Countersunk Open-End Knurled Steel Blind Rivet Nuts

Technical Specifications — Countersunk Knurled Steel Rivet Nuts

Product Specification Overview

Metric Thread Specifications

Metric thread dimensions and tolerances should be specified according to applicable ISO standards, including ISO 261, ISO 724, and ISO 965.

The actual rivet nut body diameter, countersink dimensions, installation hole, and grip interval must be confirmed against the approved product drawing.

Unified Inch Thread Options for North American OEM Projects

JUXIN FASTENERS can review customer-specific Unified inch-thread requirements.

Unified thread specifications may reference ASME B1.1.

These inch-thread options are subject to engineering and production feasibility review and are not confirmed standard stock items.

Dimensional Drawing Verification

The existing technical information includes the following dimensional references:

The original dimensional reference does not clearly identify whether these values represent overall length, body length, or another dimension.

They must not be used as mounting hole diameters or manufacturing tolerances without confirmation from the technical drawing.

For final engineering selection, refer to the detailed product PDF and CAD documentation, including the previously referenced pages 93–94.

Countersink and Mounting Hole Requirements

The approved installation drawing should define:

1. Mounting hole diameter and tolerance

2. Countersink included angle

3. Countersink major diameter

4. Countersink depth

5. Panel thickness

6. Remaining panel material

7. Installed head height

8. Available backside clearance

9. Rivet nut body length

10. Installation stroke requirements

Countersink angle must be determined from the actual fastener geometry rather than assumed from metric or inch thread designation.

Installation Procedure

Step 1 — Verify the Fastener

Confirm thread size, body diameter, grip range, head geometry, and material.

Step 2 — Prepare the Mounting Hole

Drill or punch the mounting hole to the approved dimensions.

Step 3 — Prepare the Countersink

Machine or form the countersink according to the specified angle, diameter, and depth.

Step 4 — Inspect the Panel

Check hole quality, burrs, panel thickness, and countersink geometry.

Step 5 — Select the Setting Tool

Use a compatible manual, pneumatic, hydraulic, or automated blind rivet nut installation tool.

Step 6 — Install the Insert

Position the rivet nut in the prepared hole and maintain proper tool alignment.

Step 7 — Apply the Setting Stroke

The installation tool pulls the threaded mandrel, deforming the unthreaded body section behind the panel.

Step 8 — Inspect the Installation

Verify backside deformation, flange seating, thread integrity, and panel condition.

Step 9 — Validate Mechanical Performance

Where required, conduct spin-out torque, axial pull-out, push-out, and repeated assembly tests.

Engineering Performance Validation

For OEM qualification, the following tests may be considered:

• Spin-out torque resistance

• Axial pull-out resistance

• Push-out resistance

• Installation deformation

• Thread inspection

• Flange seating verification

• Panel damage assessment

• Coating thickness inspection

• Corrosion testing

• Repeated assembly performance

Acceptance criteria should be defined by the customer drawing, installation specification, or project qualification plan.

Surface Treatment Requirements

The specified finish is color zinc plating.

Where applicable, coating requirements may reference ASTM B633 or relevant ISO electroplating specifications.

The final purchasing specification should define coating thickness, passivation type, corrosion requirements, and applicable restricted-substance compliance.

OEM Customization

JUXIN FASTENERS can review drawing-based requirements involving:

• Metric and Unified inch threads

• Customized body dimensions

• Alternative grip ranges

• Special countersunk head geometry

• Knurl configuration

• Surface treatment requirements

• Customer-specific inspection criteria

• Packaging and traceability requirements

Custom manufacturing feasibility, minimum order quantities, and lead times are confirmed during technical and commercial review.

RFQ Checklist

For an accurate OEM quotation, please provide:

• Technical drawing or CAD model

• Thread size and thread standard

• Panel material and thickness

• Installation hole dimensions

• Countersink angle and depth

• Required grip range

• Surface treatment specification

• Mechanical performance requirements

• Order quantity and annual forecast

• Inspection and documentation requirements

• Packaging and delivery requirements

Why Choose Knurled Countersunk Rivet Nuts?

Conventional smooth-body blind rivet nuts provide a practical solution for creating threads in thin materials.

 However, some applications require greater resistance to rotation when a mating screw is tightened or removed.

Knurled-body rivet nuts address this requirement through external ribs or serrations that engage with the surrounding mounting material during installation.

The effectiveness of this anti-rotation feature depends on panel material, hole tolerance, knurl geometry, installation deformation, and applied torque.

Improved Spin-Out Resistance

The external knurling increases mechanical engagement between the rivet nut and the installation hole.

This can improve resistance to rotation compared with a smooth-body design under suitable installation conditions.

For applications involving repeated maintenance or higher tightening torque, spin-out resistance should be verified through testing.

Flush-Mount Countersunk Head

The countersunk flange allows the installed rivet nut to sit within a prepared recess.

This reduces head protrusion and can improve clearance between mating components.

Typical applications include close-fitting covers, equipment panels, removable brackets, and fabricated assemblies where a raised flange is undesirable.

Single-Sided Installation

The rivet nut can be installed from the accessible side of a panel or hollow section.

No access to the rear of the workpiece is required during installation.

This is particularly useful for enclosed profiles, fabricated boxes, tubular components, and assembled equipment housings.

Open-End Threaded Design

The open-end construction allows the mating screw to extend through the rivet nut.

This provides flexibility when selecting screw engagement length, provided the assembly has adequate rear clearance.

The open-end design does not provide a sealed threaded cavity.

Reusable Mechanical Threads

The installed rivet nut provides an internal thread for removable mating components.

This supports equipment maintenance, replacement of access panels, and repeated mechanical assembly within the validated design limits.

Engineering Comparison: Knurled Versus Smooth Body

Knurled and smooth-body rivet nuts may have similar external dimensions but different installation behavior.

A smooth-body insert relies primarily on deformation and mechanical clamping to resist movement.

A knurled-body insert introduces additional surface engagement between the insert and the host material.

For OEM applications, the choice should consider:

• Required tightening torque

• Expected service cycles

• Panel material and hardness

• Installation hole tolerance

• Axial pull-out requirements

• Spin-out resistance

• Panel deformation

• Installation tooling and stroke

A knurled design does not automatically eliminate rotation under every loading condition.

The actual performance must be validated using the intended panel material and installation process.

Countersunk Head Versus Reduced Head

A full countersunk rivet nut is intended to sit within a matching countersunk mounting hole.

A reduced-head rivet nut uses a smaller flange that may provide a near-flush mounting interface without the same countersinking requirements.

These two configurations should not be treated as interchangeable.

A full countersunk design generally requires additional panel preparation and sufficient material thickness to support the countersunk head.

The required minimum panel thickness depends on the fastener geometry, countersink dimensions, and application loading.

For thin panels, engineers should confirm that the countersinking operation does not remove excessive supporting material.

Critical Engineering Considerations

1. Countersink Angle and Depth

The countersink angle must match the fastener head geometry.

An incorrect angle can prevent proper seating or concentrate loads at the flange.

Countersink depth must also be controlled to avoid excessive head protrusion or over-recessing.

2. Mounting Hole Diameter

The installation hole must be compatible with the rivet nut body.

An oversized hole may reduce retention and spin-out resistance.

An undersized hole can damage the insert or surrounding panel during installation.

3. Knurl Engagement

The effectiveness of the knurled body depends on how the serrations interact with the mounting material.

Softer materials may deform differently from high-strength steel panels.

Installation testing should verify that the knurling produces adequate retention without unacceptable panel damage.

4. Grip Range

The published product-series grip range is 0.5–5.0 mm.

Individual thread sizes and body lengths may have narrower grip intervals.

For countersunk installations, the remaining effective panel thickness must also be evaluated.

5. Installation Stroke

Insufficient setting stroke can result in inadequate backside deformation.

Excessive stroke may damage the internal thread, distort the panel, or compromise the rivet nut body.

Installation parameters should be established through controlled trials.

Color Zinc Surface Treatment

This product is supplied with a color zinc-plated finish.

Zinc plating provides sacrificial corrosion protection for the underlying steel in suitable service environments.

The color zinc finish may have a yellow or iridescent appearance depending on the passivation process.

For OEM purchasing programs, the coating specification should identify:

• Zinc coating thickness

• Passivation system

• Corrosion performance requirements

• Surface appearance criteria

• Restricted-substance requirements

• Applicable inspection methods

ASTM B633 and applicable ISO zinc electroplating standards may be referenced where specified by the customer.

Coating color alone does not establish RoHS or REACH compliance.

Industrial Applications

Automotive and Commercial Vehicles

Countersunk knurled rivet nuts can be considered for non-structural mounting brackets, interior panels, removable covers, and selected fabricated vehicle components.

The combination of flush installation and anti-rotation engagement can be beneficial in assemblies requiring periodic maintenance.

Electrical Enclosures and Control Cabinets

These threaded inserts provide fastening points for removable enclosure panels, internal equipment supports, and control cabinet components.

Where environmental sealing or electrical continuity is required, those functions must be separately engineered and validated.

Industrial Machinery

Potential applications include machine guards, equipment housings, access covers, and fabricated support components.

Railway Interior Equipment

Knurled countersunk inserts may be considered for non-structural interior panels, equipment covers, and selected mounting brackets.

Project-specific mechanical, vibration, and installation requirements must be evaluated.

HVAC and Appliance Manufacturing

Applications include removable access panels, sheet metal housings, and equipment support interfaces.

Metal Furniture and Industrial Fixtures

Flush-mount rivet nuts can provide reusable threads where appearance, clearance, and assembly efficiency are important.

OEM Fastener Engineering and Procurement

For design engineers, the most important considerations include countersink geometry, knurl engagement, mounting hole tolerance, panel thickness, and installed mechanical performance.

For purchasing managers and supplier development teams, the key requirements include material consistency, coating specifications,

 dimensional repeatability, production inspection, traceability, and reliable order fulfillment.

JUXIN FASTENERS supports drawing-based inquiries for customized blind rivet nuts and industrial fastening components.

Request an OEM Quotation

For countersunk knurled steel rivet nuts, custom blind threaded inserts, or industrial fastening requirements, please provide your technical drawing,

 thread size, panel thickness, mounting hole dimensions, surface treatment specification, and purchasing quantities.

JUXIN FASTENERS

Email: info@juxinfasteners.com

Website: www.juxinfasteners.com

Contact: https://www.juxinfasteners.com/contact-us/

Packaging and OEM Supply Requirements

Standard Export Packaging

JUXIN FASTENERS provides protective packaging for countersunk knurled steel blind rivet nuts intended for industrial distribution and OEM supply chains.

Standard packaging arrangements include plastic inner bags, reinforced outer cartons, and palletized shipments where required.

Packaging is selected to protect the threaded inserts and plated surfaces during storage, handling, and international transportation.

Reference Packaging Dimensions

These are previously supplied reference dimensions. Actual packaging dimensions and quantities are confirmed according to the product size, 

order quantity, and shipping requirements.

Customized OEM Packaging

Customer-specific packaging requirements may include:

• Customized packing quantities

• Customer part-number labels

• Barcode identification

• Batch and lot identification

• Moisture-resistant protection

• Special carton dimensions

• Pallet configuration

• Customer-specific shipping marks

Customized packaging may affect production costs and delivery lead times.

Packaging and Supply Chain Coordination

For OEM procurement programs, JUXIN FASTENERS can review customer requirements for part identification, batch traceability, 

packaging configuration, delivery schedules, and shipping documentation.

Final packaging specifications are agreed during order confirmation.

Request Packaging and Commercial Information

For bulk orders, customized rivet nuts, or customer-specific packaging requirements, contact:

JUXIN FASTENERS

Email: info@juxinfasteners.com

Website: www.juxinfasteners.com

Contact: https://www.juxinfasteners.com/contact-us/