S-91251A174 1 1/8"-7 x 7" 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 industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish prolongs service life in demanding environments, minimizing maintenance needs.
• High hardness rating (Rockwell C37) provides excellent wear resistance, maintaining thread integrity through repeated use.
• Coarse UNRC threads enable faster installation and better debris clearance, speeding up assembly processes.
• Partially threaded design offers precise clamping control where full thread engagement isn't required, improving joint stability.
• 7/8" hex drive allows for high torque application with standard tools, ensuring secure fastening without stripping.
• Compliance with ASTM A574 guarantees consistent quality and mechanical properties for critical engineering applications.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw delivers exceptional engineering value through its optimized material properties and thread design. The alloy steel construction combined with Rockwell C37 hardness addresses common industrial challenges of vibration-induced loosening and material fatigue in heavy machinery, construction equipment, and automotive assemblies. The coarse UNRC threads provide superior performance in applications where fine debris or corrosion might compromise thread engagement, while the partially threaded configuration ensures precise clamping force distribution in structural connections. The black-oxide surface treatment offers enhanced corrosion protection without significantly altering dimensional tolerances, making these socket head cap screws ideal for OEM manufacturing and maintenance operations requiring reliable, high-strength fastening solutions.

Specification Summary & Compliance

This socket head cap screw maintains Class 2A thread fit tolerances for consistent engagement and features 1 1/8"-7 UNRC coarse threads with a minimum thread length of 2 7/8". Manufactured in compliance with ASTM A574 specifications for socket head cap screws, the fastener also meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards, ensuring suitability for global industrial applications.