Insulated crimp terminal diameter issue, KNIPEX / Molex / TE / AMP

[iroc86]

I use KNIPEX Crimp System pliers for most of my crimping needs and ran into an unexpected issue with Molex Insulkrimp terminals. When crimping female quick disconnect (QD) terminals, the crimps are rather mediocre and the wire tends to pull out. Any other Insulkrimp terminal is very secure and reliable. Have any of you experienced this before?

It appears that the insulated sleeve on QD terminals has a slightly smaller outside diameter compared to everything else. I measured a ~.030" (0.8 mm) difference between a 14-16 AWG female QD and ring terminal. I'm not sure why Molex would mold a completely different insulation sleeve for just the QD stuff when the wire cavity geometry underneath is surely the same for the rings, spades, and splices.

Molex actually sells a completely different crimper just for Insulkrimp quick disconnect terminals. My KNIPEX crimper die matches their "everything else" crimper, which explains the poor performance on the QD stuff.

Short of buying a different crimper, do other manufacturers of insulated terminals use larger ODs on their quick disconnect crimp terminals? I've looked at 3M, Panduit, and TE, but they don't provide dimensions of the insulation sleeves in their engineering drawings. Maybe someone would be willing to measure the terminals in their junk bin? I only have Molex stuff here. For reference, the two diameters are .189/.206" (4.8/5.2 mm) for the female QD and .217/.235" (5.5/6.0 mm) for the ring.

[nctnico]

I have given up looking at the color codes a long time ago. I make a test crimp and if I can pull the wire out then I use the smaller opening.

[wraper]

Seem to be perfect match for red die. I don't have quick disconnect terminals where I'm right now but I don't remember any size difference with other connectors. Although I did not buy any Molex branded connectors of this type.

[wraper]

Your connector probably use thin insulation, this is what I usually use.

[iroc86]

... I make a test crimp and if I can pull the wire out then I use the smaller opening.

Seem to be perfect match for red die. ...

I tend to make test crimps myself, and the red die does work fairly well on the blue terminals... but I have some red ones to crimp next and I can't go any smaller .

wraper, would you be able to measure the diameter of those terminals with the thicker insulation? I think I had a few of those in the past, but I was using a different crimper at the time.

[mzzj]

Maybe you get better luck if you look for "double sleeve" terminals.

From my own stashes the  Taiwanese K.S. terminals are 5.0mm,  Abico double sleeve (swedish brand) are ~5.8mm.
K.S. ring terminals are 5.8mm 

It looks like Molex Avicrimps have larger gage measure(based on some pdf that I'm not able to find again..)
Avikrimp is also double sleeve unlike insulkrimp

[iroc86]

Thanks for those measurements, mzzj. Can you clarify if the Abiko terminals that measure 5.8 mm OD are "quick disconnect" or just ring/spade? I ask because Abiko appears to make the various Molex crimpers that are required across these different diameters. It'd be interesting to know if Abiko has the same such variation among their own terminals. (Compare Abiko's KSAC0760 with Molex's 64001-0100, -200, and -400. Looks identical to me, save for the dies. All are made in Sweden, too.)

After researching the crimp die dimensions among Molex, Panduit, and TE, I came up with a compromise without having to buy a bunch of dedicated tools. I'll use my KNIPEX crimper for Molex Insulkrimp ring, spade, and splices, as its die geometry matches the Molex 64001-0100 application spec [PDF]. For the quick disconnect terminals, I picked up a used AMP/TE 59824-1 crimper which is supposedly compatible with all insulated TE FASTON terminals, as well as some of their other PIDG and PLASTI-GRIP terminals and splices. The AMP tool may also work with a few Panduit terminals that specify their CT-1525 tool, notably the nylon DNFR-B insulated flag terminals (those are nice because they have an extended crimp barrel and don't require a dedicated flag terminal crimping tool).

One could probably make a full-time job out of understanding the application guidelines for crimp terminals! I can report back when I receive the AMP crimper and new terminals. In the meantime, I'd still be interested in hearing any input and experiences from you all.

[SilverSolder]

I have also been disappointed that my "better quality" crimper often fails to do a good job.

When all else fails, the cheapest/crudest type of crimper usually gets the job done...

[iroc86]

When all else fails, the cheapest/crudest type of crimper usually gets the job done...

You mean teeth? I knew a guy who used to do that...

[mzzj]

Thanks for those measurements, mzzj. Can you clarify if the Abiko terminals that measure 5.8 mm OD are "quick disconnect" or just ring/spade? I ask because Abiko appears to make the various Molex crimpers that are required across these different diameters. It'd be interesting to know if Abiko has the same such variation among their own terminals. (Compare Abiko's KSAC0760 with Molex's 64001-0100, -200, and -400. Looks identical to me, save for the dies. All are made in Sweden, too.)

After researching the crimp die dimensions among Molex, Panduit, and TE, I came up with a compromise without having to buy a bunch of dedicated tools. I'll use my KNIPEX crimper for Molex Insulkrimp ring, spade, and splices, as its die geometry matches the Molex 64001-0100 application spec [PDF]. For the quick disconnect terminals, I picked up a used AMP/TE 59824-1 crimper which is supposedly compatible with all insulated TE FASTON terminals, as well as some of their other PIDG and PLASTI-GRIP terminals and splices. The AMP tool may also work with a few Panduit terminals that specify their CT-1525 tool, notably the nylon DNFR-B insulated flag terminals (those are nice because they have an extended crimp barrel and don't require a dedicated flag terminal crimping tool).

One could probably make a full-time job out of understanding the application guidelines for crimp terminals! I can report back when I receive the AMP crimper and new terminals. In the meantime, I'd still be interested in hearing any input and experiences from you all.

Abikos were female quick disconnects.

Crimp terminals are real pain in the butt to do properly.. specs are spread across dozen of pdf or not specified at all 🙈

[Benta]

I tried those connectors out 25 years ago. They were useless then and they're useless now, no matter which brand or crimp tool you use.
The idea/design is faulty from the start and no serious engineer would ever use them.

Functioning crimp connections use the "4-tab fold-in" design, like these:

Insulation is done with tailored sleeves or heat-shrink tubing.

[mzzj]

I tried those connectors out 25 years ago. They were useless then and they're useless now, no matter which brand or crimp tool you use.
The idea/design is faulty from the start and no serious engineer would ever use them.

Functioning crimp connections use the "4-tab fold-in" design, like these:

Insulation is done with tailored sleeves or heat-shrink tubing.

Bollocks. Proper combination has higher strenght than the cable itself.
Been there, measured on pull-out force tester..

[Yansi]

I second that I have never had any problems with the color plastic coded crimp terminals.  I have used both the rings, forks and fastons. Never had any issue. 

Even the whole power electronics lab in the university where I have studied runs on these style of crimp terminals on almost all test jigs.

And you can rest assured you are not going to pull the wire out of the crimp when properly crimped.

[Benta]

Bollocks. Proper combination has higher strenght than the cable itself.
Been there, measured on pull-out force tester..

Watch your language.

Apart from that, I've yet to see professionals using those "DIY-Supermarket" insulated connectors.
Automotive? Nope.
Industrial? Nope.
Consumer? Nope.
...

Please tell me in which professional equipment they're to be found.

[Monkeh]

"DIY-Supermarket" -> $400 crimp tool. Errr..

IME they're mostly seen in retrofit and small volume as they're less labour intensive and don't require you to remember to slip an extra shroud over the cable. Mass production does usually use discrete terminals and shrouds, presumably they're cheaper.

Proper matching of tool, crimp, and cable and insulation size results in perfectly acceptable crimps. Less proper matching can work well, can also backfire immensely. And apparently, Molex need a cluebat application.

[mzzj]

Bollocks. Proper combination has higher strenght than the cable itself.
Been there, measured on pull-out force tester..

Watch your language.

Apart from that, I've yet to see professionals using those "DIY-Supermarket" insulated connectors.
Automotive? Nope.
Industrial? Nope.
Consumer? Nope.
...

Please tell me in which professional equipment they're to be found.

Military? Aerospace? Does that count as professional?


Fold tab(F-crimp) connectors are for LOW COST mass production.

[iroc86]

Functioning crimp connections use the "4-tab fold-in" design...

I would tend to agree. I haven’t had the best luck with the “4-tab” terminals (probably wrong crimper), but I’ve historically used the non-insulated F-crimp Molex Krimptite terminal with separate heat shrinking. Partly because I have a strange attachment to my ancient Molex/ETC crimper , and partly because the joints are really reliable.

I haven’t started using the insulated terminals until relatively recently (see last paragraph below).

Proper combination has higher strenght than the cable itself.
Been there, measured on pull-out force tester..

And you can rest assured you are not going to pull the wire out of the crimp when properly crimped.

I also agree. Though hardly a scientific test, I tried pulling off each of those terminals in my original post. The smaller QD terminal slid right off, but I could absolutely not get the ring terminal to budge using pliers and pulling as hard as I could. Per Molex, the Insulkrimp terminals are rated for 50 pounds tensile strength with 14 AWG wire—it’s likely much greater in practice. I’ve gotta think that makes a secure electrical connection.

IME they're mostly seen in retrofit and small volume...

Military? Aerospace? Does that count as professional?

This is just one data point, but I work for a “you definitely know them” research institution and my group often builds custom electromechanical systems for data collection and measurement. Everything has to be approved by our electrical safety officers prior to leaving the R&D lab. We almost exclusively use insulated crimp terminals on these one-off projects, and I’ve never seen one rig rejected due to the type of crimp terminal.

Considering that insulated terminals are widely used in our specialized applications at work, I decided to give them another try with a proper controlled-force crimp tool. The tricky part seems to matching the terminal to the correct crimper—not all are created equal, even though they look awfully similar.

[WattsThat]

Measured a bunch of vintage Amp and T&B blue terminals, QD, ring and spades. All were 0.220 to 0.225.

The Amp terminals had matte blue bodies like the photo in reply #3, the T&B’s somewhat translucent blue, probably nylon.

All my red terminals measured all about 0.190.

Based on those diameters, I’d be crimping your blue QD’s in the red die.

Of course YMMV.

[Benta]

Fold tab(F-crimp) connectors are for LOW COST mass production.

Allow me to correct your statement:

Fold tab(F-crimp) connectors are for LOW COST, RELIABLE mass production (eg, think 40-year old cars).

[mikerj]

I tried those connectors out 25 years ago. They were useless then and they're useless now, no matter which brand or crimp tool you use.
The idea/design is faulty from the start and no serious engineer would ever use them.

Functioning crimp connections use the "4-tab fold-in" design, like these:

Insulation is done with tailored sleeves or heat-shrink tubing.

There are millions of these terminations in track side railway signalling equipment all over the world.  I spent several years working for a company building these racks, and sectioned test crimps and wire pull tests were performed daily for each tool used.

[iroc86]

Thanks for those measurements, WattsThat.

Here's a quick update with some AMP/TE insulated terminals and a different crimping tool. These are Pre-Insulated Diamond Grip (PIDG) quick disconnects. They're a bit larger than the Molex Insulkrimp and have a copper lined insulation sleeve, similar to the Molex Avikrimp. I've used about two dozen of these so far--they seem to make an extremely secure crimp. As shown below, the tabs form a symmetric F-crimp and the metal insulation sleeve bulges out around the insulation, gripping the insulation better than the plastic alone.

The PIDG terminals are definitely a step up from the cheaper insulated terminals, but I think the quality shows. I wouldn't hesitate to use these in place of non-insulated terminals with heat shrink tubing. Of course, finding a crimp tool with the proper geometry is also the other half of the coin!

[Benta]

I tried those connectors out 25 years ago. They were useless then and they're useless now, no matter which brand or crimp tool you use.
The idea/design is faulty from the start and no serious engineer would ever use them.

Functioning crimp connections use the "4-tab fold-in" design, like these:

Insulation is done with tailored sleeves or heat-shrink tubing.

There are millions of these terminations in track side railway signalling equipment all over the world.  I spent several years working for a company building these racks, and sectioned test crimps and wire pull tests were performed daily for each tool used.

I'm sure you're right. But that's a static installation with no mechanical stress.

[SilverSolder]

[...]  These are Pre-Insulated Diamond Grip (PIDG) quick disconnects. They're a bit larger than the Molex Insulkrimp and have a copper lined insulation sleeve, similar to the Molex Avikrimp.

[...]
 Of course, finding a crimp tool with the proper geometry is also the other half of the coin!

So, which crimping tool do you like for the PIDGs? 

[iroc86]

So, which crimping tool do you like for the PIDGs?

I'm using an older version of the TE 59824-1, which is one of the "approved" crimpers. The forming dies are shaped like a diamond and operate a little differently than the KNIPEX tool I posted earlier. I've included some stock photos below.

Last week, I reached out to KNIPEX to see if they have any input or recommended product lines for their crimping dies. They just wrote back today:

We do not have a Go/No-Go gauge for our crimping tools. We do not have a specific manufacturer of crimp terminals that work with our dies. What we can offer is that if the customer sends us the wire and terminals they are using, we can have our engineers in Germany test those to make sure the die provides the perfect crimp.

The direct testing service in Germany is pretty cool, and I suspect a lot of their industrial/production clients go that route. However, I'm disappointed that they can't provide some basic guidelines as to application--I mean, what criteria are they using to design the dies in the first place?

The KNIPEX crimp die for insulated terminals is not terribly expensive at about $100, but others can be quite a bit more costly. It's tough to rationalize that kind of investment when they don't provide gaging specifications to ensure crimp quality. That being said, I own a number of other dies for their Crimp System and have seen excellent performance with ferrules, butt splices, and those "4-tab" F-crimp terminals discussed earlier.

[wizard69]

I tried those connectors out 25 years ago. They were useless then and they're useless now, no matter which brand or crimp tool you use.
The idea/design is faulty from the start and no serious engineer would ever use them.

Functioning crimp connections use the "4-tab fold-in" design, like these:

Insulation is done with tailored sleeves or heat-shrink tubing.

Bollocks. Proper combination has higher strenght than the cable itself.
Been there, measured on pull-out force tester..

I'm with Bent on this one, this based on a long career in industry.   The crimps that even brand new crimpers, for insulated terminals, produce are terrible.If yu have to use crimp terminals you are far better off with non insulated ones and a crimper designed for them.

[mzzj]

I'm with Bent on this one, this based on a long career in industry.   The crimps that even brand new crimpers, for insulated terminals, produce are terrible.If yu have to use crimp terminals you are far better off with non insulated ones and a crimper designed for them.

Define  "terrible"
Sounds like you got either mismatched tool/terminal set or low quality terminals. No-name cheapos can be anything (or "budget line" brand names)
Same applies to fold-tab or F-crimp terminals..

I was curious how good the Abico terminals sold on local "auto store" are and tested the crimps with fishing scale and bucket of weights.
Crimped with the cheap knipex clones the pull-out force on 1.5 mm^2 wire exceeded the military standard requirement (50 lbs for 16 AWG)
https://www.cirris.com/learning-center/general-testing/special-topics/228-crimp-pull-testers-pullout-force-per-wire-size

OK, wire was slightly oversize (16 AWG vs 1.5 mm2) but still  ahead of the "commercial" standards.
AFAIK automotive USCAR-21 standard would satisfy with 170 N or ~38 lbs

[2N3055]

I have given up looking at the color codes a long time ago. I make a test crimp and if I can pull the wire out then I use the smaller opening.

This. Same here.

And Molex are assholes, with their 500000 USD custom crimp tools...
I suggest you change title. Knipex is at no fault here. It's Molex that is not standard.
I use Knipex and Pressmaster and they are both excellent.

[iroc86]

And Molex are assholes, with their 500000 USD custom crimp tools...
I suggest you change title. Knipex is at no fault here. It's Molex that is not standard.
I use Knipex and Pressmaster and they are both excellent.

Haha yes, I do question Molex's motives when they sell a single $500+ crimp tool that's designed to crimp one part number. That's what turned me on to TE/AMP and their PIDG stuff--slightly more expensive than Molex, but the tooling standardization is definitely worth something (especially in a DIY/hobbyist capacity where one cannot afford a dozen different crimp tools).

I updated the title per your suggestion to capture the other brands.

Out of curiosity, would you mind sharing the KNIPEX tooling you're using for crimping?

[mzzj]

18 AWG wire+ chinesium crimpers + Abiko terminals:
https://imgur.com/a/JRrsZQS

Crimping action is pretty stiff and crimp anvils wont reach each other. Looks like even the wire insulation stripped off.

[2N3055]

KNIPEX 97 52 36 for insulated terminals. For others I use Pressmaster modular..

[Gregg]

I see no reason not to use the indent type crimpers on the plastic sleeved terminals.  I mainly use the Thomas & Betts or Klein for the red and blue ones and a bigger dimple crimp on a pair of Klein pliers for the yellow.  For larger terminals, hex crimps are the best I’ve found.
The double half-moon type crimpers for the plastic sleeved terminals are a crapshoot as far as them passing the tug test.
https://www.alliedelec.com/product/thomas-betts/wt111m/70039935/
https://www.amazon.com/Insulated-Non-Insulated-Klein-Tools-1005/dp/B0006M6Y5M
https://www.kleintools.com/catalog/high-leverage-connector-crimping/linemans-pliers-crimping-9-inch

[iroc86]

mzzj, by the looks of those crimps, I bet my KNIPEX dies would work with these PIDG double-walled terminals. They measure about 5.7 mm on the OD, just a hair smaller than the 5.8 mm Abikos you described in Post #5. It looks like you're still getting that secure squashed/bulging effect on the insulation, even though the Abiko dies look quite a bit different than my TE/AMP tool.

2N3055, thanks for sharing the KNIPEX tool you're using. I bet the geometry is identical to my Crimp System. What brand of terminals do you prefer?

Gregg, do you have any issues with the insulation sleeving breaking with the dimple crimpers?

Interesting discussion on the dimple-type crimpers. I have the KNIPEX 97 49 14 dies (shown below) which are intended for non-insulated tubular terminals per DIN 46234 and 46235. These do not produce an F-crimp. I've used them on Molex Krimptite with success, but I think they might work best with brazed seam terminals due to the crimping forces involved (no splitting of the seam). Panduit, however, notes in their application guides that you can use either type of seam with their tool, just align the seam opposite the indentor. Any real world experience on that one?

[Gregg]

I haven’t had any problems with dimple crimps removing the plastic sleeves on reasonable quality terminals.  Sometimes the plastic will become a little loose with the barrel to wire connection very secure; the plastic sleeve really doesn’t do much unless there are multiple connections close enough that they might short without it.  Mainly it covers up strands of wire that a lazy tech didn’t get into the crimp barrel and makes an installation “look pretty”.
I was on a big job years ago installing hundreds of control wires and a co-worker had the company buy a couple of the expensive double half-moon ratchet crimpers.  I used my own crimpers and was told they weren’t “certified for the terminals” being used.  I then grabbed a bunch of his crimped terminals and gave them the tug test – a quarter of them pulled right off.  These were the red Thomas & Betts terminals 16 to 22 ga rated being used with 20 ga stranded TFFN wire and a Thomas & Betts crimper.

[mikerj]

I tried those connectors out 25 years ago. They were useless then and they're useless now, no matter which brand or crimp tool you use.
The idea/design is faulty from the start and no serious engineer would ever use them.

Functioning crimp connections use the "4-tab fold-in" design, like these:

Insulation is done with tailored sleeves or heat-shrink tubing.

There are millions of these terminations in track side railway signalling equipment all over the world.  I spent several years working for a company building these racks, and sectioned test crimps and wire pull tests were performed daily for each tool used.

I'm sure you're right. But that's a static installation with no mechanical stress.

Track-side equipment is subject to fairly heavy vibration.  It's also a safety critical application, if these terminations were as bad as you say then they wouldn't be used.

[Doctorandus_P]

There is also a lot of quality difference in the crimp connectors themself.
The cheap ones are just made out of stamped sheet and the tube for the wire is open.
On high quality crimp connectors there is a piece of tubing between the stamped connector and the plastic sleeve.

Apart from that.
The whole concept is inherently flawed. Crimping metal connectors through soft plastic is a shaky recipy.
It can be made to work, but to make it work well you will need tight control of tolerances and materials of both pliers and the connectors themself.

[iroc86]

It can be made to work, but to make it work well you will need tight control of tolerances and materials of both pliers and the connectors themself.

Based on what I've seen and learned in this thread, that really does sound like the clincher. There's definitely some overlap between manufacturer's crimping dies where the insulated terminals can be made to work, but if I were working on any mission-critical application, pull and endurance tests are probably the only way to be sure the crimp is acceptable.

Yesterday I was checking out a friend's private airplane. Lo and behold, there were double-walled insulated crimp terminals all over the place. I doubt the (U.S.) Federal Aviation Administration would sign off on the use of these terminals if they weren't reliable, especially considering the prevalence of required backup systems and fail-safes in the aviation industry.