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Crimpers for automotive

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bookaboo:
Those Klein are insulated crimpers, I agree you do need ratcheting crimpers for those.

However the Engineer crimp set is designed to cover the plethora of random crimps found in automotive.... and there are a hell of a lot. The PAD sets cover 90% of these (notable exception Deutsch).
If you want to order the proper official manufacturer set for every crimp family, be prepared to spend multiple thousands (not to mention the waiting).

Of course they are not perfect, if you find yourself doing lots of the same crimp then best invest in something specific. But these are great for covering one offs or a few specials.

tooki:

--- Quote from: bookaboo on March 09, 2024, 05:47:02 am ---If you want to order the proper official manufacturer set for every crimp family, be prepared to spend multiple thousands (not to mention the waiting).

--- End quote ---
The waiting…? Huh? They’re usually in stock somewhere.

Siwastaja:

--- Quote from: nctnico on March 08, 2024, 07:27:59 pm ---The latter is the problem. It is not well engineered. The relatively thin ends of a tool like the 'engineer' pliers are way too flexible to produce the required pressure. If you can squeeze that hard (which is unlikely). A ratcheted crimper produces way more force on the crimp for the same input due to how the mechanism works to amplify the force from the handles to the die. So no, I'm not mixing anything up. Just take a ratcheting crimper and notice how the amount of travel of the jaws is reduced for each 'click' the jaws close further but the travel distance for the handle stays more or less constant. There is also a typical difference between the cheap Chinese crimpers and the professional ones. The professional ones typically have a much more sturdy construction (more steel plates in parallel or thick solid steel) compared to the cheap crimpers.

--- End quote ---

Well, I have used some very large crimpers for 100-200 mm^2 wire lugs, without the ratchet function, and they have been just fine, with handles almost a meter long. Hydraulic crimp tool would be easier to carry around and use and offer better force density, but really a lever provides the same force amplification, it's known for thousands of years.

About the quality of the Engineer crimp tool, have you actually tried those? I haven't, but have mostly heard good and it's a well known high quality brand. It is very difficult to say from the photos how they really perform. So do you have real experience of this exact product or just generic :blah: ?

voltsandjolts:
https://www.engineertools-jp.com/crimpingstripping

I use the Enginner PA-09 and PA-20, intended for electronic engineer stuff but might be suitable for some pin styles used on automotive, not sure.

To me, these crimpers are indispensable because they do a reasonable job and are very versatile, usable on lots of crimps. However, they need care to use. I have to use magnifiers to see that I am placing the wire and crimp correctly before pressing. There are no guides that you would get on expensive crimping pliers designed for specific crimps.

If versatility is important, I would recommend the Engineer tools.
If you are doing a lot of the same style of crimp, spend the money and get specialist tool.

nctnico:

--- Quote from: Siwastaja on March 09, 2024, 09:49:35 am ---
--- Quote from: nctnico on March 08, 2024, 07:27:59 pm ---The latter is the problem. It is not well engineered. The relatively thin ends of a tool like the 'engineer' pliers are way too flexible to produce the required pressure. If you can squeeze that hard (which is unlikely). A ratcheted crimper produces way more force on the crimp for the same input due to how the mechanism works to amplify the force from the handles to the die. So no, I'm not mixing anything up. Just take a ratcheting crimper and notice how the amount of travel of the jaws is reduced for each 'click' the jaws close further but the travel distance for the handle stays more or less constant. There is also a typical difference between the cheap Chinese crimpers and the professional ones. The professional ones typically have a much more sturdy construction (more steel plates in parallel or thick solid steel) compared to the cheap crimpers.

--- End quote ---

Well, I have used some very large crimpers for 100-200 mm^2 wire lugs, without the ratchet function, and they have been just fine, with handles almost a meter long. Hydraulic crimp tool would be easier to carry around and use and offer better force density, but really a lever provides the same force amplification, it's known for thousands of years.

About the quality of the Engineer crimp tool, have you actually tried those? I haven't, but have mostly heard good and it's a well known high quality brand. It is very difficult to say from the photos how they really perform. So do you have real experience of this exact product or just generic :blah: ?

--- End quote ---
You really underestimate what is involved in crimping. I don't and from there, I can simply see the engineer pliers are no good. A good crimp is more than just folding the tabs over the wires in a neat way.

As I wrote before, crimping is a cold flow / cold welding process which requires extreme pressures. The goal is to weld the contact to the wire so they become one single piece of metal. Only then, and only then you'll get a connection which is resistant to vibration, corrossion and thermal cycling. Keep in mind that contacts and wires are dissimilar materials with different temperate expansion coefficients so thermal cycling is going to have an effect when the tabs of a contact are just clamped around the wire (instead of welded).

But let's apply some back on the envelope math:

In this PDF https://mtmmachines.ca/wp-content/uploads/2020/11/MTM-TP-Cold-Welding-R0.pdf it says that for cold welding to happen, you need to apply pressures over 12000kg/cm^2 (= 120kg/mm^2).

If you take a Molex KK-256 contact for example, the crimping area is about 6mm^2. For the cold welding process to happen you'll need 6*120 = 720kg of force on the jaws. Say you get a 1 to 7 lever effect from the Engineer PAD-11 (which is advertised for use with Molex KK-256), you'll need to produce a force of 720 / 7 =  103kg with your hands. An average man can produce 49kg of force by hand in his prime years. All this while assuming the Engineer pliers do not bend when they need to cope with these kind of forces. I hope this makes it clear that the engineer pliers are not suitable for reliable crimps as they simply can't produce the pressure required for the cold welding process. I hope it also shows why the likes of Molex, JST, etc don't supply simple crimping pliers for use with their crimp contacts; these won't create reliable crimp connections.

As a side note: hydraulic crimpers for big lugs can apply tens of tonnes of force to the crimping dies in order to make the cold weld process happen.

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