Your no-fluff guide to advanced crimp tooling


At every stage of your production process, tooling decisions or requirements could reshape production costs and processes. They are an especially important variable in the equation of scaling production, and nobody wants to be held back by tools when there’s opportunity for growth.

In this article, we’ve detailed the various tooling options custom cable assemblers have at their disposal, including the most advanced technology available. You’ll find the pros and cons of each, along with pitfalls to look out for and questions worth asking potential suppliers to make sure they’re outfitted to own your project.

crimp hand tool
A standard crimping hand tool

Hand tooling

If your facility currently performs any of its own wire assembly, or if you’ve ever tinkered with custom cable at your home tool bench, then you’re probably familiar with some of the various hand tools for terminal crimping.

Most available hand-crimping tools are modular, at least to a point, to allow for flexibility and versatility across different wire gauges and crimp profiles. Some are more versatile than others. Set the tool based on gauge and crimp type, insert the wire, and crimp — one at a time, ad infinitum. It’s a simple process but a time consuming and inconsistent method at large volumes.

Different tools are quicker or clunkier to adjust to different settings, typically depending on their complexity or robustness.

Hand tooling is optimal for low-volume assembly, prototyping and field repair. But consistent, efficient, high-volume crimping by hand is no more possible than dry water or wooden iron. Luckily, there are plenty of better options.

Crimp applicators

A technological step up from hand tools is the crimp applicator — a machine that crimps a terminal to wire with a press mechanism. With the proper applicator stationed on a bench, an already-stripped wire is set on top of the terminal, and the press mechanism performs the crimp.

Applicators allow for more consistent precision and reduce the strenuousness of the labor required, but there’s still a fair bit of labor cost incurred in using applicators to perform crimping. You will still need to cut the wire and strip its jacket, either by hand or with a separate machine, before using an applicator.

It’s important, when thinking about machine applicators, to understand the ideal function of the applicator you’re proposing to use. They are graded to work on specific crimp profiles and specific wire types, and each applicator has a gauge range that is suggested. If an applicator is rated for 20- through 24-gauge wire, and you use it to crimp 18-gauge wire, the press may push the crimp too tight and damage your conductor. If that same applicator is used to crimp 26-gauge wire, the crimp may be too loose, and your terminal may not be secure enough.

How many different applicators could there be? Well, at Multi-Tek, we have over 150 unique applicators, so there can be quite a bit of variability. Using the right applicator is important for quality assurance, and if you’re using a third party for your cable assembly, they should be able to ensure you that they have the proper equipment. Most assembly designs fall into common categories and don’t cause any issues here, but tooling for some segment-specific crimps can be harder to find. Requiring tooling that your supplier doesn’t already have could carry additional costs.

Schleuniger StripCrimp 200
Applicators terminate crimps much more quickly and consistently than hand crimping

Strip-and-crimp machines

A strip-and-crimp machine provides the obvious benefit of being able to both strip and crimp wire in a single motion – saving up to 50% on labor costs. They can also be used to perform either function individually.

Strip-and-crimps come in handy when working with jacketed multiconductor cables, which require multiple terminals crimped to the different conductors held within a single cable. Just make sure that you allow for at least a 1.25” cable jacket removal to make use of these machines.

Using a strip-and-crimp machine, by performing two steps at once, cuts down on your equipment footprint as well as your production overhead and labor costs.

Cut, strip and terminate (CST) machines

Well then, what’s the absolute best way to crimp? What are the most advanced custom cable manufacturers using at their facilities? They are using CST machines for the bulk of their crimping.

Why? It’s right there in the name. A CST machine is able to cut, strip and terminate single conductor wire to specification in one go and is incomparable to hand-crimping and benchtop applicators in terms of throughput. The CST machine takes the applicator and supercharges it by placing it within a more complete assembly line and automating three steps of the process.

Wire is fed on a reel and cut and stripped before being automatically loaded into the applicator, which presses on the terminal and unloads the wire to make room for the next go-round. One particularly cool feature is the machine’s crimp force monitor, which recognizes when the crimp performed didn’t match the specified standard and disposes of it to make sure it isn’t mixed in with the proper crimps. They can also be augmented with pull-force test equipment to automate still another type of quality check.

Are there drawbacks? Yes, in that CST machines are expensive and carry a significant footprint. They are not typically economical for facilities that aren’t producing high volumes of custom cable. If wire assembly is just one small part of your facility’s production, it will probably be difficult to justify the expense. In addition, CST machines are incapable of processing jacketed multiconductor cable, so you need a separate process to properly crimp jacketed multiconductor connections.

What can go wrong if I’m crimping my own wire?

If you’re performing your own terminations in-house, it’s important to evaluate whether your tooling is limiting your production efficiency or cable quality. If you’re using hand tooling, that will be an obstacle to your ability to ramp up production and achieve economies of scale. It is also especially important to check your terminations for consistency, as achieving a perfectly repeatable quality with hand tooling is more difficult than with machine terminations.

If you’re using a benchtop applicator, be sure that you’re only using it for the particular crimps it is built for. If you use a machine to crimp wire outside its specifications, you are taking a risk in quality. Often, risking quality costs more than upgrading your equipment or outsourcing your production. If you’re using a benchtop applicator to perform crimps that could be managed by a CST machine or a stripper-crimper, it’s especially likely that a dedicated custom cable partner could manufacture your wire assembly with incomparable efficiency.

What can go wrong if I’m outsourcing custom cable assembly to a third party?

Tooling choices for in-house manufacture typically come down to evaluating needs and budget. If you’re outsourcing or considering outsourcing custom cable assembly, tooling will come down to the capabilities of particular suppliers and whether they are a right fit for your project. Your supplier will likely want to perform as much of their production using CST machines to save on cost and lead time, but whether or not they can do so effectively will come down to whether the particular cable and connector you’ve specified in your design can be assembled by an applicator in their arsenal.

If your design isn’t manufacturable with equipment that a supplier already has, they could take a number of steps:

  • The supplier may choose to purchase the machine (if they believe it will have lasting value for them) and cover the costs entirely on their end 
  • They may amortize the cost of purchase of the proper equipment to your order 
  • They may try to make do with an alternative machine used outside its intended application 
  • They may recommend an alternative supplier for that specific connection 

For the supplier to cover the cost of equipment’s purchase specifically to produce your design, they will probably need confidence in an ongoing volume of work. Or they may decide that the equipment will be useful for other potential work in the future and a worthwhile capital expense for that reason.

They may add incremental fees to their quote to cover some or all of their equipment costs. You should ask for transparency here—it’s worth understanding what steps your supplier is taking and why, in order to contextualize any additional costs.

Any good cable manufacturer will be up-front about a desire to use provisional equipment. Some may offer it as an option to save you costs. You should be sure to ask any potential supplier whether they have the specific equipment needed to manufacture your design at scale. If they plan to use alternative equipment, make sure you’re entirely comfortable with whatever additional quality management steps they plan to take.

Every custom cable manufacturer is not a great fit for every potential customer. Most cable suppliers know who they are built to serve, and many also know who may be better built to serve customers who aren’t best fits for them.

How to avoid tooling pitfalls

The easiest way to avoid running into tooling issues is to design using common wire types and connectors. This isn’t always possible. For a cable to be manufacturable, it must meet 100% of your needs — this is non-negotiable. That may not be possible with common specifications. Getting a custom cable manufacturer involved earlier in the design stage can prove helpful, as they may be able to offer suggestions related to tooling and manufacturability.

If you have questions about a design you’re currently working on or have tooling questions about a design already in production, feel free to reach out to us. We’d be happy to talk tooling and would love to learn more about what you’re working on.