S-90058A583 5/16"-18 x 1" Tamper-Resistant Tri-Groove-Drive Steel Round Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc-plated steel construction for long-lasting performance in harsh environments
• Superior torque transmission through Tri-Groove drive design, reducing cam-out and tool slippage during installation
• Precise thread engagement with Class 3A fit ensuring reliable, vibration-resistant connections in critical assemblies
• High tensile strength rating of 80,000 psi provides dependable load-bearing capacity for heavy-duty applications
• Optimized hardness profile at Rockwell C28 balances durability with necessary ductility for secure fastening
• Full threading coverage along the 1" length maximizes grip range and installation flexibility
• Coarse UNC thread pattern enables quick assembly and superior performance in softer materials

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these zinc-plated steel screws combine material strength with advanced drive technology to solve critical fastening challenges. The Tri-Groove drive system delivers exceptional torque transfer while minimizing strip-out incidents that plague traditional fasteners in high-vibration settings. With Class 3A thread fit and coarse UNC threading, these fasteners provide reliable performance in structural assemblies, machinery frames, and equipment where vibration resistance is paramount. The 80,000 psi tensile strength and Rockwell C28 hardness ensure these rounded head screws maintain integrity under sustained loads while the zinc plating offers essential corrosion protection for extended service life in manufacturing, construction, and heavy equipment applications.

Specification Summary & Compliance

This 5/16"-18 x 1" screw features precision UNC coarse threads with Class 3A fit tolerance for superior engagement. Manufacturing complies with applicable industry standards for dimensional accuracy, including proper head diameter (0.57"), head height (0.275"), and thread diameter (0.313") specifications. The fully threaded design with right-hand thread direction and No. 20 Tri-Groove drive ensures consistent performance. Materials and plating processes conform to RoHS and REACH environmental compliance requirements.