S-91991A102 5/16"-18 Hex Nuts

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide steel coating, extending service life in harsh industrial environments.
• Enhanced grip and torque application from the extra wide hex profile, reducing tool slippage and speeding up assembly.
• Reliable thread engagement with Class 2B fit and coarse UNC threading, ensuring consistent performance and easier installation.
• High-strength construction for heavy-duty applications, providing dependable load-bearing capacity and vibration resistance.
• Compliance with global standards including RoHS 3 and REACH, making it suitable for regulated industries and export requirements.
• Right-hand thread design for standard installation, compatible with common tools and reducing assembly errors.
• Dimensional accuracy in inch measurements (9/16" width, 19/64" height), ensuring precise fit with matching components.

Professional Applications & Engineering Value

This heavy-duty hex nut is engineered to address common industrial challenges such as corrosion, vibration loosening, and assembly inefficiency. The black-oxide steel material provides a durable barrier against moisture and chemicals, ideal for outdoor machinery, automotive assemblies, and construction equipment. Its extra wide profile offers a larger contact surface, distributing stress evenly and allowing for higher torque application without damaging the fastener. The coarse UNC thread and Class 2B thread fit ensure quick, secure fastening in high-vibration environments, reducing maintenance needs and downtime. By integrating this 5/16"-18 UNC hex nut into your designs, you achieve reliable, long-lasting connections that meet rigorous industrial demands while complying with environmental regulations.

Specification Summary & Compliance

This hex nut adheres to UNC coarse thread standards with a Class 2B thread fit for consistent dimensional accuracy. Manufactured in the inch system, it features a right-hand thread direction and external hex drive style. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for global industrial supply chains.