S-91236A601 5/16"-18 x 4 1/2" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating that protects against rust and extends service life in demanding environments
• High tensile strength of 60,000 psi ensures reliable performance under heavy loads and prevents fastener failure
• Rockwell B69 hardness provides excellent durability and resistance to wear during repeated installation and removal
• External hex drive design allows for easy installation with standard tools and secure torque application
• Coarse UNC threading enables quick assembly and reduces cross-threading risks in industrial applications
• Class 2A thread fit offers consistent, precision threading for smooth engagement and reliable connections
• Partial threading provides optimal grip length for materials where full threading isn't required, improving installation efficiency

Professional Applications & Engineering Value

This 5/16"-18 UNC hex head screw delivers exceptional engineering value through its steel construction and zinc plating, specifically designed to address common industrial challenges. The combination of 60,000 psi tensile strength and Rockwell B69 hardness ensures reliable performance in structural applications, machinery assembly, and heavy equipment where vibration resistance is critical. The coarse thread design prevents binding in softer materials while the external hex drive accommodates high torque requirements. As a partially threaded fastener, it provides secure clamping without unnecessary threading, making it ideal for construction, manufacturing, and maintenance applications requiring robust, long-lasting connections that withstand environmental stressors.

Specification Summary & Compliance

This 4-1/2" hex head screw features precision Class 2A thread fit with 5/16"-18 UNC coarse threading and right-hand thread direction. Manufactured to ASME B18.2.1 specifications and ASTM A307 standards, it ensures dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting environmental and safety requirements for industrial use across various sectors.