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Appropriate Ratchet Crimping Tools


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Nearly EVERY standard ratchet crimping tool on the market for uninsulated terminals has the two anvils for the part that grips the conductor and the part that grips the insulation at the back at the same height, so it assumes the "back" of the terminal is flat. Like this:


Which suits terminals similar to this:


The problem is ... in real life MOST terminal series are NOT flat! Especially those for sealed connectors.

e.g. on the K Series engine loom: Econoseal III 250 (MFRU Out):


Standard Econoseal  070 (Many Uses):


Micro Timer II (ECU):


All of these and many others have the seal grip part dished downwards (which kind of makes sense as you want it to crimp into a larger radius circle around the cable seal).

Now Durite do a reasonably priced crimper for Econoseal terminals that has the anvils aligned correctly. You can see here how the two parts of the lower anvils are offset at different heights.


To be honest with standard Econoseal, you can get away with standard generic crimpers, and most people do. I'm a perfectionist though so I've got the Econoseal crimper too, and for a lot of the other smaller dished type terminals like Micro Timer II it also works quite well. But if you try crimping larger sealed terminals like Econoseal III 250, every standard crimper just crushes and breaks the rear part of the terminal horribly. The Durite Econoseal crimper doesn't have anvils large enough for these terminals and flat crimpers just crush the seal grip.

IMG_20200807_224950.thumb.jpg.0b427968f765505a85bcd4ace2a37e48.jpg  IMG_20200807_224939.thumb.jpg.39a2bd0f3910163d386fac218ae59319.jpg

(These were just test crimps so I missed the seal out to allow you to see what had happened).

These are clearly unacceptable crimps and I wouldn't feel at all comfortable supplying somebody with a loom with crimps like that in it.

There are specific crimpers available from the terminal manufacturers for specific terminal series - they can cost hundreds of pounds each.


An body know of anything out there?

This has frustrated me for years! Never found anything reasonably priced that would do the job.

My current plan is to take an old standard crimper and trim the anvils back with a die grinder to make my own.

(OK: Admission time. I tried it. I made one for Econoseal III 250, it worked beautifully. Except I though maybe it needed just a little bit more off ... and I ruined it! So my "current plan" is actually a second attempt).

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I have a generic crimper with interchangeable jaws that have stepped recesses for the insulation crimp:

BD77C526-DEFE-4315-9A92-D9294A656FF4.jpeg.4f5e91cda5a9e57399ecb22093394f16.jpeg 0F402DD7-88D4-40BE-959F-D3D2E6717B35.jpeg.a73b39cc432ae6b09b0fcba71dc15486.jpeg 091EAAE4-F25A-4013-8B2A-D38F76C63B28.jpeg.657e9a5e8be92714b7e5cb08de482e8b.jpeg 4EA9F607-D17E-43B9-B0AE-54AB1E9F7030.jpeg.2cc39f071467faa30cca82d539adaba4.jpeg

I also use an auto-stripper that gently clamps the insulation and removes the right amount, based on the adjustable "screen" position, makes stripping accurate and repeatable:

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The Pro-Point brand name for tools seems to be used in Canada, I paid $80 (£46) for my set. This seems to be the same one available in the UK: https://www.amazon.co.uk/Astro-9477-Professional-Interchangeable-Tool/dp/B0045CUMLQ


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Is that a TE / Tyco crimp connector? If it is then there will be a defined crimp tool for it, and if you are lucky there will be an RS copy of it that will cost about 1/4 of the price, but will infact be the same tool. I have just bought one to do proper TE butt crimps for my loom rebuild. The TE one is £199.00, the same tool with RS badging is £31.00. 

If it is a PIDG style connector then Ebay is good for cheap used TE tools, I have picked up a few FASTON style tools that were in the £800.00 range for less than £30.00. If you have a specific tool in mind it is worth setting up an ebay alert for it.

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Thanks guys.

Are you absolutely sure that the backs of the dies on those crimpers are stepped?

They seem to be sold under a number of different brands with the same dies. The open barrel die seems to be "Type C". But all of the images I've been able to find on Google for these seem to show a flat back like most other tools, like this:


Most tools are stepped on the "open" side of the crimp, but I need ones that are stepped on the back or "closed" side too.

I'm just worried that if I don't buy exactly the same brand, I'll pay £100 and end up with just another crimper.

The other slight frustration/worry is that all of these tools have jaws for 1.5-2.5mm² and 4-6mm² and I'm crimping 3mm² wires into terminals specified for 2-3mm², which falls right in the gap between the two. My ordinary ratchet crimpers, as well as destroying the insulation part of the terminal, did seem to be over-crimping and distorting the terminal in the 1.5-2.5mm² jaws and using the 4-6mm² jaws I could easily pull the wire out afterwards so the crimp had failed.

When I had to crimp some tiny terminals like the Multilock 040 terminals in the immobiliser connector I found standard open barrel crimpers to be far too large and I bought a pair of these Molex service pliers which actually did them very nicely:


The disadvantage of these is that you have to do the conductor and insulator/seal in two steps... which takes a bit more time.

The advantage of these is that you have to do the conductor and insulator/seal in two steps... which means that any relative offset between the two is irrelevant.

For small terminals the pressure was OK. For larger terminals though, they just don't have the leverage to produce enough pressure though. I tried using the larger anvils on these to crimp some Econoseal 250 terminals onto 3mm² wires just now. You can produce some beautifully formed neat crimps, but again the wires will just pull out as not enough pressure is applied.

When I was looking into these before those I did see these:



Japanese Hozan P-707. Generally you have to order them from Japan. They look nicely made and reviews seem generally positive, the only real criticism being that they crimp the two parts separately.

They are sort of a compromise bewtween the two. They look like they will combine the ability to crimp the two parts separately (avoiding the "step" issue) with a double-lever mechanism similar to those used on the more traditional ratchet pliers to get the extra leverage pressure. Sensibly the larger sizes of conductor crimps are closer to the pivot too. And being non-ratchet, I would imagine you can modulate the pressure as you don't need to go completely closed before releasing if that damages the terminal.

With the Molex pliers I found I could just about get a decent crimp on these terminals if I first "formed" the crimp using the 3.2mm insulation jaws, then "tighten" it using the 2.5mm conductor jaws, although these did distort the terminal a bit. This suggests that an appropriate size may be somewhere between the two and the Hozan tool has some 2.9mm jaws so these would probably be about right.

For my use, having to do the two part separately really isn't an issue. I'd much rather get neat, solid reliable crimps than save a few seconds. I'm not producing looms on an industrial scale. I think that particular tool might just cover a whole range of difficult cases and terminal types which don't easily fit standard ratchet crimpers.

Anyone on here ever used the Hozan P-707?

Thanks as always,


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I've not used any of the crimpers mentioned, but personally I prefer the flexibility and control of the two step process, so would definitely opt for the Hozan if it didn't waste half the jaw space (and leverage) with silly wire strippers.

I have had a couple of old Molex tools for 30years+ (both non-ratchet) and between them they've been used many, many different types of terminal without any problems:-


e.g. I'd never used Econoseals before getting the Seven, but found the larger tool worked just fine with them. The hooked end helps starting the round-over onto the seal , and the round opening adjacent allows the ends to be snugged down. No drama, split boots etc.

It's actually still available as a Molex QM multipole crimper RS 468-686, but the smaller (and cheap) Molex KK one has long been superceded by a £300 ratchet device which does the same job but is more idiot proof...



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Hi Barry,

Yes I think the more I look at things the more I'm leaning towards the two step process myself.

Thanks for the RS link.

I don't think the particular Hozan model I linked to has any wire strippers? It has a wide selection of different crimping jaws in two ranges, one for the conductor and one for the insulator. I think the main difference is the size.



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  • 2 weeks later...

Well I said I would report back ...

To be honest the Hozan was a bit of a disappointment. It looks well made and will probably work nicely on some of the smaller terminals like Micro Timer II (ECU), but the double lever mechanism means that jaws just won't open wide enough to get Econoseal 250 terminals into it!

In the end I played around with the Molex service pliers and found that if you use EXACTLY the right jaw sizes for the conductor and insulator (which I had to find by trial and error) and the right amount of pressure you can get a reasonable enough result. I was worried they wouldn't apply enough pressure ... in reality the problem is that they can apply too much and easily crush and damage the terminal, so you need to learn by feel how much to squeeze them. Maybe not ideal for a professional mass production scenario but I think I can manage with them with care.

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