S-91251A592 5/16"-18 x 2 1/4" 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 applications, reducing the risk of fastener failure.
• Black-oxide coating on alloy steel provides enhanced corrosion resistance, extending service life in harsh industrial environments.
• Class 3A thread fit offers superior precision and tight tolerances for secure, vibration-resistant assemblies.
• Partially threaded design with coarse UNC threads allows for easier alignment and faster installation, saving valuable assembly time.
• Rockwell C37 hardness delivers excellent wear resistance, maintaining thread integrity through repeated use.
• 1/4" hex drive socket head enables high-torque application with standard tools, minimizing stripping and improving installation efficiency.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety for global industrial standards.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these Black-Oxide Alloy Steel Socket Head Cap Screws address critical challenges in machinery, automotive, and heavy equipment assembly. The coarse UNC thread and Class 3A fit ensure rapid, secure fastening even in high-vibration environments, reducing maintenance needs. The partially threaded rod design provides optimal clamping force distribution, preventing joint loosening. With a 170,000 psi tensile strength and Rockwell C37 hardness, these screws withstand extreme loads and abrasive conditions, making them ideal for high-stress applications where reliability is non-negotiable. The black-oxide surface treatment further enhances durability by resisting rust and corrosion, ensuring long-term performance in outdoor or humid operations.

Specification Summary & Compliance

This socket head cap screw meets precise dimensional standards, including Class 3A thread fit for tight tolerances and UNC coarse threading with a size of 5/16"-18. Manufacturing adheres to ASTM A574 specifications, ensuring consistent quality and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in regulated industries without environmental or health concerns.