Flange Nut

A flange nut integrates a washer-like flange beneath the hexagonal body to enlarge its bearing surface. This design reduces the need for a separate washer in machinery, sheet-metal, and automotive assemblies, simplifying handling and potentially improving load distribution. The flange spreads bearing pressure over a wider area, which can help prevent damage to softer materials and reduce the risk of loosening under vibration, especially when serrations are present on the flange face.

For procurement, buyers must specify critical parameters such as flange diameter, serrated or smooth face, thread size, property class, material, and coating. These details must be confirmed against the applicable standard, typically ISO 4161:2012, which covers flange nuts with nominal sizes from M5 to M20. The standard defines specific dimensional and mechanical requirements, but it does not guarantee interchangeability of sizes, materials, or finishes across different manufacturers. Therefore, the request for quotation (RFQ) should clearly state the exact standard or drawing, the required configuration, quantity, and inspection evidence.

Materials commonly available include steel and stainless steel, but the final choice depends on the service environment and the property class matched to the bolt and application. Surface finishes may be plain, zinc-plated, or a specified coating, all of which must be verified against the standard and supplier documentation.

Always verify model-specific values and standards with the legal manufacturer or supplier before ordering. The information provided here serves as a general reference and does not constitute a certification or guarantee of compliance.

Thread preload clamps the joint while the integrated flange spreads bearing pressure over a larger area. This reduces surface stress on the mating part and can improve resistance to loosening. Serrations on the flange face may increase friction and provide additional resistance to rotation, especially in applications subject to vibration. The working principle relies on proper torque application to achieve the required preload, which must be matched to the property class and service conditions.