S-91306A391 5/16"-18 x 1" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated alloy steel construction, ideal for harsh industrial environments
• Exceptional load-bearing capacity thanks to 120,000 psi tensile strength and Rockwell C39 hardness
• Precise, reliable fastening ensured by Class 3A thread fit for minimal backlash and secure connections
• Easy installation and removal with 3/16" hex drive, reducing assembly time and tool wear
• Full-thread engagement along the 1" length for maximum grip and uniform stress distribution
• Broad compatibility with UNC coarse threading, suitable for a wide range of materials and applications
• Regulatory peace of mind with compliance to RoHS 3 and REACH environmental standards

Professional Applications & Engineering Value

Engineered for demanding environments, these 5/16"-18 UNC zinc-plated alloy steel rounded head screws deliver exceptional durability where corrosion resistance and high tensile strength are critical. The Class 3A thread fit and coarse UNC threading provide reliable performance in vibration-prone assemblies, reducing the risk of loosening in machinery, structural frameworks, and heavy equipment. The button head design offers a low-profile finish while the fully threaded 1" length ensures consistent clamping force. Ideal for industrial maintenance, automotive systems, and construction projects, these screws meet ASME B18.3 and ASTM F835 specifications, guaranteeing interchangeability and long-term reliability under 120,000 psi loads.

Specification Summary & Compliance

This screw features a 5/16"-18 UNC coarse thread with Class 3A precision fit, ensuring tight tolerances and secure fastening. Manufactured from zinc-plated alloy steel with a rounded (button) head and 3/16" hex drive, it complies with ASME B18.3 and ASTM F835 standards. The product is fully RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, meeting environmental and safety regulations for industrial use.