S-98858A102 5/16"-18 Cap Nuts

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with Grade 5 strength classification, ensuring reliable performance in high-stress industrial applications
• Superior corrosion protection through zinc-plated steel construction, extending service life in demanding environments
• Precision thread engagement with Class 2B fit and UNC coarse threads, providing consistent clamping force and vibration resistance
• Optimized installation efficiency featuring external hex drive design for standard wrench compatibility and secure tightening
• Enhanced safety and containment with full-cap nut profile, effectively sealing threaded ends and preventing fluid ingress
• Regulatory compliance assurance meeting RoHS 3 standards for environmentally responsible manufacturing
• Robust dimensional stability with 1/2" width and 17/32" height maintaining structural integrity under repeated use

Professional Applications & Engineering Value

This Grade 5 zinc-plated steel cap nut delivers critical engineering solutions where corrosion resistance and structural reliability are paramount. The 5/16"-18 UNC coarse thread configuration ensures rapid assembly in heavy machinery, construction equipment, and automotive systems, while the Class 2B thread fit maintains precise tolerances for vibration-prone environments. The external hex drive facilitates high-torque installation using standard tools, and the full-cap design provides essential protection against contamination in hydraulic systems and exposed mechanical assemblies. Manufactured from zinc-plated steel, this industrial fastener combats oxidation in outdoor and high-moisture applications, delivering long-term performance where ordinary fasteners would degrade.

Specification Summary & Compliance

This cap nut features 5/16"-18 UNC coarse threads with Class 2B thread fit per ASME B1.1 standards, ensuring precise dimensional accuracy and interchangeability. The zinc-plated steel construction meets Grade 5 mechanical properties (approximately 120,000 psi tensile strength) with a standard external hex drive configuration. Compliant with RoHS 3 (2015/863/EU) regulations under exemption 6(a)-I for lead as steel alloying element. Dimensions include 1/2" width across flats and 17/32" total height for consistent installation clearances.