S-90983A206 5/16"-18 x 7/8" Coupling Nuts

Key Features & Benefits at a Glance

• Exceptional tensile strength with Grade 8 classification ensures reliable performance in high-stress applications and prevents premature failure
• Superior corrosion resistance from zinc plating protects against rust and extends service life in harsh industrial environments
• Precise Class 2B thread fit guarantees smooth assembly and secure connections with mating components
• Heavy-duty construction with full UNC coarse threading provides maximum load distribution and vibration resistance
• Standard external hex drive enables easy installation using common wrenches while maintaining structural integrity
• Full regulatory compliance with RoHS 3 and REACH standards ensures environmental responsibility and global market acceptance
• Optimized dimensions (1/2" width × 7/8" length) offer ideal balance between strength requirements and space constraints

Professional Applications & Engineering Value

This Grade 8 zinc-plated steel coupling nut delivers critical engineering solutions for demanding mechanical systems where extended thread engagement is required. The UNC coarse threading with Class 2B fit ensures rapid assembly while maintaining precise alignment in structural frameworks, machinery assemblies, and heavy equipment. The zinc-plated steel construction combats corrosion in industrial environments, significantly reducing maintenance frequency and replacement costs. With its full threading and external hex drive, this coupling nut provides uniform stress distribution and accessible installation in confined spaces, making it ideal for connecting threaded rods, studs, or other fasteners in construction, automotive, and manufacturing applications where vibration resistance and long-term reliability are paramount.

Specification Summary & Compliance

This coupling nut features 5/16"-18 UNC coarse threads with Class 2B thread fit per standard inch system requirements, ensuring dimensional accuracy and interchangeability. Manufactured from high-strength steel with zinc plating surface treatment, the fastener meets Grade 8 strength classification for heavy-duty applications. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, containing no restricted substances above threshold limits as of the current SVHC list (01/17/2022).