S-91251A730 1/2"-13 x 4 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.
• Superior corrosion resistance with black-oxide coating on alloy steel extends service life in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure fastening and vibration resistance in machinery assemblies.
• Hex socket drive design allows for high-torque installation with standard 3/8" tools, minimizing stripping and improving assembly efficiency.
• Partially threaded shank offers optimal grip length control, preventing over-tightening and distributing clamp load effectively.
• Rockwell C37 hardness maintains structural integrity under repeated loads, ensuring long-term durability.
• Coarse UNC threads enable quick installation and are less prone to clogging in dirty or debris-filled applications.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery manufacturing, automotive assemblies, and structural frameworks. The combination of high tensile strength and Rockwell C37 hardness ensures that the fastener can withstand extreme mechanical stresses without deforming or shearing. The 1/2"-13 UNC coarse thread with a Class 3A fit provides superior holding power and vibration resistance, reducing maintenance needs in dynamic environments. The black-oxide surface treatment not only enhances corrosion resistance but also minimizes galling during installation, making it ideal for applications where reliability and longevity are paramount. Its partial threading allows for precise clamp load distribution, preventing joint loosening in critical assemblies.

Specification Summary & Compliance

This socket head cap screw features a 1/2"-13 UNC coarse thread with Class 3A thread fit for high precision and a partially threaded design. It meets ASTM A574 specifications for high-strength alloy steel fasteners and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, ensuring safe and sustainable use in industrial applications.