S-91251A851 3/4"-10 x 4" 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 extends service life in harsh industrial environments, minimizing maintenance and replacement costs.
• Precise Class 3A thread fit provides tight, secure connections with minimal play, enhancing assembly integrity and vibration resistance.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated installations and removals.
• 5/8" hex drive design allows for high-torque application with standard tools, speeding up installation and reducing labor time.
• Coarse UNRC threading enables quick assembly and disassembly while providing strong holding power in various materials.
• Environmental compliance with RoHS 3 and REACH standards ensures safe use in regulated industries and global markets.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw delivers critical engineering advantages for heavy-duty industrial applications. The combination of ASTM A574 compliance and 170,000 psi tensile strength makes it ideal for high-stress assemblies in machinery, automotive, and construction equipment where vibration resistance and load-bearing capacity are paramount. The partially threaded design provides optimal clamping force distribution, while the coarse 3/4"-10 UNRC threads ensure rapid installation in tough materials. The black-oxide surface treatment significantly enhances corrosion protection without compromising dimensional accuracy, solving common durability issues in exposed or humid operating environments. These features make it particularly valuable for precision equipment, structural frames, and maintenance applications requiring reliable, long-lasting fastening solutions.

Specification Summary & Compliance

This socket head cap screw features Class 3A thread fit for precision tolerance, 3/4"-10 UNRC coarse threads with right-hand direction, and partial threading with minimum 2" thread length. Manufacturing specifications meet ASTM A574 standards for alloy steel socket head cap screws. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industrial sectors.