Extended-Collar Hex Flange Nuts for Automotive OEM Assemblies

Extended-Collar Hex Flange Nuts for Automotive OEM Assemblies

Custom Hexagon Flange Nuts with Raised Threaded Bosses for Automotive Driveline, Gearbox and Industrial Machinery Applications

Juxin Fasteners manufactures extended-collar hex flange nuts for automotive OEMs, 

Tier-1 and Tier-2 suppliers, industrial machinery manufacturers and equipment builders requiring custom threaded fastening components with a raised cylindrical collar and integrated flange.

The featured product combines three distinctive geometric features:

• A six-point external hexagonal wrenching section.

• A wide, integrated circular flange.

• An extended cylindrical internally threaded collar projecting above the hexagonal body.

This configuration is also described using engineering terms such as raised threaded boss, extended threaded neck or custom collared hex flange nut.

The raised collar is the principal feature distinguishing this product from a conventional hex flange nut. 

Depending on the customer-approved drawing, it may provide additional available thread length, a raised fastening interface or clearance from adjacent components.

Juxin Fasteners supports made-to-drawing manufacturing, material selection, cold forming, CNC machining, product-specific secondary processing and industrial batch production.

Product Technical Specifications

All dimensions, mechanical properties and product functions must be verified against the approved engineering drawing.

What Is an Extended-Collar Hex Flange Nut?

An extended-collar hex flange nut is an internally threaded fastener combining a hexagonal wrenching body, an integral flange and a raised cylindrical threaded section.

Unlike a conventional hex flange nut, the extended-collar design includes an additional cylindrical projection above the hexagonal wrenching section.

The raised collar can be designed for a particular thread engagement length, mounting geometry or assembly clearance.

The actual functional purpose must be defined by the mating assembly.

Visible Structural Features

1. Six-Point Hexagonal Wrenching Section

The hexagonal section provides conventional wrench and socket engagement.

Important dimensions include width across flats, width across corners, hex height and corner radii.

2. Wide Circular Flange

The integrated flange provides a defined bearing interface.

Its outside diameter, thickness, flatness and contact geometry are controlled according to the drawing.

3. Raised Cylindrical Threaded Collar

The extended collar projects above the hexagonal section and contains a continuation of the internal thread.

Important parameters include collar outside diameter, collar height, wall thickness, thread length and concentricity.

4. Surface Finish

The featured product image has a yellow-iridescent metallic appearance.

The actual finish must be identified from the production specification. Appearance alone cannot confirm whether the coating is zinc with yellow passivation or another system.

Extended-Collar vs. Conventional Hex Flange Nuts

Extended Collar and Thread Engagement

A raised threaded collar can increase the available internal threaded length.

However, additional nut height does not automatically mean increased joint strength.

Effective thread engagement depends on:

• Mating bolt thread length.

• Thread pitch.

• Nut material.

• Bolt property class.

• Thread tolerance.

• Applied preload.

• Heat treatment.

• Joint geometry.

Engineers should verify thread stripping resistance and proof-load performance rather than assuming that a longer collar always produces a stronger joint.

Collar Height and Assembly Clearance

The raised collar may be designed to position the threaded interface relative to adjacent components.

Examples include assemblies where a recessed component, spacer or equipment bracket creates a specific access requirement.

The collar must not be assumed to provide centering, sealing or bearing support unless those functions are established by the drawing.

Flange Bearing Geometry

The integrated circular flange provides the interface between the nut and mating component.

Engineering considerations include:

• Flange outside diameter.

• Flange thickness.

• Bearing face flatness.

• Surface finish.

• Contact pressure.

• Perpendicularity to the thread axis.

• Concentricity of the collar and flange.

A wider flange may provide a larger bearing area, depending on the actual joint design.

It does not automatically prevent loosening under vibration.

Important Distinction: DIN 74361-2 Form A

DIN 74361-2 addresses fastening devices for stud-centred disc wheels used on motor vehicles and trailers.

Form A is associated with spherical-collar wheel nuts.

The spherical seating surface is an essential feature of that wheel fastening system.

The featured extended-collar hex flange nut should not be identified as DIN 74361-2 Form A without dimensional and seating-geometry verification.

Wheel Nut Seating Geometry

Wheel fastening systems may use spherical, conical or flat bearing interfaces.

These interfaces are not interchangeable.

Using an incorrect seating geometry can produce an unsafe wheel joint.

The featured product must not be recommended for wheel retention unless the complete wheel, stud, seating geometry and fastener specification have been approved.

Pinion Locking Nut vs. Extended-Collar Hex Flange Nut

A pinion locking nut is defined by its drivetrain retention function and approved locking or retention design.

Depending on the application, it may require:

• A specified bearing interface.

• Controlled bearing preload.

• Defined installation torque.

• Mechanical locking features.

• Axial retention performance.

• Vibration and fatigue verification.

• Reuse restrictions.

An extended-collar hex flange nut is not automatically a pinion locking nut.

Custom pinion retention designs can be evaluated separately when the customer supplies the assembly drawing and performance requirements.

Is an Extended-Collar Hex Flange Nut Self-Locking?

Not necessarily.

The hexagonal body, flange and extended collar do not inherently provide a prevailing-torque locking function.

Self-locking performance requires a separately defined mechanism, such as an approved all-metal thread deformation feature.

If locking performance is required, the drawing should specify the mechanism, installation requirements, prevailing-torque limits and reuse criteria.

Custom All-Metal Locking Options

Custom mechanical locking designs may be evaluated for suitable OEM projects.

Engineering considerations include:

• Locking geometry.

• Initial prevailing torque.

• Removal torque.

• Reuse performance.

• Mating bolt compatibility.

• Temperature exposure.

• Thread wear.

• Proof-load performance.

Locking performance must be verified through the applicable test procedure.

Material Options

Juxin Fasteners commonly works with the following customer-specified materials for this product family:

• 45# Carbon Steel.

• 30CrMnSi Alloy Steel.

• 40CrNiMoA Alloy Steel.

• 40Cr2MoV Alloy Steel.

• CH2132 Customer-Specified Material.

The material must be selected according to the approved drawing, mechanical requirements, heat treatment, manufacturing process and operating conditions.

45# Carbon Steel

45# carbon steel is a medium-carbon steel material used in industrial mechanical components.

It may be evaluated for custom flange nuts requiring defined mechanical properties and suitable heat treatment.

Relevant requirements include:

• Chemical composition.

• Material condition.

• Heat treatment.

• Hardness.

• Thread strength.

• Proof-load performance.

• Surface integrity.

Direct equivalence to SAE 1045 or EN C45 must be verified rather than assumed.

30CrMnSi Alloy Steel

30CrMnSi is a chromium-manganese-silicon alloy steel designation.

It may be evaluated for custom high-strength components where its material and heat treatment characteristics meet the application requirements.

The final mechanical properties must be verified.

40CrNiMoA Alloy Steel

40CrNiMoA is a chromium-nickel-molybdenum alloy steel designation.

It may be considered for custom components requiring controlled mechanical properties and heat treatment.

Material composition, hardness, thread strength and proof-load requirements must follow the approved specification.

40Cr2MoV Alloy Steel

40Cr2MoV is a chromium-molybdenum-vanadium alloy steel designation.

It may be evaluated for specialized mechanical applications.

High-temperature or fatigue suitability must be demonstrated through actual material data and engineering qualification.

CH2132 Customer-Specified Material

CH2132 is retained as the customer-provided material designation.

The full material specification, chemical composition, heat treatment and mechanical properties must be confirmed before production.

No ASTM, SAE or EN equivalent is assumed.

Material Selection Comparison

Nut Property Classes 8, 10 and 12

Metric steel nut property classes 8, 10 and 12 may be evaluated where applicable.

The finished nut must satisfy the governing mechanical property specification.

Relevant requirements include:

• Material composition.

• Heat treatment.

• Proof load.

• Hardness.

• Thread stripping resistance.

• Dimensional requirements.

• Inspection criteria.

The material grade alone does not establish the finished nut property class.

Metric Thread Sizes: M8–M36

Custom metric extended-collar hex flange nut designs can be evaluated across the M8–M36 engineering range.

These are standard coarse-pitch references, not confirmation of every size being stocked or previously manufactured.

Fine-pitch and special-thread designs may also be evaluated according to the approved drawing.

For example, M20×1.5 and M20×2.5 are different thread specifications and cannot be substituted.

American Inch-Thread Alternatives

For North American OEM programs, separate Unified inch-thread configurations may be evaluated.

These are potential custom thread references, not confirmed standard stock configurations.

Each design requires separate dimensional and manufacturing review.

Metric and Inch Threads Are Not Interchangeable

The comparisons are approximate diameter references only.

ISO metric, UNC, UNF, BSW and BSF threads must not be interchanged without engineering approval.

Surface Finish Options

Potential finishes include:

• Clear zinc plating.

• Blue-passivated zinc plating.

• Yellow zinc finish.

• Black zinc finish.

• Zinc-nickel alloy coating.

• Zinc-flake coating systems.

• Black oxide.

• Customer-specific protective coatings.

Finish selection depends on corrosion exposure, thread tolerance, coating thickness, friction requirements, operating temperature and mechanical properties.

The yellow-iridescent appearance of the featured product does not independently confirm the coating system.

Thread Tolerance and Coating Allowance

The approved drawing must define the thread tolerance before and after coating where applicable.

Metric internal thread tolerance classes such as 5H or 5G may be specified for particular custom designs.

The appropriate tolerance depends on the thread system, coating process, plating allowance and final functional thread requirements.

Thread surface roughness requirements should be stated using the correct units, such as Ra 3.2 µm where specified.

Application 1: Automotive Driveline Equipment

Custom extended-collar hex flange nuts may be evaluated for suitable automotive driveline equipment.

Potential applications include:

• Transmission equipment brackets.

• Driveline auxiliary assemblies.

• Mechanical mounting interfaces.

• Gearbox equipment supports.

• Custom vehicle equipment.

The collar geometry can be adapted to customer-specific mounting requirements.

Safety-critical driveline retention requires separate qualification.

Application 2: Automotive Gearbox Assemblies

Gearbox manufacturers may require custom fastening geometries where the threaded interface must be raised above the surrounding mounting surface.

Engineering considerations include:

• Collar height.

• Thread engagement.

• Bearing face geometry.

• Installation access.

• Joint preload.

• Vibration exposure.

Application 3: Automotive Powertrain Equipment

Suitable custom designs may be evaluated for:

• Powertrain auxiliary brackets.

• Mechanical support components.

• Equipment mounting interfaces.

• Custom drivetrain accessories.

Each application requires drawing and mechanical performance verification.

Application 4: Commercial Vehicle Equipment

Commercial vehicle OEMs may require custom high-strength flange nuts for selected mechanical equipment and brackets.

Potential applications include:

• Auxiliary equipment supports.

• Serviceable mechanical brackets.

• Industrial vehicle accessories.

• Custom mounting assemblies.

Wheel retention applications require separate wheel-specific engineering qualification.

Application 5: Industrial Gearboxes

Industrial gearbox manufacturers may require a raised threaded interface or specific flange geometry.

Potential applications include:

• Gearbox mounting assemblies.

• Mechanical drive equipment.

• Serviceable machinery components.

• Auxiliary equipment supports.

Application 6: Motors and Pumps

Extended-collar hex flange nuts may be evaluated for suitable:

• Industrial motor mounting brackets.

• Pump equipment supports.

• Mechanical housings.

• Drive equipment accessories.

The actual collar function and load requirements must be defined by the assembly.

Application 7: Valve Equipment

Custom flange nuts may be considered for selected valve equipment mounting assemblies.

Pressure-containing joints require the applicable design codes, material specifications and mechanical qualification.

Application 8: Heavy Machinery

Potential applications include:

• Industrial machinery mounting.

• Construction equipment brackets.

• Mining machinery accessories.

• Mechanical drive assemblies.

• Precision industrial equipment.

Application 9: Agricultural Equipment

Agricultural machinery manufacturers may require custom fastening geometries for protected mechanical equipment and brackets.

Material and coating selection should reflect vibration, moisture and outdoor exposure.

Application 10: Power Generation Equipment

Potential applications include:

• Generator equipment supports.

• Auxiliary mechanical assemblies.

• Industrial drive equipment.

• Power equipment mounting brackets.

Application 11: Wind Power Equipment

Selected custom flange nut designs may be evaluated for suitable auxiliary wind power machinery.

Fatigue, corrosion, preload and maintenance requirements must be assessed.

Application 12: Rail Equipment

Custom designs may be evaluated for selected rail equipment brackets and non-critical machinery assemblies.

Applicable rail specifications and project qualification requirements must be defined.

Application 13: Marine Machinery

Marine machinery manufacturers may require corrosion-resistant custom fastening components.

Material and coating selection must be matched to the actual service environment.

Application 14: Industrial Robotics and Automation

Potential applications include:

• Mechanical drive supports.

• Actuator mounting brackets.

• Custom machine assemblies.

• Precision equipment mounting.

Collar dimensions, tool access and assembly clearance must be reviewed.

Manufacturing Capabilities

Juxin Fasteners is an industrial fastener manufacturer supporting custom-engineered fastening components.

Our manufacturing capabilities include:

• Cold heading.

• Cold forming.

• CNC machining.

• Internal threading.

• Precision metal component manufacturing.

• Product-specific secondary operations.

• Heat treatment according to project requirements.

• Surface finishing.

• Dimensional inspection.

• Industrial batch manufacturing.

The actual manufacturing route depends on size, material, geometry, tolerance, mechanical properties and production volume.

OEM Manufacturing Workflow

A typical custom project may include:

1. Customer drawing review.

2. Thread specification confirmation.

3. Material grade assessment.

4. Mechanical requirement review.

5. Hexagonal wrenching geometry review.

6. Flange geometry review.

7. Collar height and diameter review.

8. Manufacturing feasibility assessment.

9. Selected forming or machining process.

10. Internal thread production.

11. Heat treatment where specified.

12. Dimensional and mechanical inspection.

13. Surface finishing.

14. Final quality inspection.

15. OEM packaging and batch delivery.

Quality Control and Inspection

A project-specific inspection plan may include:

• Material verification.

• Thread gauge inspection.

• Width across flats.

• Overall nut height.

• Collar height.

• Collar outside diameter.

• Flange outside diameter.

• Flange thickness.

• Bearing face flatness.

• Concentricity.

• Perpendicularity.

• Hardness testing.

• Proof-load testing.

• Locking performance testing where applicable.

• Magnetic particle inspection where specified.

• Fluorescent penetrant inspection where specified.

• Coating thickness inspection.

• Visual inspection.

• Packaging verification.

Inspection methods, sample quantities and acceptance criteria must follow the approved quality plan.

Engineering Standards and Technical References

ISO 261 / ISO 724

ISO metric thread designations and basic dimensions.

ISO 965 Series

ISO metric screw-thread tolerances.

ISO 898-2

Mechanical properties of specified carbon steel and alloy steel nuts within the standard's applicable scope.

ASME B1.1

Unified inch screw-thread requirements.

ISO 4042

Electroplated coating systems for fasteners.

DIN 74361-2

Fastening devices for stud-centred vehicle disc wheels. It is not a general specification for all extended-collar flange nuts.

Customer Engineering Drawings

The controlling documents for custom geometry, material, thread tolerance, mechanical performance, coating, inspection and acceptance requirements.

Standards references do not independently establish certification or conformity.

Information for Design Engineers

Please specify:

• Thread size and tolerance.

• Collar outside diameter.

• Collar height.

• Nut overall height.

• Width across flats.

• Flange outside diameter.

• Flange thickness.

• Bearing face geometry.

• Material grade.

• Mechanical properties.

• Required joint preload.

• Locking function where applicable.

• Operating temperature.

• Corrosion requirements.

Information for Manufacturing Engineers

Manufacturing engineers should evaluate:

• Socket and wrench compatibility.

• Assembly clearance.

• Collar interference.

• Thread engagement.

• Tightening procedure.

• Coating influence.

• Heat treatment consistency.

• Assembly repeatability.

Information for Production Managers

Production managers should consider:

• Assembly efficiency.

• Tool accessibility.

• Production repeatability.

• Batch consistency.

• Inspection requirements.

• Production scheduling.

• Rework prevention.

• Total manufacturing cost.

Information for Procurement and Supply Chain Managers

Procurement teams should establish:

• Approved 2D drawing or 3D CAD model.

• Material specification.

• Required nut property class.

• Thread designation and tolerance.

• Heat treatment requirements.

• Surface finish.

• Mechanical testing requirements.

• Locking performance requirements where applicable.

• Initial order quantity.

• Annual purchasing forecast.

• Packaging requirements.

• Drawing revision control.

• Delivery requirements.

Frequently Asked Questions

What is an extended-collar hex flange nut?

It is an internally threaded hexagonal flange nut with a raised cylindrical threaded collar extending above the hexagonal body.

What is the main difference from a standard hex flange nut?

The raised threaded collar provides an additional geometric feature for custom thread engagement or assembly requirements.

Is the raised collar the same as a spherical wheel seat?

No. A raised threaded collar and a spherical wheel seating surface are different geometric features.

Does this product conform to DIN 74361-2 Form A?

Conformity cannot be established from appearance alone. DIN 74361-2 Form A requires specific wheel nut geometry and technical requirements.

Is this product a pinion locking nut?

Only if the approved design defines the required pinion retention function and locking performance.

Are all extended-collar hex flange nuts self-locking?

No. A separate locking mechanism is required.

Can the collar provide more thread engagement?

It can increase available internal threaded length, but effective engagement depends on the mating bolt and complete joint design.

What materials are commonly used?

45# Carbon Steel, 30CrMnSi, 40CrNiMoA, 40Cr2MoV and CH2132 customer-specified material.

Can property classes 8, 10 and 12 be evaluated?

Yes, subject to the applicable specification, material, heat treatment, geometry and mechanical qualification.

What metric sizes can be reviewed?

Custom M8–M36 designs can be evaluated, subject to manufacturing feasibility.

Are inch-thread versions possible?

Custom UNC and UNF configurations can be evaluated according to approved drawings.

Are metric and inch threads interchangeable?

No. ISO metric, UNC, UNF, BSW and BSF are different thread systems.

Can these nuts be used in automotive manufacturing?

Suitable custom designs may be evaluated for automotive mechanical equipment and mounting assemblies. 

Safety-critical applications require separate qualification.

Does Juxin Fasteners support OEM batch manufacturing?

Yes. We support engineering drawing review, made-to-drawing manufacturing, dimensional inspection and industrial batch production.

Request a Quote — Extended-Collar Hex Flange Nuts

Juxin Fasteners manufactures industrial fasteners and custom precision metal components for automotive OEMs, 

Tier-1 and Tier-2 suppliers, mechanical engineers, manufacturing engineers, production managers, procurement specialists and supply chain managers.

We support custom extended-collar hex flange nuts for automotive driveline equipment, industrial gearboxes, motors, 

pumps, heavy machinery, power generation equipment and specialized OEM assemblies.

Recommended RFQ Information

• 2D engineering drawing or 3D CAD model.

• Metric or Unified inch-thread designation.

• Thread pitch and tolerance.

• Material grade.

• Required mechanical properties.

• Heat treatment specification.

• Width across flats.

• Overall nut height.

• Flange outside diameter.

• Flange thickness.

• Collar outside diameter.

• Collar height.

• Bearing face geometry.

• Locking mechanism, if required.

• Proof-load requirements.

• Surface finish and coating specification.

• Corrosion and temperature requirements.

• Dimensional inspection requirements.

• Mechanical testing requirements.

• Initial order quantity.

• Annual purchasing forecast.

• Packaging and delivery requirements.

Please send your engineering drawings and purchasing specifications for technical review and manufacturing quotation.

Juxin Fasteners

Industrial Fastener Manufacturer | Extended-Collar Hex Flange Nuts | Automotive OEM Fasteners | Custom Precision Metal Components

Website: https://www.juxinfasteners.com/

Email: info@juxinfasteners.com

Packaging Standard

At Juxin Fasteners, we apply standardized export packaging to ensure product protection, traceability, and compliance with international logistics requirements.

1. Standard Export Packaging

Unless otherwise specified, all products will be packed according to our factory standard export packaging, which includes:

Moisture-resistant inner protection

Poly bag or small box packing as required

Reinforced export cartons

Clear labeling with part number, specification, batch number, and quantity

Palletizing for sea or air shipment when necessary

Our standard packaging is designed to ensure safe transportation, efficient warehousing, and long-distance international shipping.

2. Customized Packaging Options

We also provide customized packaging solutions according to customer requirements, including but not limited to:

Private labeling

Customized barcodes

Specific carton dimensions

Retail packaging

Special pallet configuration

Customer-specific marking and identification

So that you know, customized packaging may involve additional costs and extended lead time depending on the complexity of the requirements.

3. Compliance & Quality Assurance

All packaging processes are controlled under our ISO 9001 quality management system to ensure consistency, traceability, and product integrity throughout the supply chain.