S-91251A198 8-32 x 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.
• Class 3A thread fit provides superior precision and tighter tolerances for secure, vibration-resistant assemblies in demanding applications.
• Black-oxide coating on alloy steel offers enhanced corrosion resistance and a durable, non-reflective finish suitable for harsh industrial environments.
• Rockwell C37 hardness delivers excellent wear resistance and long-term durability, minimizing wear and deformation during repeated use.
• Hex socket drive (9/64") allows for high-torque installation with standard tools, ensuring easy assembly and disassembly without stripping.
• 8-32 UNC coarse thread enables quick installation and superior grip in a wide range of materials, improving assembly efficiency.
• Full compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency, environmental safety, and adherence to international industrial standards.

Professional Applications & Engineering Value

Engineered for high-performance industrial applications, these black-oxide alloy steel socket head cap screws address critical challenges in machinery, automotive, and heavy equipment assembly. The UNC coarse thread and Class 3A fit ensure precise, secure fastening that resists loosening under vibration and dynamic loads. With a 170,000 psi tensile strength and Rockwell C37 hardness, they provide reliable clamping force and durability in high-stress environments, reducing maintenance needs and downtime. The black-oxide finish adds corrosion protection, making them ideal for both indoor and outdoor use where exposure to moisture or chemicals is a concern. These screws are a trusted solution for engineers seeking ASTM A574 compliant fasteners that combine strength, precision, and regulatory compliance.

Specification Summary & Compliance

This socket head cap screw features an 8-32 UNC coarse thread with Class 3A thread fit for high precision, and is fully threaded with a length of 7/8". It meets ASTM A574 specifications for alloy steel socket head cap screws, ensuring consistent material and mechanical properties. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming adherence to environmental and safety regulations for industrial use.