Terminal Crimping & Wire Termination Are Critical Processes for Reliable Electrical Connections

Terminal Crimping and Wire Termination are important processes in wire processing and wire harness assembly.

After wire cutting and stripping are completed, the conductor must be crimped or terminated according to the product specification and terminal design before proceeding to connector assembly and final wire harness production.

A reliable crimp is not simply a terminal pressed onto a wire. It is a controlled connection created by correctly matching the terminal, wire, and crimp tooling according to the applicable specifications.

SyncTronics Technology can evaluate terminal crimping, wire termination, and downstream wire harness processing requirements based on customer drawings, samples, wire specifications, terminal part numbers, connectors, and product requirements.

The Terminal, Wire & Crimp Tooling Must Be Properly Matched

Different terminals have different structures, applicable wire ranges, and crimping requirements. Even when two terminals look similar, they may not be suitable for the same wire size or processing dimensions.

Before terminal crimping, the following information should typically be confirmed:

・Terminal brand, series, and complete part number
・Wire / Cable specification
・AWG or conductor size
・Conductor strand count and construction
・Strip Length
・Conductor Crimp area
・Insulation Support area
・Specified Crimp Height
・Crimp tooling / applicator conditions
・Connector / Housing specification
・Pinout and Wire List
・Specified Pull Force or other acceptance requirements

Actual crimp dimensions and processing conditions should primarily follow the terminal manufacturer's Application Specification, customer drawings, and project requirements.

Different combinations of terminals, wire sizes, and crimp tooling may require different Crimp Heights and mechanical strength criteria. A single crimping parameter should not be applied to every terminal and wire combination.

For additional information on the basic principles of crimping, refer to 「What Is Crimping? How Crimp Quality Affects Electrical Performance and Reliability」。

The Conductor Crimp & Insulation Support Serve Different Functions

In a typical open-barrel terminal, the crimp area generally includes a conductor crimp section and an insulation support section.

The conductor crimp establishes the mechanical and electrical connection between the terminal and metallic conductor. The insulation support helps support the wire insulation and reduces the amount of pulling, vibration, or bending force transferred directly to the conductor termination area.

A completed crimp therefore should not be evaluated only by whether the terminal is physically attached to the wire.

Depending on the terminal specification, it may also be necessary to confirm:

・Whether the conductor is positioned correctly within the crimp area
・Whether the strands are properly inserted into the conductor crimp
・Whether the insulation is positioned correctly
・Whether the terminal shows abnormal deformation
・Whether the wire and terminal dimensions are properly matched

The preceding stripping process can also affect crimp quality. Excessive or insufficient Strip Length, or conductor damage caused during stripping, may result in incorrect conductor or insulation positioning within the terminal.

For related front-end processing information, refer to 「Wire Cutting & Stripping Services」。

Crimp Height Is an Important Process-Control Dimension

Crimp Height is an important dimensional measurement of the conductor crimp area after the terminal has been crimped.

It can be used to verify whether the finished crimp meets the specified processing conditions.

In general, excessive Crimp Height may indicate insufficient conductor compression, while an excessively low value may increase the risk of over-compression, conductor damage, or terminal deformation.

However, the acceptable dimension should not be determined arbitrarily.

Crimp Height should be defined according to the terminal part number, wire size, and terminal manufacturer's specifications rather than using one common standard for every wire harness.

Factors that may affect Crimp Height and process consistency include:

・Terminal specification
・AWG and conductor construction
・Crimp tooling / applicator settings
・Tooling condition and wear
・Wire and terminal conditions
・Equipment setup and process stability

For additional information, refer to 「What Is Crimp Height? Why Is It Important in Terminal Crimping?」。

Pull Testing Can Verify Mechanical Retention Between the Terminal & Wire

Crimp Height primarily provides information about the dimensional condition of a completed crimp. Pull Testing evaluates the connection from another perspective by measuring the mechanical retention between the terminal and conductor.

If a customer or terminal manufacturer specifies a Pull Force requirement, the test should be performed according to the applicable terminal, wire size, test method, and acceptance criteria.

Different terminals and AWG sizes should not automatically be evaluated using the same Pull Force requirement.

Therefore, Crimp Height and Pull Testing do not replace each other. They evaluate termination quality from dimensional and mechanical-strength perspectives respectively.

For additional information, refer to 「What Is a Pull Test?」。

Termination Quality Can Also Affect the Electrical Connection

Once the terminal and conductor are crimped together, the termination becomes part of the current or signal transmission path.

If the actual condition of the terminal, conductor, or contact interface is unstable, potential issues may include increased contact resistance, voltage drop, localized heating, or intermittent electrical contact.

For projects with specific reliability requirements, electrical verification may therefore be required in addition to dimensional and mechanical inspection.

For example, a Contact Resistance Test can be used to measure the resistance characteristics of terminals, connectors, and other electrical contact interfaces.

For additional information, refer to 「What Is Contact Resistance Testing? Measurement Principles, Standards, and Importance Explained」。

The dimensional, mechanical, and electrical inspections required for a specific project should follow the terminal manufacturer's specifications, customer drawings, and project acceptance requirements. Not every test should automatically be applied to every wire harness.

Crimping Is Not the Only Wire Termination Method

Wire Termination is a broader manufacturing concept, while crimping is one of the most common termination methods used in electronic wire harnesses.

Depending on the product structure and connection method, some wires may also use soldering or other termination processes.

The appropriate termination method should therefore be determined according to:

・Terminal / Connector structure
・Wire specification
・Product drawing
・Operating environment
・Production and assembly requirements
・Customer-specified requirements

rather than assuming that crimping is always better than soldering, or vice versa.

For a comparison of these common termination methods, refer to 「Crimping vs. Soldering: What's the Difference and Which Is Better?」。

Actual Terminal Harness Products & Processing Applications

Terminal crimping is widely used in power, control, signal, and other electronic equipment wiring applications. Different products may require different termination structures depending on the terminal type, connector, wire size, and pin configuration.

SyncTronics' 「VH3.96-6P-Ring terminal Wiring Harness」 combines a VH3.96 6-pin connector with ring terminals and serves as a practical example of a wire harness using different termination interfaces within the same assembly.

Another example, 「9V Battery Snap Connector with Wire Leads」, demonstrates a different harness configuration integrating a battery snap, wires, terminals, and a connector.

Although these two products use different structures, they demonstrate the same principle:

Terminal Crimping and Wire Termination conditions should be determined according to the actual terminal, wire, connector, and final product configuration.

In addition to these products, SyncTronics provides custom electronic Wire Harnesses using various terminal, connector, and wiring combinations. Processing and assembly can be evaluated according to customer drawings, samples, wire size, Pinout, and product specifications.

More related products can be found in 「Wire Harness」。

Confirm the Terminal & Wire Specifications Before NPI Prototyping

During new product development, product revisions, or terminal / connector replacement projects, the wire, terminal, Housing, and Pinout may require further confirmation during the prototype stage.

Before NPI prototyping, it is recommended to confirm:

Wire Specification
→ Strip Length
→ Terminal Part Number
→ Crimping Requirements
→ Connector / Housing
→ Pinout
→ Harness Sample

The applicable wire range, Crimp Height, and related processing conditions should follow the terminal manufacturer's specifications, customer drawings, or mutually confirmed production documentation.

If the terminal, wire, or Pinout changes after sample approval, the relevant production information should also be reviewed and updated accordingly.

Recommended Information for Terminal Crimping & Wire Termination RFQs

To improve specification review, prototyping, and quotation efficiency, customers are encouraged to provide:

・Product drawing or physical sample
・Wire / Cable part number and specification
・AWG or conductor size
・Terminal brand, series, and complete part number
・Connector / Housing brand, series, and complete part number
・Pinout / Wire List / wiring information
・Strip Length or specified front-end processing requirements
・Finished cable length and tolerance
・Specified Crimp Height requirement, if applicable
・Specified Pull Force or other acceptance requirements, if applicable
・NPI prototype quantity and estimated production quantity
・Product application and special environmental requirements

If the complete harness drawing has not yet been finalized, terminal and connector manufacturer part numbers, wire specifications, Pinout, and existing samples can still be provided for preliminary processing evaluation.

Need Terminal Crimping & Wire Termination Services?

If your product requires Terminal Crimping, Wire Termination, or custom Wire Harness processing, please provide your drawings, samples, wire specifications, terminals, connectors, Pinout, and estimated quantities through 「Contact Us」。

SyncTronics Technology can evaluate wire-to-terminal compatibility, crimping / termination, and downstream Wire Harness processing requirements based on customer-provided drawings, terminal / connector information, and product specifications. We support NPI prototyping, low-volume high-mix production, and OEM / ODM custom projects.

Actual terminals, wires, crimp dimensions, manufacturing processes, and acceptance criteria remain subject to final confirmation based on terminal manufacturer specifications, customer drawings, and project requirements.