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My Top Tips for Making the Perfect Crimp with FCT from Molex

The heart of every connector is the contact. Whenever I talk to someone about cable connectors, I somehow get on to the subject of wire termination. When using cable connectors, most customers choose between crimp or solder termination. Both methods have their advantages, but I have long been a champion of crimp technology. Maybe it's because my soldering skills are so rusty, but a well-made crimp termination gives me a warm feeling.

FCT Crimp Tool

In my experience, a good solder joint needs a reasonable amount of skill to complete, and it's a skill that needs to be practised. In contrast, crimping uses a tool to produce a consistent termination time and again, without the need for specialist skills. The amount of training required to operate a crimp tool is far less than that of a soldering iron, allowing engineers to concentrate on working rather than learning. Neither does it require high temperatures or potentially hazardous materials, making it a great solution for enclosed or difficult-to-reach locations.

Combining Electrical and Mechanical Reliability

So, to work properly, the crimping process deforms the strands of the wire so that it creates a gas-tight joint. This means that there is the greatest possible surface area for electrical contact and prevents oxygen or moisture from reaching the metal of the wire and terminal, which reduces the possibility of corrosion.

If the crimping process doesn't make this gas-tight seal, the electrical resistance of the joint is higher than desired, making it less efficient. This can be dangerous, especially where the terminal is used for power circuits. A terminal with high electrical resistance will generate excess heat when sufficient power travels through it. At its highest, this may exceed the safe working temperature of the connector, leading to anything from plastic parts melting to a possible source of fire. For this reason, mechanical testing should be a key part of cable preparation.

Alongside the electrical performance, it's important to consider mechanical strength. The crimping process is designed to ensure that the wire is secured firmly within the terminal. A mechanical joint with insufficient compression will not retain the wire within the terminal with enough force to prevent it from falling or being pulled out. But beware - compressing the wire too much will weaken its mechanical strength and will potentially damage the terminal.

Dedicated Tooling

But what about tooling? Good crimping needs a crimp tool, configured with the right settings and used in accordance with the published instructions. Without any one of these elements, the system will not perform correctly.

Customers often complain to me that the drawback of a crimp system is the cost of the tooling, which can easily be the most expensive part of this system. But my advice is always that the value of a dedicated crimp tool is that it has been created to perform several complex operations whilst being simple and straightforward to use. The jaws of the tool shape the metal of the terminal in such a way to create the ideal gas-tight seal, and the positioner is designed to hold the wire in just the right position. This precision only comes with the right crimp tool along with the hours of testing, thousands of prototypes, and pages of documentation that the manufacturer creates.

Despite this, the cost puts people off and sometimes they are tempted to take matters into their own hands. More than once, I've seen customers trying to terminate their contacts with a pair of pliers, and it makes my blood run cold. I could tell you some horror stories from customers who assumed that any old crimp was good enough. The resulting disasters range from equipment failure to catastrophic electrical fires.

Use The Right Tool

Crimp terminations are great. They are strong and reliable, and they remove the need for dangerous high temperatures or highly skilled operators during production, but they do come with a cost. The crimp terminal is just a small part of a complete system, and it's a system that the manufacturers have spent a long time perfecting.

So please don't risk your equipment by ignoring the manufacturer's specifications. If something goes wrong, the first question they will ask when you complain is how the contact was terminated. Do you really want to tell them that you used a cheap pair of pliers?

In summary, without the correct crimp tool, the system is compromised, and cable termination is left to chance. By choosing the right crimp tool for your application, you can take advantage of the decades of expertise delivered by Molex FCT and ensure that your cable terminations are safe and secure for years to come.

Connector Geek is Dave in real life. After three decades in the industry, Dave still likes talking about connectors almost as much as being a Dad to his two kids. He still loves Lego too. And guitars.
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