S-91251A595 5/16"-18 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 applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on alloy steel extends service life in harsh industrial environments.
• Precise Class 3A thread fit provides tight, secure connections with minimal backlash, enhancing assembly accuracy.
• High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• 1/4" hex drive design allows for easy installation and removal with standard tools, speeding up maintenance and assembly.
• Coarse UNC threading enables quick engagement and reduced cross-threading risks, ideal for rapid production lines.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material quality and environmental safety, meeting global regulatory standards.

Professional Applications & Engineering Value

These 5/16"-18 UNC Socket Head Cap Screws are engineered to address critical challenges in heavy-duty and precision assemblies. The black-oxide alloy steel construction provides a durable barrier against rust and oxidation, making them suitable for applications in machinery, automotive, and construction where exposure to moisture or chemicals is common. With a partially threaded design and coarse thread spacing, they offer optimal grip and vibration resistance, reducing loosening in dynamic environments. The 1/4" hex drive ensures efficient torque transmission, minimizing tool slippage and streamlining installation in confined spaces. Ideal for securing components in high-stress setups, these screws deliver consistent performance, backed by ASTM A574 specifications for reliability in demanding industrial uses.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including Class 3A thread fit for tight tolerances and UNC coarse threading with a size of 5/16"-18. Manufactured in accordance with ASTM A574, it ensures high-quality alloy steel composition. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it meets environmental and safety requirements for hazardous substances.