S-91771A185 3-56 x 1/4" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction for long-lasting performance in demanding environments
• Maximum holding power through fully threaded design and 80,000 psi tensile strength for reliable fastening in critical applications
• Precise flush installation with standard 82° countersink angle and flat head profile for smooth, professional finishes
• Consistent thread engagement with Class 2A thread fit and UNF fine threading ensuring secure, vibration-resistant connections
• Easy installation and removal using Phillips No. 1 drive system for efficient assembly and maintenance operations
• Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations including RoHS and REACH
• Versatile right-hand threading compatible with standard installation tools and procedures across various industries

Professional Applications & Engineering Value

These 3-56 UNF flat head screws deliver exceptional engineering value through their passivated 18-8 stainless steel composition, providing superior corrosion resistance that prevents degradation in humid or chemically aggressive environments. The fine thread configuration and Class 2A thread fit ensure precise engagement with mating components, eliminating play and maintaining structural integrity under vibration and dynamic loads. The 82° countersink angle facilitates perfect flush mounting in precision assemblies, while the Phillips drive system enables efficient installation in confined spaces. Ideal for electronic enclosures, precision instruments, and aerospace components, these screws solve critical fastening challenges where reliability, corrosion resistance, and dimensional accuracy are paramount.

Specification Summary & Compliance

Manufactured to exacting ASME B18.6.3 specifications, these screws feature Class 2A thread fit tolerances for consistent performance. The 3-56 UNF fine thread configuration ensures precise engagement, while the 1/4" length and fully threaded design provide maximum holding capability. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmental responsibility and workplace safety standards are met for global industrial applications.