S-90390A147 1/4"-20 x 5/8" Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction for extended service life in harsh industrial environments
• Enhanced torque transmission through T27 Torx drive design, minimizing cam-out and tool slippage during installation
• Self-tapping efficiency with thread cutting (Type F) design that creates precise mating threads in aluminum, brass, and cast iron without pre-tapping
• Optimal material engagement through UNC coarse threading and full threading along the 5/8" length for maximum holding power
• Flush mounting capability with standard flat head profile and 82° countersink angle for clean, professional finishes
• Simplified installation process with compatibility for standard No. 1 drill bits (0.228" diameter)
• Regulatory compliance assurance meeting RoHS 3 standards for environmentally responsible manufacturing

Professional Applications & Engineering Value

These 1/4-20 UNC zinc-plated steel tapping screws deliver exceptional engineering value in metal fabrication and assembly operations. The thread cutting technology eliminates the need for separate tapping operations, significantly reducing installation time and labor costs when working with aluminum, brass, cast iron, and sheet metal components. The T27 Torx drive system provides superior torque transfer compared to traditional drive types, preventing fastener damage and ensuring consistent clamping force in high-vibration applications. The 82° countersink angle and flat head design create seamless surface finishes while the coarse UNC threading maintains secure fastening in materials prone to thermal expansion and contraction cycles.

Specification Summary & Compliance

Manufactured to precise dimensional standards with UNC coarse thread spacing and Class 2A thread tolerances for reliable mating compatibility. The Type F thread cutting design follows established industrial standards for self-tapping fasteners in metallic materials. These zinc-plated steel screws feature a standard flat head profile with 0.477" head diameter and 0.153" head height. Fully compliant with RoHS 3 (2015/863/EU) regulations for restricted substance control, ensuring environmental responsibility in industrial applications.