Crimpers for automotive

[DoctorJelly]

Background: harley mechanic
Need: preferably 1 set of crimpers with hot swap dies to do basic electrical crimps (seen them all over amazon), but also more advanced stuff like molex, deutsch, wire seals, etc

[bookaboo]

Search for "Engineer PAD-11 PAD-12 PAD-13".
"Engineer" is a brand name of a Japanese firm, everything I've tried from them has been top quality.

[ksjh]

I own and use the Engineer PAD-11/12/13 set. It is good quality. But I think that for water-tight automotive connectors, you need additional/alternative tools, for example, the IWISS/iCrimp KIT-DC01 for Deutsch and Weather/Metri Pack or something like the ASTA A-RC3ST for the AMP Superseal 1.5mm series. I have not yet found a tool set with changeable dies for all these purposes.

[thm_w]

I would not buy the Engineer crimpers, they are non-ratcheting.

Its not clear what types you are talking about but basic insulated crimp tool is only $30: https://www.amazon.com/Klein-Tools-Ratcheting-Crimper-10-22/dp/B07WMB61J5/

Is that what you meant by "electrical crimps"? or something else.

[nctnico]

I would not buy the Engineer crimpers, they are non-ratcheting.

Agreed. If you use a non-ratcheting crimper, you might as well crimp contacts using your teeth. Crimping is a cold-flow process and a non-ratcheting crimper simply can't develop the pressure on the jaws needed to take the metal beyond the point where it starts to flow.

For Deutsch / AMP Superseal, a Heschen HS-03BC works OK for prototyping work. For anything professional or what needs to be durable / reliable, do yourself a favour and get the official crimper. It will be easier to work with and result in connections meeting quality standards.

[Smokey]

I would not buy the Engineer crimpers, they are non-ratcheting.

Agreed. If you use a non-ratcheting crimper, you might as well crimp contacts using your teeth. Crimping is a cold-flow process and a non-ratcheting crimper simply can't develop the pressure on the jaws needed to take the metal beyond the point where it starts to flow.
....

Bro.. sounds like you need to hit the gym, bro-sef!  Work on that grip strength, Bro-Jackson!
.... Do you even crimp?   

[notsob]

As a guideline, have a look at what Rhintoools in Australia sell - you should be able to find similar near you

https://rhinotools.com.au/product-category/crimping-tools/automotive-crimping-tools/

[nctnico]

As a guideline, have a look at what Rhintoools in Australia sell - you should be able to find similar near you

https://rhinotools.com.au/product-category/crimping-tools/automotive-crimping-tools/

As expected you can buy the exact same crimpers for less from Aliexpress. Search for Cinlin or Iwiss crimpers.

[DoctorJelly]

Appreciate you all! Busy season starting up and I was getting frustrated trying to find a master kit. With everybody's help I think I can piece together a kit that suits my needs. Would be nice if the dies were machined instead of MIM, but beggars can't be choosers!

[Siwastaja]

Crimping is a cold-flow process and a non-ratcheting crimper simply can't develop the pressure on the jaws needed to take the metal beyond the point where it starts to flow.

You are mixing two orthogonal things up. While ratcheting is an excellent feature because it prevents losing the force mid-way and forces the user to push till the end (which is usually adjustable) to release, it has nothing to do with the force per se; force comes just from the lever action so placement of the pivot point relative to the die, length of the handles; design of the handles is also important because if it is uncomfortable to press, then users are less likely to use enough force. But even for a non-ratcheting design, if those force-related details are well engineered then it's really fine.

[nctnico]

Crimping is a cold-flow process and a non-ratcheting crimper simply can't develop the pressure on the jaws needed to take the metal beyond the point where it starts to flow.

You are mixing two orthogonal things up. While ratcheting is an excellent feature because it prevents losing the force mid-way and forces the user to push till the end (which is usually adjustable) to release, it has nothing to do with the force per se; force comes just from the lever action so placement of the pivot point relative to the die, length of the handles; design of the handles is also important because if it is uncomfortable to press, then users are less likely to use enough force. But even for a non-ratcheting design, if those force-related details are well engineered then it's really fine.

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.

[tooki]

As a guideline, have a look at what Rhintoools in Australia sell - you should be able to find similar near you

https://rhinotools.com.au/product-category/crimping-tools/automotive-crimping-tools/

As expected you can buy the exact same crimpers for less from Aliexpress. Search for Cinlin or Iwiss crimpers.

Without seeing them up close and testing them, we cannot say whether those are the "exact same" tools or not. Iwiss and co slavishly copy others' tool designs, so the fact that they look the same doesn't mean they are the same. And as you surely know, in crimping, where success and failure comes down to tiny fractions of a millimeter, a glancing (or even close!) similarity simply doesn't mean anything.

[tooki]

Appreciate you all! Busy season starting up and I was getting frustrated trying to find a master kit. With everybody's help I think I can piece together a kit that suits my needs. Would be nice if the dies were machined instead of MIM, but beggars can't be choosers!

I highly suggest trying to get used or surplus original tools instead of no-name stuff. Cheap crimpers suck. If you'll be using this for your own pet projects, you may be willing to live with the risk of poor crimps coming apart. But if it's for customer work, invest in the real tools. Your customers, and your reputation, will appreciate it. Note also that original tools are generally easier to use (because they have locators to hold the terminals for you), which saves a lot of time (and thus money) and reduces errors.

[nctnico]

As a guideline, have a look at what Rhintoools in Australia sell - you should be able to find similar near you

https://rhinotools.com.au/product-category/crimping-tools/automotive-crimping-tools/

As expected you can buy the exact same crimpers for less from Aliexpress. Search for Cinlin or Iwiss crimpers.

Without seeing them up close and testing them, we cannot say whether those are the "exact same" tools or not. Iwiss and co slavishly copy others' tool designs, so the fact that they look the same doesn't mean they are the same. And as you surely know, in crimping, where success and failure comes down to tiny fractions of a millimeter, a glancing (or even close!) similarity simply doesn't mean anything.

I'm 100% sure. AUD150 (90 euro) doesn't buy you professional or quality crimping tools. Only Chinese rebadges with a big markup.

Even with brand names you have to be careful. For example, nowadays Gedore which is regarded as a high quality brand for tools, has a made-in-Asia economy line called Gedore Red.

[tooki]

Even at that price point there are differences in quality. That’s true even at the $15 AliExpress price point. There are numerous manufacturers of Chinese junk tools, of varying quality.

[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]

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).

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

[Siwastaja]

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.

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 ?

[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]

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.

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 ?

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.

[Siwastaja]

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.

The problem with "back of the envelope" calculations are while they are excellent to rule out ideas that are wrong by many orders of magnitude, being too close the actual numbers and their suitability for the case starts to matter. So you say producing 103kg of force with your hands is a problem. It sure is, but is 10kg, which would be off by just 10x?

So let's question your numbers, 120kg/mm^2 is a worst-case number "as high as" for a process which has absolutely nothing to do with cable crimping, but is a complete different process namely making mechanically robust joints between two sheet materials. I can imagine the force required is higher as the materials need to flow into each other deeper than when the idea is to just make a gas-tight electrically low-resistance joint as in crimping (where the deformation of the lug provides the mechanical support.)

And sure enough, if you take a look at for example https://uk.milwaukeetool.eu/en-gb/m18-force-logic-hydraulic-53-kn-cable-crimper/m18-hcct/ They claim they can crimp lugs for 300mm^2 wire. 300mm^2 wire lug has diameter of around 26mm or so, for a 10mm long crimp the surface area to apply pressure to is then 26mm*3.14*10mm = 800mm^2. Per your number, 120kg/mm^2 * 800mm^2 = 96000kg = 960 kN of force is needed to do that. Yet the Milwaukee only produces 53kN, less than a tenth of what you claim is needed. Does the Milwaukee live to its promises? I have no reason to doubt it. Now, can an adult apply 10kg of force with their hands? Sure they do, but doing that all day long would suck. Then again the Engineer product is not meant for all day long production work. I'm sure it survives the force of 100N for a long time, though.

So clearly the document which does not talk about wire crimping at all was not a very good resource, as expected. I understand why you chose it, though: it seems impossible to find any numerical data of electrical cable crimping pressure online. A lot of sources talk about how you should not apply "too little" or "too much", but no numbers.

Now I won't question the 1:7 lever ratio, from the photos it seems close.

Conclusion: calling something impossible by re-interpreting some numbers from completely out-of-context source is, while interesting, a risky business. I mean, all you need to do is to buy the tool and test it in real world use. Therefore I value the actual experience people are sharing, and the fact well known distributors keep selling this product, way higher than your theoretical back-of-the-envelope calculations trying to prove it would not work.

[nctnico]

How do you get to using the circumfence for a process that applies pressure from 1 side? It doesn't make sense. Like in a vise, force from one side gets opposed from the other side. And judging by the image, the length of the Milwaukee crimp is far shorter than 10mm. Besides that it likely takes a bit more math & modelling to calculate the amount of force needed / applied to a die to deform / compress a big round object compared to a small object that can be simplified to being flat and square.

Also, generic tool specifications doesn't mean they are actually suitable for the job. Sales people dream up all kinds of specs. You'd have to check the manufacturer's specification for the lugs you are using. And thinking that because well known distributors sell something, it is a high quality or even a suitable product is a mistake. Farnell -for example- sells lots of crap like leaky squeeze bottles (FFS!) and rebranded Owon/Hantek gear. I have been calling their Multicomp brand 'Multicrap' for good reasons for years. I also don't trust people who just look at crimps and say 'that looks nice'. I want to see data from pull-tests, analysis of the cold-weld process, etc before I (recommend) use (of) general purpose crimpers for connections which need to be reliable.

To get back to your 300mm^2 lug example, for this 300mm^2 lug:
https://www.etscablecomponents.com/product/two-bolt-copper-cable-lug-300mmsup2sup-w-m12-stud-holes-ct-300-c/

The manufacturer recommends this 130kN hydraulic crimper:
https://products.cembre.com/en/usa-canada-mexico/product/ht131-c

So likely the Milwaukee you found is not going to cut it unless it crimps a shorter area compared to the Cembre crimper. Electrical code is likely to say few words about the lenght of the crimps.

Anyway, the OP is looking to crimp low power contacts so discussing 300mm^2 crimps is quite far off the point.

[Siwastaja]

OK, so nctnico's list of...

Well Known and Respected Tool Manufacturers Who Still Manufacture Unusable Tools as Based on nctnico's Napkin Calculations:

• Engineer (the Japanese tool company)
• Milwaukee (professional series)

More?

Anyway, the OP is looking to crimp low power contacts so discussing 300mm^2 crimps is quite far off the point.

Yeah, still closer than non-crimping application of cold welding. You are free to post sources that state crimping forces for smaller connectors. I did not find any so I scaled down from a 300mm^2 crimp application for which numbers were available. Still closer than your non-crimping application.

[bookaboo]

I'm no expert on mechanical calculations, so this is a genuine question...
Doesn't the mechanical force need to take into account the area onto which it is applied? I.e the smaller the surface being crimped the larger the force acting on the crimp will be for the same input force and lever ratio?

But back to the real world, there are a hell of a lot of different crimps out there, probably thousands. Even if you take the 80/20 principle there are dozens of different crimps that a hobbyist or small workshop will come across. Hell even a large firm wont want to purchase expensive tooling for small volume or prototypes, so "good enough" tools often are well.... good enough.

I've made some very complicated looms for CAT and Deutz engines, if you are unlucky enough to have to build your own Exhaust After Treatment loom (don't do it kids), then this alone can be dozens of different styles of crimps. The PAD range is the best I've seen for getting close enough, and with some careful checking we have never had an issue (and these do on crushing and screening equipment so get a hell of a shaking).

Would I want these used on high volume production or safety critical equipment, probably not. But for most applications these are more than good enough.

[shabaz]

Hi,

A pull test will confirm the huge difference between a non-ratchet crimp result, and one done with a ratcheting crimper.
You can do that test using a tool that looks like a luggage weighing hanging device, but one that stores the value. After seeing the difference, you won't ever want to go back to non-ratchet (apart from non-critical use like prototypes for lab use).
For automotive, I'd be really unhappy to know if the engineer used a non-ratchet crimper.

[mendip_discovery]

For those that like the reassuringly expensive tools I think the 3M TR-490 might fit the bill for automotive use.

My shed just has a set of cheap red/blue/yellow, a un-insulated set and recently I bought a cheap hydraulic set for battery terminals. I do have it on my list to buy a set for doing old british bullet and modern Japanese bullet connectors.

[Siwastaja]

A pull test will confirm the huge difference between a non-ratchet crimp result, and one done with a ratcheting crimper.
...
For automotive, I'd be really unhappy to know if the engineer used a non-ratchet crimper.

So hydraulic crimper is not OK? Pretty interesting viewpoint, given these non-ratcheting tools are how pretty much all mission critical large crimps are being made.

Can you explain how the crimp knows if the mechanism had a ratchet or not, given that the crimping pressure and die shape are exactly the same, and pressure is applied in monotonically increasing curve? This is what hydraulic crimpers, lacking your beloved ratchet, do, and what we also emulate when we use hand tools without ratchets, which obviously are larger and need more care to use correctly. So can you explain where exactly does the difference come from?

[shabaz]

If you have tools capable of interfacing with a hydraulic system and designed to crimp with the required pressure, I don't see anyone suggesting you shouldn't use it?

My comment was in response to the person who suggested the PAD tool (which is not a hydraulic tool).

Not sure where you're going with "beloved ratchet". Can you keep the question technical without emotion, and I'll do my best (if I can) to answer it politely?

[shabaz]

For what it's worth, I can't completely recommend Knipex MultiCrimp but it's not bad.

The crimping dies are automatically attached/removed by pushing the crimper into the holder.
The tool has worked reliably, I have no complaint there, and it's comfortable to use, but a disadvantage is that there are only about half a dozen different crimping die choices.

The second photo shows how the hot-swapping works. The jaws are held aligned using a flip-out lever, and then the jaws are docked into the holder and a round metal button on the holder is pushed back to release the dies from the holder.

[nctnico]

A pull test will confirm the huge difference between a non-ratchet crimp result, and one done with a ratcheting crimper.
...
For automotive, I'd be really unhappy to know if the engineer used a non-ratchet crimper.

So hydraulic crimper is not OK? Pretty interesting viewpoint, given these non-ratcheting tools are how pretty much all mission critical large crimps are being made.

Can you explain how the crimp knows if the mechanism had a ratchet or not, given that the crimping pressure and die shape are exactly the same, and pressure is applied in monotonically increasing curve? This is what hydraulic crimpers, lacking your beloved ratchet, do, and what we also emulate when we use hand tools without ratchets, which obviously are larger and need more care to use correctly. So can you explain where exactly does the difference come from?

You missed the point where ratched crimpers have eccentric pivot mechanisms so you can build up the required pressure manually without needing a pump action tool (like a hydraulic crimper) to amplify the force from you hands. Just take a good look at a professional ratched crimper and you'll see that for each 'click' the jaws close less while the (angular) movement of the handles for each 'click' stays the same.

If you picture an eccentric (for example a piston + rod on the crankshaft in an engine) and rotate it starting from 90 degrees towards 0 (top dead center), you'll see that the amount of movement per degrees of rotation decreases when approacing 0 degrees. If you apply a constant torque + speed = constant power to the excenter, the closer you get to 0 degrees, the more force you can excert. This is because power = force * travelled distance. As the power (which can not be lost) is constant, the travelled distance becomes less the so the amount of force must go up. Tools like the engineer pliers don't have this feature and thus can't produce enough force on the crimp to create a cold weld.

[Siwastaja]

You missed the point where ratched crimpers have eccentric pivot mechanisms so you can build up the required pressure manually without needing a pump action tool (like a hydraulic crimper) to amplify the force from you hands. Just take a good look at a professional ratched crimper and you'll see that for each 'click' the jaws close less while the (angular) movement of the handles for each 'click' stays the same.

What makes you think I missed this? This is exactly why I mentioned that non-ratchet tools are significantly larger and more inconvenient to carry around and use: the handle length has to be dimensioned for the peak pressure, and then the total movement range must be larger because unlike the ratcheting version you described, die movement is linear to handle movement, so for anything larger you need two hands. But inconvenience and not working at all are two separate things.

From photos alone, I can't say if Engineer tools are good or not. But they are primarily for very small crimps so I have no reason to doubt their usefulness. We already saw that your calculation of 100kg of force was off by a factor of approximately ten. Sure, even with 10kg they are not convenient, but this amount of force is not impossible to produce, and if you mostly use them for smaller connectors than what you used for this calculation, I don't see a problem.

[Berni]

Non ratcheting crimpers are fine on some kinds of connectors.

IWISS brand tools from AliExpress are a very good deal for what you get for the price:
https://www.aliexpress.com/item/1005002766345160.html

The ratio between the crimp tool and handle is large enough to produce plenty of force to properly crimp the smaller wire gauge crimp pins. These simpler tools are cheap and since you crimp wire and insulation separately they are very flexible in what they can crimp. So 2 different sizes of these will crimp just about anything, from tiny 1mm JST to big automotive connectors. For the larger gauge wires >1mm2 the force requires starts getting pretty high so for those you really want to squeeze down as hard as you can both hands to make sure it is a good crimp. You can pick up 2 crimpers for 50 bucks easy and you are set. Only get fancier ones if you do a lot of crimping.

And yes i do pull test the connectors by grabbing it with pliers and pulling hard (before even crimping insulation), it takes an unreasonable amount of force to separate them, at what point the wire itself breaks or the connector pin rips apart. For large gauge wires, i don't have enough physical strength to reach the failure point by just pulling it with my arms.

So my advice is <1mm2, use regular pliers like crimpers. For wires <8mm2 you want to use racheting crimpers to avoid having to whale on the handle like a gorilla. For things bigger than 8mm2 use hydraulic crimpers. The big long handle mechanical crimpers for large gauge wires are crap (they don't make good crimps and it is a workout using them with how much force is needed)

If you need hydraulic crimpers for some big wires the chinese can get you one for like 100 bucks, i have a set and it handles 75mm2 wire just fine.

[tooki]

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.

You’re still confounding things.

Yes, nearly all ratcheting crimp tools use more complex mechanisms to give a large mechanical advantage. But a crimp tool with complex mechanisms for large mechanical advantage can be made without a ratchet. There are crimp tools like that.

Ratcheting does one thing, and one thing alone: it ensures you don’t release before a full cycle has been completed. No more. No less.

If, as is the case in many cheap Chinese crimpers, a full cycle doesn’t produce the right force or the correct dimensions, the crimp will still fail.

[tooki]

A pull test will confirm the huge difference between a non-ratchet crimp result, and one done with a ratcheting crimper.
You can do that test using a tool that looks like a luggage weighing hanging device, but one that stores the value. After seeing the difference, you won't ever want to go back to non-ratchet (apart from non-critical use like prototypes for lab use).
For automotive, I'd be really unhappy to know if the engineer used a non-ratchet crimper.

While nearly all good crimp tools have a ratchet, so do many cheap ones whose crimps fail. The ratchet only ensures a full cycle has been completed. The rest of the tool design is what actually determines the quality of the crimp. (If you were to take a good tool and remove the ratchet, it would continue to make good crimps, as long as the user always squeezes all the way.)

[tooki]

As for whether a crimp creates a cold weld, or is simply gastight: I think it depends on the type of crimp.

Indent crimping (as used in military and aviation/aerospace connectors, among other things) are definitely supposed to produce a cold weld.

On the other hand, insulated terminal crimps (the ones where you crimp the plastic collar), I don’t think those ever produce a cold weld. Gastight if you’re lucky. (Actually luck has nothing to do with it: like all crimps, success hinges on using the correct match of terminal, wire, and tool.)

[nctnico]

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.

You’re still confounding things.

Yes, nearly all ratcheting crimp tools use more complex mechanisms to give a large mechanical advantage. But a crimp tool with complex mechanisms for large mechanical advantage can be made without a ratchet. There are crimp tools like that.

I just wanted to simplify things. I know non-ratcheting crimp tools with progressively increasing force on the dies exist but I didn't want to add another facet to an already complicated topic. Add too many details at once and people get lost.

[Berni]

Yeah the point is not the racheting, more that the racheting ones tend to all have a mechanism inside that increases the mechanical advantage towards the end of travel to really squeeze that crimp down hard. Giving a better crimp and requiring less strain from the user.

The actual ratcheting part just removes the users hand feeling from the equation, making sure you put enough ooomph into it before it lets you complete it. Not really a problem if you know what you are doing and know to squeeze the living shit out of a regular non ratcheting tool when doing the thicker gauge wires. But a lot of the non ratcheting tools also don't have the special mechanism to increase mechanical advantage at the end, so for those you have to know to know to squeeze really really hard (and your hands might not appreciate it if you need to do 100 crimps).

As for wires sliding out of a crimp made with a racthering crimper. Usually it means you selected the wrong die size for the crimp pin, or used the wrong wire size for the pin. This is why (if possible) i tend to pull test a new unfamiliar combination of die+pin+wire to destruction first, then do the actual crimp.

[shabaz]

Agree with the comments from everyone above.
A while back I tried a Molex ratchet versus a generic ratchet tool. The Molex tool cost five times as much, but both appeared to produce strong crimps. The pull test amusingly showed a fivefold difference however.

Overly built down to a cost or bad ratchet tools, or ones with no indication of what crimp or wire size to use, and ratchet tools that might be used for different crimps they were not intended for, could be problematic. (Of course, the 'ratchet' is just a description and doesn't mean there are no other ways to achieve the force, e.g. 2-foot long crimpers, or hydraulic versions). 

A good brand name is one way to attempt to reduce the chances of buying a bad tool, but there might be cost-effective gems out there (especially for general prototyping use where you just want an electrical connection that won't be subjected to environmental conditions). Reviews/advice can help narrow down the choice, too, but a pull test will provide decent peace of mind.

[Siwastaja]

I didn't want to add another facet to an already complicated topic. Add too many details at once and people get lost.

The best way to make people confused and cause unnecessary hassle is to call X Y because there is an assumed correlation between X and Y, which you think is the case, but leave the fact you made such statistical assumption completely undisclosed, and simply instead call X Y.

The best way to avoid confusion is to keep clear, concise, and truthful, and use correct terminology. This way, leaving out details does not hurt, because one can always look for more detailed information, as the fundamentals are correct.

We have seen similar problems when people come up with made-up rules of thumbs in component specifications they think are true, but are not: for example, saying that increasing voltage rating of an MLCC cap increases usable capacitance under a fixed DC bias, while in reality this correlation is very weak, and better correlation would be had to (nominal capacitance / package size) i.e. volumetric energy density, than voltage rating. Even better is to keep short and truthful, and just say: look at the actual datasheet. This can't go wrong, and having "what if there is no data?" as the next step in discussion has the benefit that everyone will then know, from the context, that we are just speculating; better than going straight into speculation without saying so.

[shabaz]

I don't think it's as much of a problem here as you say. For what it's worth, to me, the comments so far were all clear. There's no trouble at all if someone asks for deeper advice or clarification, because others may be better at explaining particular detail (I for sure would not be able to explain the subtleties about change in force as the crimper is pushed further in, but I can certainly comment on the practical result from pull tests, and about any specific tools I have used that might be useful for the OP to rule in or rule out).

Most people in life are happy to clarify (if they can) when asked for advice. I think it's a normal life-lesson that you might not get a complete picture from just one paragraph or two. To work around that, sometimes I will seek the opinions of several people and then factor that into my decision. Regardless, it's still possible to end up with an unsuitable product/wrong capacitance/bad bargain.

You can try to change people to make them answer in correct terminology, might be an uphill struggle, or you can choose to accept that honest advice might have some qualification that's missing.

[tooki]

Writing for the target audience is a good thing, but it’s important to not oversimplify. A lot of people think that simplifying to the point of being wrong is okay, but it’s really not, and it’s really not necessary!! Skillful wording lets you formulate a statement that is both easy to understand and correct.

[shabaz]

That makes sense to me, and, as you point out, there's also a lot to be said for wanting to simplify to a level suitable for the target audience without deliberately introducing errors.

Unfortunately in practice, at one extreme, some people might struggle to put together a single sentence, and it might still be full of errors (such as mhz instead of MHz). I don't think anyone minds correcting things, it's no trouble for people (themselves or others) to hit the reply button and correct wrong assumptions or to add more details in areas they think they can assist in. That's how lots of information is discovered; people might not realize they are working on an assumption, and it takes others to point it out, and readers benefit from the discussion.

I should add, what's wrong is to deliberately reprimand or ridicule people for an honestly held opinion. In any case, Siwastaja didn't eat his own dogfood by keeping things concise. Instead, he resorted to untechnical, emotional terms like "beloved ratchet". On the other hand, maybe English isn't his first language, and he didn't realize how typical native English readers can interpret that. It cannot be expected for people to be language/grammar experts before they contribute to a forum conversation; people get things wrong.

Perhaps a slightly more ideal response to the OP would have been that the PAD tools are unlikely to be suitable for automotive use, and that attention should be directed to tools that can apply sufficient force, and they are typically likely to be (but not exclusively) ratchet-based tools, and [optional] here's the reason why....<xyz>". The xyz has been brought out in the longer discussion, by those who were able to better describe it.