S-91309A583 5/16"-18 x 1" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating, extending service life in demanding industrial environments
• High tensile strength of 60,000 psi ensures reliable, heavy-duty fastening for critical applications
• Coarse UNC threading provides faster installation and better performance in softer materials
• External hex drive design allows for high-torque application with standard tools
• Class 2A thread fit guarantees consistent, precise mating with nuts and tapped holes
• Full threading along the 1" length offers maximum grip and adjustability
• Rockwell B69 hardness maintains structural integrity under stress and vibration

Professional Applications & Engineering Value

These 5/16"-18 x 1" steel hex head screws are engineered to address common industrial fastening challenges, including vibration loosening and corrosion-induced failure. The zinc plated finish provides a protective barrier against moisture and chemicals, significantly reducing maintenance needs in harsh environments. With coarse UNC threading and Class 2A fit, they deliver superior holding power in structural assemblies, machinery, and equipment where high tensile strength (60,000 psi) is critical. The external hex drive enables efficient installation with common wrenches, streamlining assembly processes in manufacturing, construction, and maintenance applications requiring dependable, long-lasting fasteners.

Specification Summary & Compliance

This screw features precise Class 2A thread fit with UNC coarse threading (5/16"-18) and complies with ASME B18.2.1 manufacturing specifications where identified as ASTM A307. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions are met for industrial use.