S-90275A107 4-40 x 5/16" ASME B18.6.3 Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, ensuring long-lasting performance in demanding industrial environments
• Exceptional tensile strength of 60,000 PSI provides reliable fastening under high-stress conditions, reducing the risk of fastener failure
• Precision Class 2A thread fit guarantees smooth assembly and consistent engagement, minimizing production delays
• Fully threaded design with coarse UNC spacing enables faster installation and superior holding power in various materials
• Standard 82° countersink angle ensures flush mounting for clean, professional finishes in visible applications
• Rockwell B70 hardness rating maintains thread integrity and prevents stripping during repeated installations
• Comprehensive compliance with ASME B18.6.3, RoHS 3, and REACH standards ensures regulatory acceptance for global industrial applications

Professional Applications & Engineering Value

These 4-40 UNC flat head slotted screws deliver critical engineering solutions where space constraints and surface finish requirements are paramount. The zinc-plated steel construction provides essential corrosion protection for machinery, electronic enclosures, and automotive assemblies exposed to moderate environmental conditions. The fully threaded right-hand coarse spacing design ensures maximum thread engagement in both metallic and non-metallic substrates, while the standard 82° countersink angle creates seamless flush installations in precision equipment and consumer products. Engineered to ASME B18.6.3 specifications, these slotted screws offer reliable performance in maintenance, repair, and OEM manufacturing operations where consistent fastening integrity is non-negotiable.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit tolerances ensuring compatibility with standard UNC nut and tapped hole applications. These screws conform to ASME B18.6.3 mechanical and dimensional requirements for flat head machine screws. Environmental compliance includes RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations for chemical safety, making them suitable for international industrial markets requiring verified material declarations.