S-90275A597 5/16"-18 x 3 1/2" ASME B18.6.3 Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance through zinc plating, extending service life in demanding industrial environments
• High tensile strength of 60,000 psi ensures reliable performance under heavy loads and vibration
• Rockwell B70 hardness provides excellent durability and resistance to wear during installation and use
• Class 2A thread fit with UNC coarse threading enables quick assembly and secure fastening in various materials
• 82° countersink angle with standard flat head profile creates flush surface finishes for streamlined applications
• Full threading along the 3-1/2" length offers maximum grip and adjustment flexibility
• Compliance with major industry standards including ASME B18.6.3 ensures consistent quality and performance

Professional Applications & Engineering Value

This zinc-plated steel flat head screw addresses critical engineering challenges in industrial fastening applications where corrosion resistance and structural integrity are paramount. The combination of 60,000 psi tensile strength and Rockwell B70 hardness provides exceptional load-bearing capacity while resisting deformation during installation. The UNC coarse thread pattern with Class 2A fit ensures reliable engagement in wood, metal, and composite materials, reducing the risk of cross-threading and installation errors. The 82° countersink angle allows for seamless flush mounting in machinery, equipment frames, and structural assemblies where protruding fasteners could interfere with operation or safety. These fully threaded screws deliver consistent clamping force across the entire 3-1/2" length, making them ideal for thick material applications in construction, manufacturing, and heavy equipment maintenance.

Specification Summary & Compliance

This 5/16"-18 UNC threaded flat head screw maintains precise Class 2A thread fit tolerances as specified in ASME B18.6.3 manufacturing standards. The inch-system dimensions include a 0.597" head diameter and 0.191" head height with standard flat head profile. The fastener meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety. The right-hand thread direction with coarse thread spacing follows industry-standard UNC specifications for reliable performance across various applications.