S-99891A205 1 1/4"-7 Hex Nuts

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with Grade 8 strength rating, ensuring reliable performance in high-stress industrial applications.
• Superior corrosion resistance from zinc yellow-chromate plating, extending service life in harsh or outdoor environments.
• Secure left-hand threading for specialized assemblies where reverse rotation prevents loosening under counter-clockwise motion.
• Precise Class 2B thread fit for smooth engagement and consistent clamping force without cross-threading risks.
• Coarse UNC threads (1 1/4"-7) enabling faster installation and reduced susceptibility to debris clogging in rugged settings.
• Standard external hex drive design for universal compatibility with common wrenches, streamlining maintenance and assembly workflows.
• Heavy-duty inch-dimensioned build (1 7/8" width, 1 1/16" height) offering robust mechanical stability for demanding structural connections.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial systems, this Grade 8 steel hex nut addresses critical challenges in machinery, construction, and transportation sectors. Its left-hand UNC coarse threading is ideal for rotating components—such as shafts, presses, or mixer assemblies—where standard right-hand threads may loosen due to operational torque. The zinc yellow-chromate plating combats oxidation and chemical exposure, reducing maintenance frequency in corrosive settings like marine or chemical processing plants. Combined with a Class 2B thread fit, it ensures vibration-resistant connections without galling, supporting long-term integrity in high-vibration environments. The external hex drive simplifies installation with standard tools, minimizing downtime during repairs or upgrades.

Specification Summary & Compliance

This hex nut adheres to UNC coarse thread standards (1 1/4"-7) with a Class 2B thread fit for consistent dimensional accuracy. Manufactured from Grade 8 steel, it meets ASME/ANSI mechanical property requirements for high-strength fasteners. The zinc yellow-chromate finish complies with RoHS and REACH directives, ensuring environmental safety. All dimensions follow the inch system, including a 1 7/8" width and 1 1/16" height, guaranteeing interoperability with matched left-hand threaded components.