S-91236A594 5/16"-18 x 2 3/4" 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 harsh industrial environments.
• High tensile strength of 60,000 psi ensures reliable load-bearing capacity for demanding applications.
• Rockwell B69 hardness provides excellent durability and resistance to wear and deformation.
• Coarse UNC thread with Class 2A fit offers quick assembly and secure fastening, reducing installation time.
• Partially threaded design allows for precise clamping force control and vibration resistance.
• External hex drive and hex head enable easy installation and removal with standard tools.
• Compliance with ASME B18.2.1 and ASTM A307 guarantees consistent quality and interchangeability.

Professional Applications & Engineering Value

This 5/16"-18 UNC hex head screw is engineered to address critical fastening challenges in industrial assembly, construction, and heavy machinery. The steel material combined with zinc plating provides a robust barrier against rust and corrosion, making it ideal for outdoor or humid conditions. Its partially threaded configuration ensures that unthreaded sections bear against materials, minimizing loosening from vibrations—a common issue in dynamic loads. With a coarse thread and Class 2A fit, it delivers rapid installation and reliable grip in wood, metal, or composite substrates, reducing labor costs and enhancing structural integrity in frameworks, equipment mounts, and infrastructure projects.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including a Thread Fit of Class 2A and UNC thread type with coarse spacing for consistent performance. It meets ASME B18.2.1 and ASTM A307 specifications, ensuring high manufacturing quality. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in regulated industries without hazardous substances.