Thick Hex Flange Nuts, Yellow Zinc Plated

Core Features

Enlarged Flange Base – The flange is integrally formed with the nut body, eliminating the need for a separate washer and providing a fixed bearing surface that does not shift during assembly.

Increased Nut Height – The body thickness is dimensionally greater than standard flange nuts, providing extended thread engagement length and additional load-bearing capacity for the threaded connection.

Yellow Zinc Plated Coating – The coating provides a barrier layer against corrosion through zinc sacrificial protection and chromate conversion treatment, with a yellow iridescent finish for visual identification.

Serrated Underside Design – The flange underside incorporates serrations that create mechanical interference with the mating surface during tightening, generating prevailing torque for locking action.

Product Characteristics

The fastener is produced in accordance with dimensional and mechanical specifications defined in applicable standards. Thread dimensions and tolerances follow standard metric thread profiles. The flange outside diameter and thickness are dimensioned to provide load distribution across the bearing surface. The increased nut height provides greater thread engagement compared to standard flange nut configurations.

Material composition and heat treatment processes are regulated to meet the mechanical property requirements for specified performance grades. Performance grade 8 offers a defined proof load and tensile strength range, while grades 10 and 12 provide increased strength for heavy-duty applications. Stainless steel grade A2-70 offers corrosion resistance for general environmental exposure.

The yellow zinc plating is applied through an electroplating process followed by chromate conversion coating. Coating thickness is maintained within defined tolerances to ensure thread fit and consistent flange contact geometry.

Application Scenarios

Heavy Equipment Manufacturing – Used in construction machinery, agricultural equipment, and mining vehicles where higher clamping loads and vibration resistance are required. The increased nut height provides additional thread engagement for load-carrying capacity.

Structural Steel Connections – Applied in building and bridge construction where flange load distribution across structural members reduces surface indentation and the yellow zinc finish provides corrosion protection for outdoor exposure.

Automotive and Transportation – Used in chassis and suspension systems, frame assemblies, and powertrain components where the integrated flange simplifies assembly and the serrated locking feature addresses vibration-related loosening.

Industrial Machinery – Employed in gearbox assemblies, pump housings, and motor mounts where flange load distribution reduces localized stress on bearing surfaces.

Customization Options

Specifications and configurations can be adjusted based on application requirements. Material grades include carbon steel grades for general mechanical applications and stainless steel grades A2 and A4 for corrosion-resistant requirements. Surface treatments are selectable according to environmental exposure conditions, including zinc plating with alternative chromate finishes, zinc flake coating, nickel plating, chrome plating, and phosphate coating. Strength grades can be matched to specific tensile and yield strength criteria defined in application engineering specifications.

Frequently Asked Questions

Q: What is the difference between a standard flange nut and a thick flange nut?
A: A thick flange nut has an increased nut height (body thickness) compared to standard flange nuts, providing greater thread engagement and increased load-carrying capacity for the threaded connection. The larger flange base provides enhanced bearing surface area for load distribution across the workpiece surface.

Q: What is the benefit of the yellow zinc plating?
A: The yellow zinc plating with chromate conversion coating provides corrosion resistance through zinc sacrificial protection and a barrier layer against environmental exposure. The yellow iridescent finish allows for visual identification and assembly inspection.

Q: Are these nuts suitable for outdoor applications?
A: Yes, the yellow zinc plating provides corrosion resistance for outdoor and atmospheric exposure applications. The level of corrosion resistance is determined by coating thickness and chromate treatment specifications, with salt spray test performance defined by applicable coating standards.

Q: Do the serrations damage the workpiece surface?
A: The serrations on the flange underside create mechanical interference with the mating surface to provide locking action. This may produce marks on softer workpiece materials. For applications where surface marking must be minimized, use of a flat washer under the flange or alternative locking methods may be considered.

Q: Can these nuts be reused after removal?
A: Reusability depends on the serration design and application conditions. The serrations may experience wear or deformation during initial installation and removal, which can reduce locking performance in subsequent applications. For critical applications or multiple assembly cycles, locking performance should be verified through torque testing.

Q: What is the recommended tightening torque for thick flange nuts?
A: Tightening torque values are determined by the nut performance grade, thread size, material grade, and application load requirements. Torque specifications should be obtained from engineering standards or calculation methods defined in fastener design guidelines, considering friction conditions influenced by surface treatment and lubrication.

Installation Considerations

Torque application should follow specified tightening procedures. The serrated bearing surface engages the workpiece material upon initial contact, providing locking resistance. Over-tightening may deform the serration profile and reduce locking effectiveness, while under-tightening may not achieve full serration engagement. Thread condition affects torque-tension relationships; clean, dry threads without lubrication generally exhibit higher friction than lubricated threads. For yellow zinc plated nuts, coating thickness should be within specified tolerances to maintain thread fit and flange contact geometry. Inspection of flange underside condition is recommended before installation, as contamination or damage to the serrated surface may reduce clamping and locking performance.