S-91251A008 5/16"-18 x 7 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Durable black-oxide coating on alloy steel provides enhanced corrosion resistance, extending service life in harsh industrial environments.
• Class 3A thread fit offers superior precision and tighter tolerances for secure, vibration-resistant assemblies.
• Partially threaded design allows for controlled clamping force and easier alignment in complex machinery setups.
• 1/4" hex drive socket head enables high-torque installation with standard tools, minimizing stripping and improving efficiency.
• Rockwell C37 hardness ensures excellent wear resistance, maintaining integrity under repetitive loads.
• Coarse UNRC threads facilitate quick assembly and disassembly, saving time in maintenance and production cycles.

Professional Applications & Engineering Value

This 5/16"-18 Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in heavy-duty industrial applications, such as machinery assembly, automotive systems, and construction equipment. The alloy steel construction, combined with the black-oxide surface treatment, provides robust protection against rust and wear, even in demanding environments with exposure to moisture and chemicals. The partially threaded rod and coarse UNRC thread design ensure rapid installation and reliable grip, reducing assembly time while preventing loosening under vibration. With a high tensile strength and precise Class 3A thread fit, this fastener delivers consistent performance in applications requiring superior clamping force and durability, making it an ideal choice for engineers and procurement specialists seeking long-term reliability and compliance with industry standards.

Specification Summary & Compliance

This socket head cap screw features a 5/16"-18 thread size with UNRC coarse threads and a Class 3A thread fit for high precision. It complies with ASTM A574 specifications, ensuring consistent quality and performance. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use.