S-91772A556 1/4"-20 x 4 1/2" ASME B18.6.3 Stainless Steel Pan 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
• Exceptional holding power through partial threading design that provides optimal grip and vibration resistance
• High mechanical strength with 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Reliable drive engagement with No. 3 Phillips drive that prevents cam-out and ensures secure fastening
• Precision thread compatibility featuring UNC coarse 1/4"-20 threads with Class 2A fit for consistent mating with standard components
• Optimized head design with pan-style rounded profile for smooth surface finish and reduced snagging
• Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations for global industrial use

Professional Applications & Engineering Value

This partially threaded pan head Phillips screw delivers exceptional engineering value for industrial assembly applications where vibration resistance and corrosion protection are critical. The passivated 18-8 stainless steel construction provides superior protection against chemical exposure and environmental factors, making it ideal for machinery, equipment manufacturing, and outdoor installations. The UNC coarse thread design ensures quick assembly and reliable performance in high-vibration environments, while the partial threading concentrates clamping force precisely where needed. The No. 3 Phillips drive offers familiar, efficient installation with standard tools, reducing assembly time and improving workplace efficiency. This combination of features addresses common industrial challenges including material degradation, fastener loosening, and installation complexity.

Specification Summary & Compliance

This 1/4"-20 UNC coarse thread screw maintains precise Class 2A thread fit tolerances for consistent performance across industrial applications. Manufactured in compliance with ASME B18.6.3 specifications, the fastener ensures dimensional accuracy and mechanical reliability. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting the latest environmental regulations for hazardous substance restrictions. With a length of 4-1/2" and minimum thread length of 1-1/2", this partially threaded configuration provides optimal unthreaded shank for enhanced structural integrity.