Flat Head Closed-End Knurled Steel Blind Rivet Nuts

Technical Specifications — Closed-End Knurled Steel Blind Rivet Nuts

Product Identification

Metric Thread Sizes and US Inch Reference

These values represent standard ISO metric coarse thread dimensions and approximate inch conversions.

ISO metric threads are not interchangeable with UNC or UNF threads.

Applicable metric thread references may include ISO 261, ISO 724, and ISO 965, subject to the approved product drawing.

Imperial Thread Requirements — US OEM Applications

The supplied product information confirms metric sizes but does not establish available Unified inch thread configurations for this specific closed-end knurled design.

For US OEM projects, the following common Unified thread designations may be considered as inquiry references.

These sizes are not confirmed stock specifications or guaranteed available configurations.

Unified inch threads should be defined according to applicable ASME B1.1 requirements.

Grip Range — Metric and Imperial Reference

The published product-series grip range is 0.5–5.5 mm (approximately 0.020–0.217 in).

These are conversion references rather than approved grip ranges for individual part numbers.

Each selected configuration must be verified against its technical drawing.

Engineering Selection and Installation Guide

1. Knurled Body and Spin-Out Resistance

The knurled exterior incorporates surface features intended to engage the surrounding mounting material.

During installation, these features may provide additional resistance to insert rotation.

Performance depends on:

• Knurl profile and depth

• Mounting hole diameter

• Hole tolerance

• Panel material hardness

• Installation stroke or force

• Grip range

• Coating condition

• Applied tightening torque

A knurled body should not be considered a guarantee against spin-out without representative testing.

2. Closed-End Thread Depth and Screw Bottoming

The closed-end configuration has a finite internal cavity.

If the mating screw is too long, it may contact the closed end before the joint reaches its intended clamp load.

Potential consequences include:

• Incomplete joint clamping

• Misleading tightening torque readings

• Internal thread damage

• Deformation of the closed barrel

• Reduced assembly reliability

Engineers should verify usable internal thread depth after installation, mating screw penetration, and appropriate bottoming clearance.

The approved installed geometry should be used rather than the uninstalled body length alone.

3. Combined Anti-Rotation and Screw Bottoming Risk

Closed-end knurled rivet nuts introduce an important interaction between rotational retention and screw engagement.

If a mating screw bottoms against the closed barrel, continued tightening can transfer unintended loads into the installed insert.

Depending on the joint configuration, this may contribute to thread damage, barrel deformation, or insert rotation.

Therefore, a high spin-out torque value alone does not guarantee correct assembly.

OEM validation should consider both:

• Rotational retention of the installed insert

• Correct screw engagement and bottoming clearance

These checks should be performed together under representative installation conditions.

4. Mounting Hole Diameter and Knurl Engagement

The mounting hole must match the approved knurled-body geometry.

An oversized hole may reduce engagement between the knurled surface and mounting material.

An undersized hole may damage the coating, prevent proper insertion, or create excessive local deformation.

Engineers should verify:

• Nominal hole diameter

• Hole tolerance

• Hole roundness

• Burr condition

• Panel thickness

• Panel material hardness

• Knurl outer diameter

Do not determine mounting hole size directly from the nominal thread diameter.

5. Closed-End Sealing Limitations

The enclosed barrel eliminates the direct through-opening at the end of the threaded insert.

However, the installed assembly may still permit leakage around the flange-to-panel interface.

Closed-end rivet nuts should not automatically be described as watertight, airtight, or pressure-tight.

For applications requiring environmental sealing, evaluate:

• Flange seating

• Panel flatness

• Mounting hole condition

• Coating integrity

• Additional sealing elements

• Complete assembly leakage performance

Where applicable, enclosure ingress protection may be evaluated using IEC 60529.

6. Grip Range and Panel Thickness

The published product-series grip range is 0.5–5.5 mm (approximately 0.020–0.217 in).

Individual configurations may cover narrower ranges.

For multilayer assemblies, verify the combined installation thickness and intended clamping configuration.

The selected rivet nut must be matched to the actual panel thickness and approved grip range.

7. Pull-Out Resistance and Panel Deformation

Pull-out resistance depends on the installed backside deformation, mounting hole geometry, panel material, and rivet nut dimensions.

The flat head provides a bearing surface on the accessible side of the panel.

For thin or soft materials, evaluate local bearing deformation and possible pull-through.

Mechanical strength should be confirmed through representative testing rather than assumed from the steel material alone.

8. Installation Procedure

1. Confirm the rivet nut configuration and approved drawing.

2. Prepare the specified mounting hole.

3. Remove burrs and inspect the panel surface.

4. Select the correct installation mandrel.

5. Insert the knurled body into the mounting hole.

6. Seat the flange against the panel.

7. Keep the setting tool perpendicular to the panel.

8. Apply the approved installation stroke or force.

9. Inspect the formed backside retention section.

10. Verify thread integrity and rotational retention.

11. Confirm mating screw engagement without bottoming.

Manual or pneumatic setting equipment may be used when compatible with the selected product and approved installation process.

9. Blue Zinc Plating and Corrosion Requirements

The specified surface treatment is blue zinc plating.

For OEM purchasing, coating requirements should define:

• Zinc coating thickness

• Passivation chemistry

• Additional sealing or topcoat requirements

• Corrosion test method

• Environmental exposure conditions

• Applicable restricted-substance requirements

ASTM B633 and ISO 2081 may be referenced where technically applicable.

Blue zinc appearance alone does not establish corrosion resistance or regulatory conformity.

10. Galvanic Compatibility

When zinc-plated steel rivet nuts are installed in aluminum or other dissimilar metal panels, the complete assembly should be evaluated for galvanic corrosion risk.

Potential concerns include moisture exposure, coating damage, exposed mounting hole edges, and long-term environmental conditions.

Protective coatings, isolation measures, or alternative materials may be required.

11. OEM Validation and Inspection

Representative production validation may include:

• Mounting hole inspection

• Knurl geometry inspection

• Installation stroke or force verification

• Backside deformation inspection

• Flange seating

• Thread integrity

• Spin-out torque

• Axial pull-out resistance

• Screw bottoming clearance

• Repeated screw assembly

• Panel deformation

• Coating condition

• Corrosion testing where specified

• Assembly sealing tests where required

Acceptance criteria should be established according to the OEM application and approved technical documentation.

Technical Drawings and CAD

The existing product information references detailed specification PDF pages 91–92 and related CAD documentation.

Please confirm the applicable drawing revision before finalizing mounting hole size, knurl geometry, flange dimensions, 

body length, usable internal thread depth, or individual grip range.

OEM Technical RFQ Checklist

For accurate quotation and engineering review, please provide:

• Required metric or Unified inch thread size

• Panel material and thickness, in mm or inches

• Mounting hole diameter and tolerance

• Required grip range

• Flange dimensions

• Knurl geometry requirements, if specified

• Mating screw length and tightening torque

• Usable internal thread depth requirements

• Spin-out and pull-out performance requirements

• Environmental sealing requirements, if applicable

• Blue zinc coating specification

• Corrosion resistance requirements

• Approved drawing or CAD model

• Inspection and documentation requirements

• Sample quantity

• Initial order quantity and annual demand forecast

JUXIN FASTENERS supports drawing-based sourcing inquiries for standard and custom industrial blind rivet nut requirements.

How Closed-End Knurled Rivet Nuts Work

A closed-end knurled rivet nut is inserted into a prepared mounting hole and installed using a compatible blind rivet nut setting tool.

The installation process deforms the designated section of the insert body behind the panel, creating a mechanical retention feature.

The knurled exterior may engage the surrounding panel material to provide additional resistance to rotation.

The closed-end barrel prevents the mating screw from passing completely through the insert.

Unlike an open-end rivet nut, this configuration requires careful control of usable internal thread depth and screw penetration.

Engineering Advantages

Improved Rotational Retention Potential

The knurled exterior provides surface features that may increase mechanical engagement with the mounting material.

This can be beneficial in assemblies involving repeated screw tightening, maintenance access, or vibration exposure.

Actual spin-out resistance must be validated for the selected mounting material and installation conditions.

Enclosed Threaded Barrel

The closed end eliminates the direct opening through the insert barrel.

This can help protect the threaded cavity from direct exposure through the rear of the insert.

However, the installed assembly is not automatically watertight or airtight. Leakage may still occur around the flange-to-panel interface.

One-Sided Installation

The rivet nut can be installed from the accessible side of the mounting material.

This is useful in hollow profiles, closed equipment housings, and fabricated sheet metal structures.

Reusable Internal Threads

The insert provides an internally threaded fastening point for mating screws.

Repeated assembly performance depends on the thread design, applied tightening torque, and installed retention characteristics.

Typical Industrial Applications

Automotive and Transportation Equipment

Potential applications include non-critical mounting brackets, equipment covers, fabricated housings, and interior assembly components.

For vibration-exposed joints, engineers should validate rotational retention, axial pull-out resistance, and complete joint performance.

Electrical Enclosures and Control Cabinets

Closed-end knurled rivet nuts can provide threaded attachment points for access covers, mounting brackets, and internal equipment.

The enclosed barrel may be beneficial where designers want to avoid an open passage through the threaded insert.

Electrical safety, grounding, and environmental sealing must be evaluated at assembly level.

HVAC and Refrigeration Systems

These inserts may be considered for fabricated equipment housings, access panels, brackets, and sheet metal components.

For condensation-prone environments, coating requirements and assembly sealing must be specified separately.

Industrial Machinery and Equipment Housings

Applications may include removable machine covers, guards, mounting brackets, and fabricated steel enclosures.

The knurled body can be useful where repeated maintenance may create rotational loading on the installed insert.

Rail Vehicle Interior Equipment

Closed-end knurled steel rivet nuts may be considered for selected non-structural interior panels and equipment attachments, subject to project-specific engineering approval.

Mechanical retention, vibration, material, and documentation requirements should be defined by the applicable project specification.

Marine and General Fabrication

The closed-end configuration may be considered where an enclosed threaded cavity is desirable.

However, standard blue zinc-plated steel should not automatically be considered suitable for continuous marine exposure or aggressive corrosive environments.

Material and coating selection must be based on actual service conditions.

Closed-End Knurled Versus Open-End Knurled Rivet Nuts

The closed-end design is suitable where an enclosed threaded cavity is required.

The open-end design may be preferable where the mating screw must extend beyond the threaded barrel and sufficient backside clearance exists.

Both designs can incorporate knurled exterior geometry.

Selection should consider:

• Available screw engagement depth

• Backside clearance

• Environmental exposure

• Rotational retention requirements

• Mounting hole geometry

• Panel material and thickness

• Installation equipment compatibility

OEM Engineering and Procurement Support

JUXIN FASTENERS supports drawing-based sourcing and industrial purchasing requirements for closed-end knurled steel blind rivet nuts.

Engineering teams can submit mounting hole dimensions, panel thickness, screw engagement requirements, and mechanical retention criteria.

Purchasing managers and supplier development teams can provide approved drawings, coating specifications, 

inspection requirements, initial order quantities, and annual demand forecasts.

Request an OEM Quotation

For closed-end knurled steel blind rivet nuts and custom industrial threaded inserts, contact:

JUXIN FASTENERS

Email: info@juxinfasteners.com

Website: www.juxinfasteners.com

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

Please send your technical drawing, specifications, quantities, and purchasing requirements for review and quotation.

Packaging & OEM Ordering — Closed-End Knurled Steel Blind Rivet Nuts

Standard Export Packaging

JUXIN FASTENERS provides industrial export packaging for closed-end knurled steel blind rivet nuts to support product protection, handling, storage, and international transportation.

The standard packaging arrangement includes protective inner plastic bags, outer cartons, and palletized shipment where required.

Reference Packaging Dimensions

These are reference packaging dimensions. Actual carton quantities, dimensions, and pallet arrangements are confirmed according to product size and purchase order requirements.

Product Protection and Identification

Packaging arrangements may include:

• Protective plastic inner bags

• Reinforced export cartons

• Moisture-resistant protection where required

• Product identification labels

• Part number and specification marking

• Batch identification

• Quantity labels

• Palletized shipment where required

Packaging and identification requirements should be agreed before order confirmation.

Customized OEM Packaging

Customer-specific packaging options can be reviewed, including:

• Private labeling

• Customized barcode labels

• Customer part-number identification

• Specified carton dimensions

• Customer-defined packing quantities

• Special pallet configurations

• Customer-specific marking and traceability requirements

Customized packaging may involve additional costs or lead times depending on the agreed requirements.

OEM and Industrial Bulk Purchasing

JUXIN FASTENERS supports purchasing inquiries from OEM manufacturers, strategic sourcing teams, supplier development professionals, and industrial equipment manufacturers.

For quotation review, please provide:

• Required thread size and product configuration

• Approved technical drawing and revision

• Material and blue zinc coating requirements

• Panel thickness and grip range

• Installation and mechanical performance requirements

• Screw engagement and bottoming clearance requirements

• Inspection and documentation requirements

• Packaging and labeling specifications

• Initial order quantity

• Annual demand forecast

• Requested delivery schedule

Sample availability, minimum order quantity, pricing, production lead time, and ordering conditions are confirmed during quotation review.

Request an OEM Quotation

For closed-end knurled steel blind rivet nuts, custom threaded inserts, and industrial bulk purchasing requirements, contact:

JUXIN FASTENERS

Email: info@juxinfasteners.com

Website: www.juxinfasteners.com

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

Please send your technical drawing, specifications, and purchasing requirements for review and quotation.