S-90128A167 7/8"-9 x 3" 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 zinc plating extends service life and maintains integrity in harsh or outdoor environments.
• Precise Class 3A thread fit provides tight, secure fastening with minimal backlash, ideal for precision assemblies.
• Heavy-duty alloy steel construction with Rockwell C37 hardness offers excellent durability and resistance to wear and deformation.
• Coarse UNC threading allows for quicker installation and better performance in materials prone to debris or vibration.
• Partially threaded design enables controlled clamping force and prevents over-tightening in specific joint configurations.
• Compliance with ASTM A574, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations for safe, global use.

Professional Applications & Engineering Value

Engineered for demanding environments, these zinc-plated alloy steel socket head cap screws deliver robust performance in heavy machinery, construction equipment, and automotive assemblies. The UNC coarse thread and Class 3A fit provide superior resistance to loosening under vibration, a common challenge in dynamic applications. With a 170,000 psi tensile strength and Rockwell C37 hardness, they withstand extreme loads without stripping or shearing, reducing maintenance downtime. The hex drive and standard socket head profile facilitate easy installation in confined spaces, while the zinc plating combats corrosion, ensuring long-term reliability in both indoor and outdoor settings. Ideal for structural frames, hydraulic systems, and high-torque fixtures, these screws offer a dependable solution for critical fastening needs.

Specification Summary & Compliance

This socket head cap screw features a 7/8"-9 UNC coarse thread with Class 3A thread fit for precise dimensional accuracy, ensuring consistent performance. It meets ASTM A574 specifications for high-strength alloy steel fasteners, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental safety and global supply chain requirements.