S-90058A580 5/16"-18 x 5/8" Tamper-Resistant Tri-Groove-Drive Steel Round Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc-plated steel construction, ensuring long-lasting performance in harsh industrial environments.
• Superior holding power from fully threaded design and 80,000 psi tensile strength, providing reliable fastening in high-stress applications.
• Precise thread engagement with Class 3A thread fit and UNC coarse threads, reducing cross-threading risks and enabling quick assembly.
• Enhanced durability with Rockwell C28 hardness, maintaining structural integrity under repeated loads and vibrations.
• Efficient installation using the Tri-Groove drive style and No. 20 drive size, minimizing cam-out and tool slippage for consistent torque application.
• Versatile rounded head profile with a high, rounded design, offering a smooth finish that reduces snagging and improves safety in exposed applications.
• Broad compatibility with standard 5/16"-18 UNC coarse threading, making it ideal for replacement or new assemblies in machinery and equipment.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these zinc-plated steel rounded head screws combine high tensile strength and Class 3A thread fit to address common fastening challenges like vibration loosening and corrosion. The UNC coarse threads facilitate rapid installation in metals and plastics, while the Tri-Groove drive ensures secure torque transfer, reducing downtime in assembly lines. Ideal for heavy-duty machinery, automotive components, and construction equipment, they provide a reliable solution where fully threaded designs enhance grip and distribute stress evenly, prolonging service life in high-load environments.

Specification Summary & Compliance

This screw adheres to UNC coarse thread standards with precise Class 3A thread fit for consistent performance. Dimensions include a 5/16"-18 thread size, 5/8" length, and 0.57" head diameter, manufactured under strict quality controls. It meets industry specifications for material and threading, with compliance to relevant standards such as ASME for mechanical fasteners, and is free from hazardous substances in line with RoHS and REACH directives.