S-91251A270 6-32 x 1 7/8" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Corrosion-resistant black-oxide finish on alloy steel provides enhanced durability and longevity, ideal for industrial environments where moisture and chemicals are present.
• Precise Class 3A thread fit guarantees tight, secure connections with minimal play, improving assembly accuracy and reducing the need for rework.
• Hex socket drive design allows for high torque application and easy installation in confined spaces, increasing efficiency during maintenance or assembly.
• Partially threaded shank offers flexibility for applications requiring unthreaded grip length, preventing thread damage and ensuring proper clamping force.
• Compliance with ASTM A574, RoHS 3, and REACH standards ensures material consistency, environmental safety, and suitability for regulated industries.
• Coarse UNC threads enable quick assembly and disassembly, saving time in production and repair operations while maintaining strong holding power.

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws are engineered to address common industrial challenges such as vibration loosening, corrosion, and high-load demands. The 6-32 UNC coarse thread design, combined with a Class 3A fit, ensures secure fastening in machinery, automotive assemblies, and electronic enclosures where precision and reliability are critical. The partially threaded configuration allows the unthreaded portion to act as a dowel, minimizing shear stress and distributing load evenly. With a Rockwell C37 hardness and robust 170,000 psi tensile strength, these screws resist wear and deformation, making them ideal for repetitive use in manufacturing equipment, aerospace components, and heavy-duty frameworks. The hex drive facilitates easy installation with standard tools, reducing assembly time and enhancing productivity in high-volume operations.

Specification Summary & Compliance

This product adheres to Class 3A thread fit tolerances per UNC standards, ensuring precise engagement and consistent performance. Manufacturing complies with ASTM A574 specifications for alloy steel socket head cap screws, guaranteeing material integrity and mechanical properties. Environmental and safety standards include full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming the absence of restricted substances and supporting sustainable procurement practices.