excellent bearing surface and professional appearance for finished assemblies
• Industry-standard compliance meeting ASME B18.6.3 specifications for consistent quality and performance

Professional Applications & Engineering Value

These No. 4 zinc-plated steel tapping screws are specifically engineered for plastic fastening applications where traditional threaded fasteners fail. The DST thread forming technology creates strong, permanent mating threads in plastic substrates through material displacement rather than cutting, eliminating chip-related contamination issues common in plastic assembly. The blunt tip design prevents material splitting while the fully threaded shank maximizes pull-out strength. With 24 TPI precision threading and zinc-plated corrosion protection, these screws deliver reliable performance in automotive trim, electronic enclosures, consumer products, and industrial equipment where vibration resistance and long-term durability are critical. The combination of Phillips drive convenience and standardized dimensions ensures efficient installation in high-volume manufacturing environments.

Specification Summary & Compliance

These tapping screws feature precise Class 2A thread tolerances with a thread diameter of 0.112" and 24 threads per inch. The 1-1/4" length and No. 4 screw size provide optimal fastening depth for plastic assemblies. Manufactured to meet ASME B18.6.3 specifications for dimensional accuracy and performance requirements. The zinc-plated steel material offers basic corrosion protection suitable for indoor applications. Compatible with No. 44 drill bit (0.086" diameter) for proper hole preparation in plastic materials. The right-hand thread direction and fully threaded design ensure maximum engagement strength in plastic fastening applications.