S-90299A581 5/16"-18 x 3/4" ASME B18.3, ASTM A574 Brass-Tip Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Prevents surface damage with a nonmarring brass tip, ideal for applications requiring scratch-free assembly on sensitive materials.
• Exceptional tensile strength of 180,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide coating on alloy steel, extending service life in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant connections in critical assemblies.
• Easy installation and removal with a standard 1/4" hex drive socket head, allowing for high torque application in confined spaces.
• Durable Rockwell C39 hardness maintains structural integrity and resists wear over repeated use.
• Coarse UNC threads enable quick assembly and disassembly, improving efficiency in maintenance and production lines.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges, such as surface marring and corrosion in demanding environments. The nonmarring brass tip eliminates damage to soft or finished surfaces, making it ideal for precision machinery, automotive components, and electronic enclosures where aesthetics and integrity are critical. With a fully threaded design and Class 3A thread fit, it ensures consistent clamping force and vibration resistance, reducing loosening in high-load applications. The combination of 180,000 psi tensile strength and corrosion-resistant coating provides long-term reliability, supporting heavy-duty use in construction, aerospace, and manufacturing sectors without compromising on compliance or performance.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including 5/16"-18 UNC coarse threads with a Class 3A fit for superior accuracy. It meets ASME B18.3 and ASTM A574 specifications, ensuring consistent manufacturing quality. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it is free from hazardous substances, supporting safe and sustainable industrial use.