S-91251A728 1/2"-13 x 4" 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.
• Black-oxide coating on alloy steel provides enhanced corrosion resistance and a durable, non-reflective finish for extended service life.
• Class 3A thread fit offers superior precision and tighter tolerances for secure, vibration-resistant assemblies in critical machinery.
• Hex socket drive (3/8") allows for high-torque installation with standard tools, enabling efficient assembly in confined spaces.
• Partially threaded design with 1-1/2" thread engagement provides optimal clamping force and alignment in structural applications.
• Rockwell C37 hardness ensures excellent wear resistance and durability under repetitive loading conditions.
• Coarse UNC threads facilitate quick installation and are less prone to clogging in dirty or high-vibration environments.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges such as vibration loosening, corrosion, and high mechanical stress. The 1/2"-13 UNC coarse thread design ensures rapid assembly and reliable holding power in heavy machinery, automotive systems, and construction equipment. With a 170,000 PSI tensile strength and Rockwell C37 hardness, it withstands extreme loads and repetitive motion, minimizing maintenance downtime. The hex drive and partially threaded shank provide precise torque control and secure fastening in tight spaces, making it ideal for high-strength bolting applications where safety and durability are paramount.

Specification Summary & Compliance

This socket head cap screw features a 1/2"-13 UNC coarse thread with Class 3A fit for precise dimensional accuracy. It meets ASTM A574 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global industrial markets.