EV Battery Pack Assembly: Fastening and Joint Design Solutions

Electric vehicle battery pack assembly is not simply a process of joining a battery cover to a tray with bolts.

Modern EV battery systems integrate battery modules, lightweight aluminum structures, cooling components, 

battery management systems (BMS), power electronics, sealing interfaces, electrical insulation, and structural mounting points within a compact assembly.

These combinations create a fastening environment in which engineers must consider more than fastener diameter, thread size, or strength class.

The fastening system may need to account for:

• Different coefficients of thermal expansion between steel, aluminum, and polymer components

• Galvanic corrosion risk at dissimilar-metal interfaces

• Local bearing and pull-through strength of aluminum sheet

• Thread stripping and boss failure in polymer components

• Joint preload retention under vibration and thermal cycling

• Hole size and positional tolerance

• Sealing requirements around battery enclosure interfaces

• Electrical insulation where required

• Coating compatibility with aluminum and other mating materials

• Automated assembly and torque-control capability

• Serviceability and replacement requirements

• Manufacturing tolerances across large battery enclosure assemblies

For sealed battery packs, one engineering distinction is particularly important:

A fastener can contribute to an IP-rated battery enclosure design, but the fastener itself does not independently guarantee an IP67 rating.

Ingress-protection performance belongs to the completed enclosure system. Housing geometry, gaskets or seals, joint compression, fastener spacing, 

surface flatness, cable interfaces, vents, plugs, manufacturing variation, and the final assembly process can all influence sealing performance.

The completed assembly should therefore be validated against the applicable enclosure protection requirements.

JUXIN FASTENERS supports EV battery pack and automotive fastening projects involving high-strength bolts, locking fasteners, blind rivet nuts, 

weld fasteners, self-clinching fasteners, threaded inserts, polymer fastening components, and custom drawing-based parts.

This guide focuses on how these fastening technologies interact with battery pack assembly, joint engineering, manufacturing, and sourcing decisions.

Start With the Joint Function, Not the Fastener

Before selecting a fastener, engineers should first define what the connection must accomplish.

Different battery pack joints may need to provide:

• Structural clamping

• Permanent captive threads

• One-sided installation

• Reinforced threads in aluminum

• Threads in polymer components

• Controlled gasket compression

• Resistance to vibration-induced loosening

• Electrical isolation

• Component spacing

• Serviceable attachment

• Permanent sheet joining

• Alignment or location

These functions should not automatically use the same fastening technology.

A structural battery-frame bolt, for example, performs a fundamentally different function from a blind rivet nut installed in a thin enclosure wall.

Similarly, a fastener responsible for clamping should not automatically be expected to provide precise component location unless the joint has been designed for both functions.

A useful engineering sequence is:

Joint Function → Parent Material → Load → Access → Installation Process → Fastener Type → Preload or Setting Requirement → Environmental Conditions → Validation

This approach helps prevent fastener selection from becoming a late-stage hardware purchasing decision.

Understand the EV Battery Pack Assembly Architecture

A battery pack can contain several different mechanical assembly zones, and each zone can create a different fastening requirement.

Battery Modules and Internal Structures

Fasteners may be used for:

• Module frames

• Module supports

• Brackets

• Internal structural members

• Sensor mounting

• Electrical component mounting

Depending on the design, potential solutions include bolts, screws, threaded inserts, standoffs, spacers, and custom components.

Battery Tray and Structural Enclosure

The lower enclosure may contain:

• Aluminum extrusions

• Aluminum sheet

• Cast aluminum components

• Steel reinforcement

• Cross-members

• Mounting brackets

• Machined interfaces

Potential fastening technologies include:

• High-strength bolts

• Flange bolts

• Weld nuts

• Weld studs

• Blind rivet nuts

• Self-clinching fasteners

• Threaded inserts

• Blind rivets

• Custom fasteners

Battery Cover and Sealing Interface

The battery cover may require:

• Controlled clamp load

• Gasket compression

• Serviceability

• Fastener-spacing control

• Cover-flatness control

• Corrosion protection

The fastening strategy should therefore be developed together with the enclosure sealing strategy.

BMS, Sensors, and Electrical Assemblies

Battery management and electrical assemblies may use:

• Machine screws

• Small threaded fasteners

• Standoffs

• Spacers

• Threaded inserts

• Plastic or nylon fasteners

• PCB supports

• Cable-management components

These applications may prioritize electrical isolation, compact packaging, positioning, and serviceability rather than high structural clamp load.

Thermal Management Interfaces

Cooling plates, manifolds, brackets, sensors, and other thermal-management components may introduce additional requirements involving:

• Controlled clamping

• Flatness

• Thermal expansion

• Corrosion

• Coolant exposure

• Sealing

• Service access

Fastener selection should therefore follow the specific function of each assembly zone rather than applying one fastening specification throughout the complete battery pack.

How Parent Materials Change the Fastening Strategy

Modern battery pack structures can combine:

• Aluminum alloys

• Carbon steel

• Alloy steel

• Stainless steel

• Engineering polymers

• Elastomeric seals

• Composite materials

• Electrical insulation materials

• Thermal-interface materials

These materials should not be treated as mechanically equivalent.

Aluminum Structures

Aluminum can support lightweight and integrated enclosure designs, but engineers should evaluate:

• Local bearing strength

• Thread stripping

• Surface damage

• Galvanic interaction

• Thermal expansion

• Joint stiffness

• Coating compatibility

Simply replacing a steel component or fastener with aluminum does not automatically create a better lightweight joint.

The complete load path and joint architecture should be considered.

Engineering Polymers

Components manufactured from PA6, PA66, PPS, PC/ABS, and other engineering polymers may require consideration of:

• Polymer grade

• Reinforcement

• Moisture absorption

• Creep

• Temperature

• Chemical exposure

• Boss geometry

• Thread form

• Electrical insulation

• Flame-performance requirements where applicable

Polymer designations should not be treated as interchangeable.

Mixed-Material Joints

Where steel fasteners are used with aluminum or other materials, engineers may also need to consider:

• Electrical continuity

• Galvanic corrosion

• Surface coatings

• Isolation materials

• Water retention

• Drainage

• Differential thermal expansion

Material selection and fastener selection should therefore be coordinated rather than handled as separate decisions.

Threaded Connections in Polymer Battery Components

When screws are installed directly into polymer bosses, thread engagement should be determined according to the actual assembly rather than by applying a universal multiple of nominal screw diameter.

Relevant variables include:

• Polymer grade

• Glass-fiber or other reinforcement

• Screw geometry

• Boss diameter

• Boss wall thickness

• Installation torque

• Pull-out requirement

• Service temperature

• Thermal cycling

• Creep

• Repeated assembly

A useful engineering sequence is:

Thread Stripping Strength → Boss Strength → Pull-Out Resistance → Installation Torque → Assembly Variation → Thermal Cycling and Creep → Long-Term Joint Retention

Where repeated assembly or greater mechanical loading is required, a metal threaded insert may provide a more suitable interface than relying solely on molded polymer threads.

Potential solutions include:

• Brass threaded inserts

• Knurled brass inserts

• Heat-set inserts

• Ultrasonic inserts

• Press-fit inserts

• Self-tapping inserts

• Molded-in inserts

• Custom threaded bushings

Final insert selection should follow the parent material, boss design, installation method, and mechanical requirements.

Battery Cover Fastening and Gasket Compression

Fastener tightening across a large battery enclosure cover should be coordinated with the gasket and enclosure geometry.

The engineering objective is not simply:

“Tighten every bolt to the same torque.”

The objective is to achieve the required joint compression and preload distribution without causing unacceptable enclosure distortion or damaging the sealing system.

Depending on the design, engineers may evaluate:

• Target clamp load

• Gasket compression

• Cover flatness

• Flange stiffness

• Fastener spacing

• Bolt preload

• Friction

• Torque scatter

• Tightening tool capability

• Assembly sequence

• Leak-test results

A staged or cross-pattern tightening sequence may be appropriate for some multi-fastener cover designs, but no universal tightening percentage sequence should be applied to every battery enclosure.

The appropriate process should be established through joint testing and assembly validation.

ISO 16047 may be relevant when evaluating torque/clamp-force relationships for threaded fasteners.

High-Strength Bolts for Structural Battery Pack Joints

High-strength bolts can be used in structural battery pack joints where the engineering design requires the corresponding mechanical properties.

Potential applications may include:

• Battery structural frames

• Battery-to-vehicle mounting

• Enclosure reinforcement

• Cross-members

• Module-support structures

• Structural brackets

Property classes such as 8.8 or 10.9 may be specified for particular applications, but they should not be treated as universal EV battery requirements.

Fastener selection should consider:

• Required clamp load

• Tensile loading

• Shear loading

• Fatigue

• Joint stiffness

• Mating thread strength

• Grip length

• Surface treatment

• Friction condition

• Tightening method

• Corrosion environment

• Customer or OEM specification

A higher-strength bolt does not automatically create a stronger joint.

In an aluminum assembly, for example, local bearing, thread strength, or deformation of the parent material may become the limiting condition before the bolt reaches its mechanical capacity.

Captive Thread Solutions for Battery Pack Assembly

Battery enclosures frequently require captive threaded attachment points.

Several technologies can provide them, but they solve different manufacturing and assembly problems.

Weld Nuts

Projection weld nuts can provide permanent threaded attachment points in suitable weldable structures.

Selection should consider:

• Parent material

• Sheet thickness

• Projection geometry

• Weld process

• Electrode access

• Coating condition

• Torque resistance

• Final assembly requirement

Square weld nuts, hex weld nuts, flange weld nuts, and application-specific weld nut geometries may be evaluated according to the sheet-metal design and welding process.

Weld Studs

Weld studs can provide fixed threaded mounting points for brackets, electrical components, cable-management hardware, and other enclosure components.

The appropriate welding process depends on the stud design, substrate, load direction, and manufacturing requirements.

Self-Clinching Fasteners

Self-clinching nuts, studs, and standoffs can provide captive features in compatible sheet materials.

Selection should consider:

• Sheet material

• Sheet hardness

• Sheet thickness

• Hole geometry

• Edge distance

• Installation force

• Push-out requirement

• Torque resistance

Blind Rivet Nuts

Blind rivet nuts can create reusable internal threads where backside access is unavailable.

Selection should consider:

• Parent material

• Sheet thickness

• Grip range

• Hole diameter

• Hole shape

• Anti-rotation requirement

• Pull-out requirement

• Spin-out requirement

• Installation equipment

• Service requirements

Threaded Inserts

Threaded inserts may be used where aluminum, polymer, or other parent materials require reinforced threads.

The correct insert technology depends on the parent material, installation process, load requirement, and required service life.

Joining Methods for Aluminum Battery Pack Structures

Battery trays and enclosure structures may combine aluminum extrusions, sheet, castings, and steel reinforcement components.

Depending on material thickness, accessibility, structural requirements, production volume, and manufacturing process, joining methods may include:

No single joining technology is universally superior.

The appropriate process depends on joint function, material stack, production equipment, installation access, required serviceability, and validation requirements.

Blind Rivet Nuts for One-Sided Battery Enclosure Assembly

Blind rivet nuts can be particularly useful in aluminum battery enclosure structures where backside access is restricted.

Available solutions may include:

• Round-body rivet nuts

• Knurled-body rivet nuts

• Half-hexagonal rivet nuts

• Full-hexagonal rivet nuts

• Open-end designs

• Closed-end designs

• Reduced-head designs

• Flat-head designs

• Application-specific sealing configurations

Anti-rotation requirements deserve particular attention.

A round-body rivet nut, knurled design, half-hexagonal body, and full-hexagonal body do not provide identical behavior in every parent material.

Hole geometry, substrate strength, setting process, and installation torque all influence performance.

Sealing-related versions may incorporate:

• Elastomeric elements

• Under-head seals

• Sealing coatings

• Sealants

• Closed-end geometry

However, a sealing feature does not automatically guarantee IP67 performance.

A validated enclosure may require control of:

• Hole diameter

• Hole roundness

• Material thickness

• Grip range

• Rivet-nut setting

• Flange geometry

• Seal compression

• Gasket material

• Fastener spacing

• Cover flatness

• Tightening process

• Installation equipment

• Leak testing

• Thermal cycling

• Environmental exposure

The appropriate engineering statement is:

A sealed blind rivet nut can contribute to an IP-rated enclosure design when integrated into a validated sealing system.

It should not be treated as an independent guarantee of the final enclosure IP rating.

Sealing Is a Battery Enclosure System Requirement

Battery enclosures may require protection against:

• Water

• Dust

• Road spray

• Condensation

• Coolant

• Environmental contamination

Fasteners contribute to the sealing architecture through clamp load, spacing, retention, and local interface design.

But final sealing performance can also depend on:

Fastener Preload + Flange Stiffness + Gasket Geometry + Gasket Compression + Surface Flatness + Fastener Spacing + Cover Deformation + Temperature Cycling + Manufacturing Variation + Environmental Validation

This creates an important sourcing distinction.

A procurement specification should not simply request a “waterproof bolt” or “IP67 rivet nut” when the actual requirement belongs to the completed enclosure.

Engineering and procurement teams should instead define whether the application requires:

• Water resistance

• Splash resistance

• Leak prevention

• Dust protection

• An IP-rated enclosure

• Coolant containment

• Pressure control

• Chemical resistance

These are not interchangeable requirements.

Vibration, Preload, and Anti-Loosening Strategy

EV battery assemblies can experience vibration, cyclic loading, and thermal changes.

Fastener self-loosening and preload loss can be influenced by:

• Initial preload

• Transverse displacement

• Joint stiffness

• Friction

• Interface settlement

• Fastener geometry

• Thread geometry

• Temperature

• Repeated assembly

• Locking mechanism

The engineering process should therefore begin with the joint rather than with the locking device.

A useful sequence is:

Joint Load → Required Clamp Force → Fastener Selection → Joint Stiffness → Torque/Tension Relationship → Preload Variation → Vibration and Thermal Cycling → Locking Strategy → Validation

Potential locking technologies include:

All-Metal Prevailing-Torque Nuts

These can be considered where a metallic prevailing-torque mechanism is required.

Performance depends on nut design, material, coating, temperature, and installation history.

Nylon Insert Lock Nuts

Non-metallic insert lock nuts can provide prevailing torque in suitable applications.

Temperature, chemical exposure, polymer aging, and reuse requirements should be evaluated for the actual application.

Wedge-Locking Systems

Wedge-locking systems may be considered for joints where the design requires additional resistance to loosening caused by transverse movement.

Serrated Flange Systems

Serrated interfaces can provide rotational resistance but require careful evaluation on softer aluminum surfaces because local surface damage can affect contact conditions, coating integrity, and preload behavior.

ISO 2320 provides functional requirements and test methods for applicable prevailing-torque steel nuts.

A universal reuse count or temperature limit should not be assigned to every locking nut design without the corresponding product qualification and application specification.

Managing Galvanic Corrosion in Aluminum Battery Structures

Steel-to-aluminum interfaces require corrosion engineering when electrical contact and environmental exposure can create conditions for galvanic corrosion.

Risk depends on multiple variables, including:

• Alloy composition

• Surface condition

• Coating

• Electrolyte exposure

• Humidity

• Water retention

• Joint geometry

• Electrical continuity

• Cathode-to-anode area relationship

• Temperature

• Drainage

• Salt exposure

• Coating damage

A single voltage-difference threshold should therefore not be used as a universal rule for determining galvanic corrosion risk.

Material Pairing

Select material combinations compatible with the mechanical and environmental requirements.

Electrical Isolation

Where compatible with joint requirements, possible approaches can include:

• Polymer washers

• Insulating coatings

• Isolation films

• Non-conductive sealants

• Composite barriers

Protective Coatings

Depending on the specification, steel fasteners may use:

• Zinc plating

• Zinc-nickel plating

• Zinc-flake coating systems

• Organic topcoats

• Application-specific protective systems

Drainage and Interface Design

Even an appropriate coating system can perform poorly if the assembly traps water or electrolyte around the fastener.

Battery pack design should therefore consider drainage, seal continuity, crevice geometry, edge protection, and possible coating damage during installation.

Surface Treatment and Hydrogen-Embrittlement Risk

Surface treatment can influence:

• Corrosion resistance

• Friction

• Tightening behavior

• Dimensional fit

• Electrical interaction

• Appearance

Potential treatments can include:

• Zinc plating

• Zinc-nickel plating

• Zinc-flake systems

• Black oxide

• Nickel plating

• Passivation for suitable stainless steel components

• Organic topcoats

• PTFE-based coatings

• Customer-specified treatments

For high-strength steel fasteners, surface-treatment selection also requires consideration of hydrogen-embrittlement risk.

The engineering issue is not simply corrosion resistance.

It involves the interaction between:

Steel Strength + Heat Treatment + Surface Treatment + Hydrogen Exposure + Process Controls + Service Environment

ISO 4042 addresses electroplated coating systems for steel fasteners and includes requirements and recommendations related to hydrogen-embrittlement risk management.

ISO 10683 may be relevant for applicable zinc-flake coating systems.

The correct engineering objective is not to claim “zero hydrogen embrittlement.”

The objective is to control the manufacturing and coating processes and verify the finished fastener against the applicable specification.

Thermal Expansion in Mixed-Material Battery Joints

Battery pack assemblies may experience significant temperature variation during operation and environmental exposure.

Aluminum and steel have different coefficients of thermal expansion.

A simplified representation of differential free thermal expansion is:

ΔL = L(α₁ − α₂)ΔT

where:

• L = characteristic length

• α₁ = coefficient of thermal expansion of material 1

• α₂ = coefficient of thermal expansion of material 2

• ΔT = temperature change

However, this calculation does not directly provide the change in bolt preload in an assembled joint.

Actual joint response also depends on:

• Bolt stiffness

• Clamped-member stiffness

• Joint geometry

• Grip length

• Fastener diameter

• Material elasticity

• Contact conditions

• Thermal expansion of the individual components

• Structural constraints

This is why long or highly constrained aluminum-to-steel battery joints may require additional joint analysis rather than simply selecting a higher-strength bolt.

Thermal-cycle validation may need to evaluate:

• Initial preload

• Preload retention

• Seal compression

• Cover deformation

• Joint slip

• Fastener fatigue

• Corrosion

• Leakage

• Electrical isolation where required

Fastening Thermal Management and BMS Components

Not every fastener inside a battery pack is a structural enclosure fastener.

This distinction is important when developing a sourcing strategy.

Thermal Management Components

Cooling plates, cooling channels, manifolds, brackets, sensors, and other thermal-management components may use:

• Machine screws

• Flange bolts

• Locking nuts

• Threaded inserts

• Studs

• Custom fasteners

• CNC machined components

Selection may need to consider:

• Parent material

• Clamp-load requirement

• Flatness

• Thermal expansion

• Corrosion

• Coolant exposure

• Chemical compatibility

• Sealing

• Serviceability

Where a fastening joint interacts with a coolant or sealing interface, the fastener should be evaluated as part of the complete thermal-management assembly.

BMS and Electrical Components

BMS housings, sensors, electronic modules, and electrical support components may use:

• Small machine screws

• Threaded inserts

• Self-clinching standoffs

• Metal spacers

• Plastic spacers

• Nylon screws

• Nylon nuts

• Nylon washers

• PCB supports

• Cable clips

• Custom insulating components

Engineering considerations may include:

• Electrical isolation

• Component spacing

• Packaging

• Temperature

• Polymer creep

• Chemical compatibility

• Service access

• Cable routing

• Sensor positioning

Material and fastening technology should be selected according to the actual electrical and mechanical requirements.

EV Battery Pack Fastener Selection Matrix

The following matrix can help engineering and procurement teams narrow the initial fastening approach.

This matrix should be treated as an initial engineering filter rather than a universal product specification.

Common Battery Pack Fastening Failure Modes

Understanding how a joint can fail is often more useful than simply specifying a stronger fastener.

Preload Loss

Possible contributors include:

• Insufficient initial preload

• Embedment

• Surface settlement

• Thermal effects

• Joint slip

• Torque variation

• Incorrect friction assumptions

Thread Stripping

Possible contributors include:

• Insufficient engagement

• Weak parent material

• Polymer creep

• Excessive installation torque

• Incorrect thread specification

• Repeated assembly

Rivet Nut Spin-Out

Possible contributors include:

• Incorrect hole size

• Incorrect grip range

• Insufficient setting

• Unsuitable substrate

• Incorrect body geometry

• Installation variation

Galvanic Corrosion

Possible contributors include:

• Dissimilar-metal contact

• Moisture

• Coating damage

• Salt exposure

• Poor drainage

• Incompatible surface treatment

Seal Leakage

Possible contributors include:

• Incorrect gasket compression

• Cover distortion

• Surface-flatness variation

• Fastener-spacing problems

• Uneven preload

• Seal degradation

• Assembly variation

Fatigue Failure

Possible contributors include:

• Stress concentration

• Insufficient preload

• Joint slip

• Cyclic loading

• Geometry

• Surface condition

• Thread-root stresses

Failure analysis should consider the complete joint rather than attributing every failure to the fastener itself.

Designing Fasteners for Automated Battery Pack Assembly

Fastener selection should also consider how the component will be installed in production.

For automated or semi-automated assembly, engineering teams may need to evaluate:

• Fastener feeding

• Orientation

• Tool access

• Installation speed

• Torque control

• Angle monitoring where applicable

• Setting-force control

• Fastener presence detection

• Cross-threading risk

• Hole-position variation

• Assembly traceability

• Inspection capability

A fastener can meet mechanical requirements but still create production problems if its geometry or installation method is incompatible with the assembly equipment.

Manufacturing feasibility should therefore be considered during fastener selection rather than after the joint has been released.

When Does an EV Battery Fastener Need to Be Custom?

Standard fasteners should be used where they meet the engineering requirement.

Custom manufacturing becomes relevant when the application requires:

• Non-standard dimensions

• Special head geometry

• Special shoulder geometry

• Extended length

• Reduced installation height

• Integrated locating features

• Special anti-rotation features

• Application-specific sealing geometry

• Drawing-controlled material

• Customer-specific coating

• Unique thread-to-body geometry

• Integration with proprietary battery structures

Custom fasteners should solve a defined engineering or manufacturing problem rather than add complexity without functional benefit.

JUXIN FASTENERS can support drawing-based cold-formed, machined, stamped, and application-specific fastening components depending on geometry, material, quantity, and manufacturing feasibility.

What Engineering and Procurement Should Define Before RFQ

A common sourcing problem occurs when a fastener RFQ contains only:

Part Name + Thread Size + Quantity

That information may be enough to identify a commodity fastener, but it is often insufficient for an application-specific EV battery joint.

For more efficient technical evaluation, the RFQ should define the available requirements in several groups.

Fastener Geometry

• Fastener type

• Head style

• Flange diameter

• Thread size

• Thread pitch

• Length

• Grip length

• Under-head geometry

• Washer requirement

• Captive requirement

Parent Material

• Aluminum alloy and temper

• Steel grade

• Polymer grade

• Sheet thickness

• Wall thickness

• Cast material

• Reinforcement where applicable

Fastener Material

• Carbon or alloy steel specification

• Stainless steel grade

• Aluminum alloy

• Brass or copper alloy where applicable

• Polymer grade

• Heat treatment

• Hardness

Mechanical Requirements

• Tensile requirement

• Proof or yield requirement where applicable

• Torque/clamp-force requirement

• Pull-out requirement

• Spin-out resistance

• Shear requirement

• Fatigue requirement

• Prevailing torque

• Installation torque

Surface Treatment

• Zinc

• Zinc-nickel

• Zinc-flake

• Passivation

• Topcoat

• Sealant

• Lubrication

• Friction requirement

• Coating thickness

• Hydrogen-embrittlement controls where applicable

Assembly Conditions

• Manual or automated installation

• Installation tool

• Access direction

• Installation torque

• Required clamp force where specified

• Setting method

• Reuse requirement

• Production-volume requirement

Environmental Conditions

• Temperature range

• Thermal cycling

• Humidity

• Salt exposure

• Coolant exposure

• Chemical exposure

• Vibration

• Shock

Sealing Requirements

Where applicable, specify:

• Gasket type

• Seal material

• Compression requirement

• Leak requirement

• IP requirement

• Temperature cycling

• Chemical compatibility

• Leak-test method

EV Battery Fastener Quality and Documentation Requirements

Quality requirements should be defined according to the actual automotive program, drawing, customer specification, and component criticality.

Depending on the project, documentation may include:

• Material certificates

• Dimensional inspection reports

• Mechanical test reports

• Coating thickness reports

• Torque/clamp-force data

• Prevailing-torque test data

• Pull-out or spin-out test data

• Corrosion test reports

• Lot traceability

• Certificate of conformity

• Process-control documentation

• Customer-specific PPAP documentation where required

PPAP requirements and submission levels should be agreed during project development rather than assumed as a universal deliverable for every fastener.

The same principle applies to corrosion testing, torque testing, dimensional capability, traceability, and other documentation.

Specify what the program actually requires.

EV Battery Fastener RFQ Checklist

For faster technical evaluation, an EV battery fastener RFQ should ideally include the following information where available.

Application

• Battery tray

• Battery cover

• Module assembly

• BMS housing

• Cooling plate

• Structural frame

• Aluminum enclosure

• Power electronics enclosure

• Service panel

Parent Material

• Material specification

• Aluminum alloy and temper

• Steel grade

• Sheet thickness

• Wall thickness

• Cast material

• Polymer grade

• Reinforcement where applicable

Fastener Specification

• Fastener type

• Thread

• Diameter

• Length

• Head or flange geometry

• Grip range

• Material

• Mechanical property class

Surface Treatment

• Coating specification

• Coating thickness

• Lubrication

• Friction requirement

• Corrosion requirement

Assembly Conditions

• Manual or automated installation

• Installation torque

• Required clamp force where specified

• Tool type

• Access direction

• Setting process

• Reuse requirement

Environmental Conditions

• Temperature range

• Thermal cycling

• Humidity

• Salt exposure

• Coolant exposure

• Chemical exposure

• Vibration

• Shock

Performance Requirements

• Tensile

• Shear

• Pull-out

• Spin-out

• Fatigue

• Prevailing torque

• Corrosion

• Sealing

• IP requirement where applicable

Quality Requirements

• Dimensional inspection

• Mechanical testing

• Coating inspection

• Torque/clamp-force testing

• Surface-treatment documentation

• Traceability

• Certificate of conformity

• Customer-specific documentation

For custom parts, a 2D drawing or 3D model can significantly improve technical evaluation.

Providing the joint function and mating-component information can also be just as important as providing the nominal fastener dimensions.

EV Battery Pack Fastening Support from JUXIN FASTENERS

JUXIN FASTENERS supports industrial and automotive fastening projects involving standard and custom components for battery enclosures, 

aluminum structures, sheet metal, polymer components, thermal-management assemblies, and mechanical systems.

Relevant product and manufacturing capabilities include:

• High-strength bolts and nuts

• Weld nuts

• Projection weld fasteners

• Weld studs

• Blind rivet nuts

• Blind threaded studs

• Self-clinching fasteners

• Threaded inserts

• Blind rivets

• All-metal lock nuts

• Nylon insert lock nuts

• Plastic and nylon fasteners

• Cold-formed custom fasteners

• CNC machined components

• Stamped components

• Drawing-based automotive fasteners

• Application-specific surface-treatment coordination

Project requirements can vary significantly between EV platforms.

For this reason, material, dimensions, property class, surface treatment, inspection, traceability, packaging, 

and customer-specific quality documentation should be defined according to the actual drawing and program requirements.

For procurement teams, supplier evaluation should extend beyond unit price.

A technically suitable supplier should be able to understand the drawing, identify critical manufacturing characteristics, 

clarify ambiguous requirements before production, coordinate the required material and surface treatment, support inspection requirements, and maintain production consistency according to the agreed specification.

Engineering Takeaway

A reliable EV battery pack assembly is rarely created by selecting the strongest fastener available.

Joint performance results from the interaction between:

Fastener Geometry + Material + Surface Treatment + Parent Material + Joint Stiffness + Preload + Installation Process + Locking Strategy 

+ Thermal Expansion + Corrosion Control + Sealing + Manufacturing Variation + Validation

Before selecting or sourcing an EV battery fastener, engineering and procurement teams should ask:

1. What mechanical function must this joint perform?

2. Which parent materials are being joined?

3. How will the required clamp load or retention be achieved?

4. How will preload be maintained through vibration and thermal cycling?

5. How will aluminum-to-steel or other dissimilar-material corrosion risks be controlled?

6. Does the fastener interact with an enclosure sealing system?

7. Is one-sided installation required?

8. Does the joint require repeated service access?

9. Can the fastener be consistently installed and inspected in production?

10. What validation and quality documentation does the customer program require?

These questions turn fastener selection from a simple hardware purchase into an engineering and strategic sourcing decision.

JUXIN FASTENERS can support EV battery pack assembly projects involving standard fasteners, application-specific fastening systems, and drawing-based custom components.

For technical evaluation, sample development, or quotation, send your drawing or specification together with the parent material, material thickness,

 thread requirement, fastener material, surface treatment, installation method, joint function, quantity, and applicable inspection requirements.

Engineering & Sourcing: info@juxinfasteners.com

JUXIN FASTENERS
www.juxinfasteners.com