S-91030A029 5/16"-18 Flange Nuts

Key Features & Benefits at a Glance

• Integrated Flange Design: Eliminates the need for separate washers, saving assembly time and reducing component count in your projects.
• Superior Corrosion Resistance: The black-oxide steel finish provides a durable protective layer, extending the nut's service life in harsh industrial environments.
• Reliable, Coarse Thread Engagement: The UNC coarse thread with a Class 2B fit ensures easy starting, rapid installation, and consistent clamping force.
• Optimized Load Distribution: The large 3/4" flange diameter spreads clamping force over a wider area, preventing surface damage and improving joint integrity.
• Standard External Hex Drive: Allows for high-torque installation using common wrenches and sockets, facilitating efficient maintenance and assembly.
• Robust Material Strength: Made from high-quality steel, this nut is built to withstand high vibration and tensile loads in demanding applications.
• Compliant and Safe: Meets RoHS 3 directives, ensuring the product is safe for use in regulated markets and applications.

Professional Applications & Engineering Value

This heavy-duty flange nut is engineered to solve common fastening challenges in industrial settings. The black-oxide steel construction offers excellent resistance to corrosion, making it ideal for automotive assemblies, machinery frames, and outdoor equipment where exposure to moisture is a concern. The integrated flange acts as a built-in washer, which increases the bearing surface and prevents loosening under high-vibration conditions. Paired with 5/16"-18 UNC coarse threads, this nut ensures quick and secure fastening, reducing installation time and labor costs. Its Class 2B thread fit provides the optimal balance between ease of assembly and holding strength, delivering reliable performance in critical industrial fastening applications.

Specification Summary & Compliance

This flange nut features a 5/16"-18 UNC thread with a Class 2B fit for standard tolerance and easy assembly. Key dimensions include a flange diameter of 3/4", a thickness of 0.13", a width across flats of 9/16", and a height of 3/8". The product is manufactured in compliance with RoHS 3 (2015/863/EU) with exemption 6(a) for lead as an alloying element in steel.