Insertion and Withdrawal

Insertion and withdrawal testing is a critical method for evaluating the performance, durability, and reliability of components that require secure and repeatable connections. It is essential for products such as electrical connectors, fasteners, and closures where both ease of assembly and security of the connection are vital.

The process involves applying compressive forces to insert a component into its mating part, followed by tensile forces to withdraw it. This ensures components meet both functional and safety requirements under real-world conditions.

Industries including electronics, automotive, aerospace, and industrial manufacturing rely on insertion and withdrawal testing to verify that connections remain secure throughout a product’s lifecycle. Using precision test equipment, engineers can replicate operating environments, capture force-displacement data, and detect potential issues before they cause failures.

Insertion and withdrawal testing focuses on two key force measurements:

• Compressive force - the load applied when inserting a connector, fastener, or closure into its counterpart.
• Tensile force - the load applied when withdrawing the same component.

A well-designed connection must balance sufficient engagement force to prevent accidental disconnection with an acceptable withdrawal force to allow servicing without excessive effort.

Force-displacement curves generated during testing show the full insertion and extraction profile, allowing engineers to:

• Identify manufacturing inconsistencies
• Compare performance over repeated cycles
• Assess the effect of wear, contamination, or temperature on retention performance

Motorised test systems are often used to maintain uniform speed and alignment, delivering consistent, repeatable results.

For electrical connectors, insertion and withdrawal testing is essential to ensure reliable contact, mechanical robustness, and compliance with relevant standards.

Typical procedure:

• Fixture setup - the connector and mating component are mounted in an alignment fixture.
• Controlled insertion - a motorised test stand applies compressive force at a defined speed to engage the connection fully.
• Measurement of insertion force - the peak force required for engagement is recorded.
• Controlled withdrawal - the direction is reversed, applying tensile force to separate the components.
• Measurement of withdrawal force - the peak extraction force is recorded to assess retention strength.

Specialised jigs may be required for different connector geometries. Standards such as BS EN 5057, IEC 61210, and IEC 60512-13-2 define test conditions to ensure accuracy and repeatability.

Extraction resistance is the connector’s ability to maintain a secure fit during use while still allowing disconnection when necessary. This is especially important where connectors are repeatedly mated and unmated, such as:

• Aerospace and defence systems subject to vibration and temperature variation
• Industrial automation equipment requiring rapid maintenance and replacement
• Consumer electronics where connectors must be secure but user-friendly

In aerospace and defence, cyclic insertion and withdrawal testing verifies that connectors maintain performance over many engagement cycles.

Insertion and withdrawal testing is not limited to electrical connectors. It is used to validate the performance of:

• Fasteners - push-fit and snap-fit designs in automotive assemblies, often tested for forces between 100 N and 300 N.
• Closures - caps and plugs in packaging and fluid handling, where opening forces must remain within consumer-friendly limits.
• Terminals - electrical crimps and spade connectors in power distribution systems.

In automotive manufacturing, tests ensure that interior trim fasteners hold securely but can be removed for servicing without damage. In packaging, the method validates that push-fit closures provide a proper seal without excessive opening force.

Adhering to industry standards ensures consistency, repeatability, and compliance. Key standards include:

• BS EN 5057 - methods for assessing electrical connector performance, including insertion and withdrawal forces.
• IEC 61210 - mechanical testing for connector terminals with defined extraction force requirements.
• IEC 60512-13-2 - test methods for insertion and withdrawal forces in electrical connectors across multiple cycles.

Sector-specific standards may define acceptable force ranges and environmental test conditions for particular applications.

Mecmesin provides high-precision systems for measuring insertion and withdrawal forces across a wide range of components.

Capabilities include:

• Motorised crossheads for precise and consistent test speeds
• High-resolution load cells for accurate force measurement from below 1 N to over 50 kN
• Customisable fixtures for micro-connectors through to heavy-duty industrial fasteners
• Integration with VectorPro software for live force-displacement graphs, statistical analysis, and automated reporting
• Compliance with BS EN 5057, IEC 61210, IEC 60512-13-2, and other sector-specific standards

Equipment options include the OmniTest and MultiTest-dV ranges, ensuring suitability for laboratory testing, quality control, and high-volume production environments.

If you need accurate and repeatable insertion and withdrawal testing for connectors, fasteners, or closures, Mecmesin’s technical specialists can help you select the right equipment, develop test methods, and ensure compliance with industry standards. Our systems deliver the precision, consistency, and data analysis capabilities required to optimise product performance and reliability.