S-90920A547 1/4"-20 x 1 1/2" ASME B18.6.3 Alloy Steel Torx Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, ensuring long-term reliability in harsh industrial environments
• Enhanced torque transmission and reduced cam-out thanks to the T27 Torx drive system, providing secure fastening and minimizing tool slippage
• High tensile strength of 60,000 psi combined with Rockwell B70 hardness for exceptional load-bearing capacity in demanding applications
• Precision Class 3A thread fit delivers consistent engagement and reliable clamping force in assembly operations
• 82° countersink angle with standard flat head profile enables flush mounting for clean, professional finishes
• Full threading along the 1½" length ensures maximum grip and uniform stress distribution across joined materials
• Compliance with ASME B18.6.3, RoHS 3, and REACH standards guarantees quality, safety, and environmental responsibility

Professional Applications & Engineering Value

These 1/4"-20 UNC flat head Torx screws are engineered to address critical challenges in industrial assembly and construction. The zinc-plated steel material provides excellent corrosion resistance, making them ideal for outdoor equipment, machinery enclosures, and structural frameworks exposed to moisture. The T27 drive system prevents stripping and allows higher torque application compared to traditional drives, reducing installation time and improving joint integrity. With coarse UNC threading and Class 3A fit, these screws offer rapid installation and vibration resistance in metal-to-metal and wood applications. The 82° countersink ensures a seamless finish in pre-drilled surfaces, while the fully threaded design maintains consistent holding power across the entire fastener length, eliminating weak points in heavy-duty assemblies.

Specification Summary & Compliance

Manufactured to inch system specifications with precise Class 3A thread fit per UNC standards, ensuring dimensional accuracy and interchangeability. These screws conform to ASME B18.6.3 mechanical and dimensional requirements, guaranteeing consistent performance in industrial applications. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted hazardous substances. The right-hand thread direction and coarse thread spacing provide reliable fastening in various materials, backed by verified 60,000 psi tensile strength and Rockwell B70 hardness ratings.