Crimp Force Monitoring vs Pull Testing, Crimp Height and Cross-Section

Use crimp force monitoring to watch the production process, pull testing to check mechanical retention, crimp height to control geometry, and cross-sections to inspect the joint internally. No single result proves all four. Buying a tester is useful only when its measurement answers a defined acceptance question.

Begin with the terminal and tooling application specification for the actual wire construction. Molex’s application-tooling guidance directs users to the tooling specification for crimp height, strip length and pull-force requirements. A limit taken from another terminal with the same AWG can approve the wrong setup.

What each method tells you

Method	Useful evidence	What it does not establish alone
Visual inspection	Conductor position, visible strand damage, bellmouth and insulation position	Hidden internal geometry or electrical performance
Crimp-height measurement	Whether a defined crimp dimension stays within its approved window	Correct wire identity or every internal defect
Crimp force monitoring, or CFM	Whether a measured production signature deviates from a qualified reference	Pull strength, all defects, or connector seating after crimping
Pull-force test	Retention under the stated gripping and loading method	Long-term electrical performance or full internal geometry
Cross-section analysis	Strand distribution, barrel formation and geometry at the cut plane	The condition of every piece in the batch

TE’s crimp-height technical paper explains the role of dimensional control in a stable crimping process. Keep the measurement method and location consistent with the applicable terminal instructions.

Qualify a force monitor on your combination

A force monitor can flag changes associated with missing strands, misplaced insulation or tooling problems. OES lists these among the applications of its crimp process-monitoring systems. That capability still needs to be demonstrated on the wire, terminal and applicator being purchased.

We recommend an acceptance sequence that separates setup quality from detection performance:

1. Identify the wire, terminal, applicator and machine setup by part number or controlled reference.
2. Approve a stable set of normal crimps using the required visual, dimensional and destructive checks.
3. Establish the monitor reference from those accepted crimps.
4. Run clearly identified defect samples prepared under an agreed test plan, alongside normal samples.
5. Record detected defects, missed defects and false rejects separately.
6. Demonstrate what happens to a rejected part: stop, segregate or prevent release, as specified.

Keep deliberately defective samples out of production stock. Record the settings and part identities with the results so that a successful demonstration can be reproduced after changeover. Do not report “100% monitored” as “every possible defect detected.”

Make pull-test results comparable

Specify the terminal grip, load direction, loading speed, sample preparation, acceptance force and failure classification. Record whether the wire breaks, pulls out of the barrel or fails elsewhere. Follow the applicable method for whether insulation support participates in the test.

Our WM-817 manual terminal pull-force tester has a stated 500 N capacity. Match both the force range and loading method: a manual pull tester should not be treated as equivalent to a controlled-speed motorized tester when the test specification requires controlled speed.

Use cross-sections where they change a decision

Our WM-813 crimp cross-section system supports cutting, preparation and optical measurement. Define the section location and measurement criteria before comparing images. Preparation damage or an inconsistent cut position can make two otherwise similar joints look different.

For a new wire-terminal combination, agree the required checks before production approval. For routine production, set inspection intervals and restart checks from the customer’s control plan and process risk. For a defect investigation, retain affected samples and use our crimp-defect troubleshooting guide to connect the symptom to possible causes.

Choose the control plan before comparing cost

We recommend CFM where repeated production justifies monitoring each stroke and the defect trial demonstrates useful separation from normal variation. A new terminal, wire or applicator setup still needs its own approval. If the required defect cannot be distinguished reliably, use the appropriate dimensional, destructive or electrical inspection equipment and review the crimping setup instead of widening the monitor limits to make alarms disappear.

For occasional setup approval, compare the time and equipment needed for the specified crimp-height, pull and section checks. During a defect investigation, select the method that can reveal the suspected failure; repeating a passing pull test does not explain an internal geometry problem.

Budget the complete inspection plan: sensor integration and reference setup, calibration, fixtures, operator time, section-preparation consumables, destroyed samples and false-reject investigation. CFM’s cost per stroke and a laboratory cost per section have different denominators. Compare total inspection cost for the same released batch and agreed defect coverage. Do not assume that installing a monitor removes destructive tests required by your control plan.

Send the terminal specification, wire details and required inspection methods. We will match the quality-inspection equipment and any monitoring options to those requirements, with the scope confirmed on the quote.