S-91770A867 1/4"-20 x 3 1/4" 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 long-lasting performance in harsh environments
• Enhanced load distribution from the wide rounded truss head design that minimizes surface damage and prevents pull-through
• High-strength reliability with 70,000 PSI tensile strength and Rockwell B70 hardness for demanding applications
• Quick installation efficiency through UNC coarse threading and Phillips No. 3 drive combination
• Precise thread engagement with Class 2A thread fit ensuring consistent fastening performance
• Optimized material usage with partial threading that reduces weight while maintaining structural integrity
• Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations

Professional Applications & Engineering Value

This rounded truss head screw delivers exceptional engineering value across industrial applications where vibration resistance, corrosion protection, and reliable clamping force are critical. The passivated 18-8 stainless steel construction provides superior protection against corrosive elements in manufacturing, marine, and outdoor equipment applications. The wide truss head profile distributes clamping force over a larger surface area, preventing damage to softer materials while providing excellent resistance to loosening under vibration. The combination of UNC coarse threading and Phillips No. 3 drive enables rapid installation in production environments, while the partial threading design optimizes strength-to-weight ratio for applications requiring precise unthreaded shank sections. This fastener addresses common industrial challenges including material compatibility, installation efficiency, and long-term durability in demanding conditions.

Specification Summary & Compliance

This precision-engineered fastener maintains Class 2A thread fit tolerances with 1/4"-20 UNC coarse threading and right-hand thread direction. Manufacturing conforms to ASME B18.6.3 specifications, ensuring dimensional accuracy and performance reliability. The screw is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for global industrial applications requiring strict regulatory adherence.