S-91251A857 3/4"-10 x 5 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 industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish extends service life in harsh environments, minimizing maintenance and replacement costs.
• Precise Class 3A thread fit provides secure, vibration-resistant connections, enhancing assembly integrity and safety.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• 5/8" hex drive design allows for easy installation with standard tools, speeding up assembly processes.
• Partially threaded rod configuration enables optimal clamping force distribution, ideal for applications requiring precise load management.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency and environmental safety, meeting global regulatory standards.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in heavy machinery, automotive, and construction sectors. Its UNRC coarse thread and Class 3A fit deliver superior grip and vibration resistance, preventing loosening under dynamic loads. The alloy steel material combined with a black-oxide surface treatment provides enhanced durability against moisture and chemicals, reducing corrosion-induced failures. With a tensile strength of 170,000 psi and Rockwell C37 hardness, it withstands extreme pressures and abrasion, making it ideal for bolting applications in structural frames, industrial equipment, and automotive assemblies where reliability and longevity are paramount.

Specification Summary & Compliance

This screw adheres to inch system measurements with a 3/4"-10 UNRC coarse thread and Class 3A thread fit for precise dimensional accuracy. It meets ASTM A574 specifications for high-strength socket head cap screws, ensuring consistent manufacturing quality. The product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in restricted substance-sensitive environments.