S-91236A591 5/16"-18 x 2" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior Corrosion Resistance: Zinc plating provides a durable protective barrier, extending service life in demanding industrial environments.
• High Tensile Strength: Rated at 60,000 psi, this screw reliably withstands high-stress applications without failure.
• Optimized Thread Design: The UNC coarse threadClass 2A fit ensure rapid installation and a secure, vibration-resistant hold.
• Robust Material Hardness: Rockwell B69 hardness provides excellent resistance to wear and deformation under load.
• Efficient External Hex Drive: The standard 1/2" hex head allows for high-torque application with common tools, speeding up assembly.
• Versatile Partially Threaded Shank: The design provides a strong, unthreaded grip length for enhanced shear strength in structural connections.
• Guaranteed Compliance & Quality: Manufactured to meet ASME B18.2.1 and ASTM A307 specifications, ensuring dimensional accuracy and performance reliability.

Professional Applications & Engineering Value

Engineered for heavy-duty fastening, this 5/16"-18 UNC hex head screw is a cornerstone for industrial assembly and construction. The combination of steel material and zinc plating directly addresses the common failure point of corrosion in machinery, outdoor structures, and metal framing. The coarse UNC thread is specifically advantageous for quick assembly into softer materials or castings, reducing cross-threading risks and installation time. Its 60,000 psi tensile strength and Rockwell B69 hardness provide the necessary margin of safety for high-vibration environments and load-bearing applications, from securing heavy equipment to assembling transportation components. This screw delivers predictable performance and long-term reliability, minimizing maintenance and downtime.

Specification Summary & Compliance

This product adheres to critical dimensional and performance standards, including a Class 2A thread fit for consistent assembly and the manufacturing specifications of ASME B18.2.1 and ASTM A307. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in regulated markets and environmentally conscious supply chains.