S-91251A169 1 1/8"-7 x 5" 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.
• Superior corrosion resistance from the black-oxide finish on alloy steel extends service life and maintains integrity in harsh industrial environments.
• Precise Class 2A thread fit with coarse UNRC threads allows for easier, faster assembly and disassembly while maintaining secure connections.
• Robust 7/8" hex drive design provides high torque capability and reduces stripping, enabling efficient installation with standard tools.
• Partially threaded shank offers optimal grip and clamping force control, ideal for applications requiring precise joint security.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency, environmental safety, and adherence to international quality standards.
• Rockwell C37 hardness ensures excellent wear resistance and durability, minimizing deformation over repeated use cycles.

Professional Applications & Engineering Value

Engineered for high-strength industrial applications, these black-oxide alloy steel socket head cap screws address critical challenges in machinery assembly, automotive systems, and heavy equipment. The coarse UNRC thread design facilitates quick installation in materials prone to vibration loosening, while the 1 1/8"-7 thread size and 5" length provide ample engagement for structural integrity. The black-oxide surface treatment not only enhances corrosion resistance but also reduces galling, making these fasteners suitable for outdoor or chemically exposed environments. With a partially threaded configuration, they ensure precise clamping without over-tightening, solving common issues of joint fatigue and misalignment in B2B procurement scenarios where reliability and compliance with ASTM A574 are paramount.

Specification Summary & Compliance

This socket head cap screw features a Class 2A thread fit with UNRC coarse threads, ensuring dimensional accuracy per inch system standards. Manufacturing adheres to ASTM A574 specifications for alloy steel socket head cap screws, guaranteeing consistent mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming the absence of restricted substances and supporting sustainable industrial practices.