S-91770A554 1/4"-20 x 3" ASME B18.6.3 Stainless Steel Truss Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction for extended service life in harsh environments
• Enhanced load distribution through the wide rounded truss head design, reducing surface pressure and material damage
• High torque capability with Phillips No. 3 drive, ensuring secure installation and reduced cam-out risk
• Reliable thread engagement with Class 2A UNC coarse threads, providing consistent fastening in various materials
• Optimized strength-to-weight ratio featuring 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Controlled thread engagement through partial threading design, preventing over-tightening in precision assemblies
• Full regulatory compliance meeting ASME B18.6.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

Engineered for industrial applications requiring both corrosion resistance and structural integrity, this 1/4-20 UNC thread screw addresses common challenges in manufacturing, electronics, and outdoor equipment assembly. The passivated 18-8 stainless steel construction provides exceptional protection against oxidation and chemical exposure, while the rounded truss head design distributes clamping force over a wider area, preventing surface deformation in softer materials. The partially threaded configuration allows for precise control in applications where full thread engagement isn't required, making it ideal for securing panels, brackets, and machinery components. With its coarse thread spacing and Phillips drive system, installation efficiency is maximized in production environments where speed and reliability are critical.

Specification Summary & Compliance

This rounded head screw maintains precise Class 2A thread fit tolerances with 1/4"-20 UNC coarse threads and minimum thread length of 1-1/2". Manufactured according to ASME B18.6.3 specifications, the screw demonstrates full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial markets and restricted substance-sensitive applications.