Closed End Sealing Blind Rivet Nuts for EV Battery Enclosures | Waterproof Threaded Inserts

Closed-End Sealing Blind Rivet Nuts

Waterproof Threaded Fastening Solution for EV Battery Enclosures

Closed-End Sealing Blind Rivet Nuts are specialized threaded inserts designed to provide high-strength fastening and reliable sealing in thin-sheet metal assemblies. They are widely used in automotive, aerospace, electronic equipment, and industrial enclosures where threaded connections must be created in materials that are too thin for tapping.

Blind rivet nuts are often described as the ideal fastening solution for thin sheet connections, particularly when installation access is available from only one side of the component. These fasteners enable the formation of strong, reusable internal threads in sheet metal thicknesses ranging from 0.5 mm to 13 mm, making them highly suitable for modern lightweight structures.

In electric vehicle (EV) battery enclosure systems, closed-end sealing rivet nuts are increasingly used to create sealed fastening points that prevent water, dust, and contaminants from entering the battery housing, ensuring the safety and reliability of the entire battery system.

Design Features of Closed-End Sealing Rivet Nuts

Closed-end sealing rivet nuts combine structural fastening performance with environmental sealing technology.

Closed-End Structure

Unlike standard open rivet nuts, closed-end rivet nuts feature a sealed barrel design that prevents liquids or dust from passing through the threaded insert.

This structure is essential for sealed housings and electrical enclosures, particularly in EV battery systems, where moisture intrusion can lead to serious safety risks.

Integrated Seal Ring Technology

A captured sealing ring integrated under the flange ensures reliable sealing between the rivet nut and the installation surface.

Seal ring technology offers several advantages:

• consistent sealing performance

• reliable installation even in automated production lines

• protection against external environmental influences

The sealing ring compresses during installation, forming a durable seal that maintains metal-to-metal structural contact while preventing fluid penetration.

Robust Mechanical Locking

During installation, the rivet nut collapses behind the sheet metal to form a backside flange, securely clamping the material between the flange and the deformed body.

This provides:

• strong pull-out resistance

• high vibration resistance

• reliable structural fastening

Material Options

Closed-end sealing blind rivet nuts are available in multiple materials to meet automotive and industrial performance requirements.

Stainless Steel Rivet Nuts

Common stainless steel grades include:

• 304 (18-8) stainless steel

• 316 stainless steel

• 316L stainless steel

Advantages include:

• excellent corrosion resistance

• resistance to moisture and chemicals

• long-term performance in outdoor and wet environments

Stainless steel rivet nuts are widely used in EV battery enclosures and electronic housings.

Carbon Steel Rivet Nuts

Carbon steel rivet nuts provide:

• high mechanical strength

• excellent load-bearing capacity

• cost-effective large-scale production

They are typically treated with zinc plating or other corrosion-resistant coatings, making them suitable for automotive structural assemblies.

Thin Sheet Metal Fastening Advantages

Closed-end sealing rivet nuts solve several problems associated with thin sheet metal fastening.

Ideal for Thin Plates

Traditional tapping is difficult in thin materials. Rivet nuts create strong, reusable threads in sheet metals ranging from 0.5 mm to 13 mm thickness.

Single-Side Installation

Blind rivet nuts can be installed from one side of the workpiece, making them ideal for closed structures such as tubes, battery housings, and equipment enclosures.

Customizable Design

Different body shapes, hole depths, and installation dimensions can be customized to meet specific design requirements.

Manufacturers can provide customized rivet nuts optimized for:

• different sheet thicknesses

• structural load requirements

• sealing performance targets

Installation Method

Closed-end sealing rivet nuts are typically installed using manual, pneumatic, or automated rivet nut tools.

Installation process:

1. Drill or punch a hole in the sheet material.

2. Insert the rivet nut into the hole.

3. Use a rivet nut tool to pull the threaded mandrel.

4. The rivet nut collapses and forms a secure backside flange.

5. The sealing ring compresses to form a waterproof sealing point.

This process creates a strong threaded connection and sealed installation point in a single operation.

Application in Electric Vehicle Battery Enclosures

The power battery system is the core energy component of electric vehicles, and its reliability directly affects vehicle safety and performance.

EV battery packs are typically installed under the vehicle chassis, where they are exposed to:

• road water and splash

• dust and debris

• vibration and temperature fluctuations

Therefore, battery enclosure systems must meet strict environmental protection requirements.

IP67 Sealing Requirements for EV Battery Packs

To ensure system safety, EV battery enclosures typically require IP67 protection levels, which include:

• complete protection against dust ingress

• resistance to temporary water immersion

Closed-end sealing rivet nuts help maintain this level of protection by preventing leakage paths at fastening points.

Leak Testing in EV Battery Systems

Battery packs and cells undergo rigorous leakage testing to verify sealing performance.

Typical tests include:

• air pressure leak tests

• enclosure sealing verification

• environmental durability testing

Closed end sealing rivet nuts used in automotive applications are pressure-tested during manufacturing, ensuring compliance with strict automotive quality standards and sealing requirements.

Key Applications in EV Battery Pack Structures

Battery Pack Enclosure Assembly

Sealing rivet nuts are used to secure:

• battery enclosure covers

• protective housings

• sealing flange structures

They provide threaded fastening points while maintaining enclosure sealing integrity.

Electrical Component Mounting

Inside battery enclosures, rivet nuts provide mounting points for:

• battery modules

• cooling systems

• sensors and controllers

Structural Mounting Interfaces

They are also used for fastening external brackets and protective structures connected to the battery enclosure frame.

Advantages for EV Manufacturing

Closed-end sealing blind rivet nuts provide several advantages for electric vehicle manufacturing:

• strong reusable threads in thin sheet materials

• blind installation capability

• waterproof and dustproof sealing performance

• compatibility with automated assembly lines

• compliance with automotive sealing standards

These advantages make them an essential fastening solution for modern EV battery systems and sealed electronic enclosures.