S-90399A201 Length 1 1/4" Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-phosphate steel construction for extended service life in demanding industrial environments
• Enhanced load distribution through the wide truss head design and integrated flat steel washer, preventing material damage and pull-through
• Efficient thread-forming installation with A/AB thread design creates strong, permanent threads in sheet metal without pre-tapping
• Maximum holding power achieved through full-length threading along the entire 1-1/4" length for secure, vibration-resistant fastening
• Optimized drilling compatibility with No. 29 drill bits (0.136" diameter) for precise installation in materials up to 0.025" thickness
• Reliable drive engagement with Phillips No. 2 drive system ensuring consistent torque application and reduced cam-out risk
• Versatile sheet metal applications with 0.164" thread diameter and 15 TPI providing secure fastening in various industrial assembly scenarios

Professional Applications & Engineering Value

These No. 8 Phillips Truss Head tapping screws deliver exceptional engineering value for sheet metal fabrication and industrial assembly applications. The thread-forming A/AB design eliminates the need for separate tapping operations, creating strong, permanent threads that resist vibration loosening and material fatigue. The combination of black-phosphate steel construction and integrated flat steel washer provides superior corrosion protection while distributing clamping force across a wider surface area, preventing material deformation in thin-gauge metals. The fully threaded design ensures maximum thread engagement throughout the entire fastener length, delivering reliable performance in HVAC systems, electrical enclosures, automotive components, and machinery assemblies where vibration resistance and long-term reliability are critical.

Specification Summary & Compliance

These thread-forming tapping screws feature precise 0.164" thread diameter with 15 threads per inch and right-hand threading conforming to standard industrial specifications. The fasteners maintain consistent dimensional accuracy with Class 2A thread tolerances for reliable installation performance. Manufacturing complies with industry standards for A/AB thread-forming screw designs, ensuring proper material displacement and thread formation in sheet metal applications. The black-phosphate surface treatment provides corrosion resistance while maintaining compatibility with standard industrial practices and environmental regulations.