Molex KK Crimp Tool Recommendations.

Hey guys,

I have been using the Molex KK 2.54mm (0.1") and 3.96mm (0.156") crimp pins and headers for most of my project for the past few years and have had good luck.

I have the entry level crimp tool, which is just a pair of pliers made by Waldom that has dimples in the jaws to crimp the pins...

https://www.jameco.com/z/W-HT-1921-Waldom-Electronics-Tool-Crimping-Hand-Molex-for-062-Inch-And-093-Inch-Contacts_227491.html

this is fine for a crimp or two here and there and one thing that is good about this tool is that you can use it for both the 2.54mm and the 3.96mm pins. My biggest issues with the Waldom pliers is the inconsistency - about half the time the body of the crimp pin gets bent affecting the fit of the pin in the header.

I have a big project coming up, one with easily a thousand crimps, and want a proper crimp tool.

I'm looking for:
a. ideally a ratchet one (like the EDAC pin tools)
b. one that would work for both the 2.54mm and 3.96mm pins
c. one that will work from 26GA to 18GA

I have searched back and all the threads seem to be about getting the cheapest tool...

But Im willing to pay the money if the crimps will be faster and more consistent.

I am looking around and it seems there are a lot of options - I was wondering what you guys are using?

thanks everyone,
Timothy

You are better to solder those pins and just use a standard crimper and pliers to get the top bent in so it fits the header. Those pins are unreliable when just crimped. The solder makes them a whole lot more reliable and its easy to do.

I kinda like the MTA connectors... MTA100,156... 

https://www.te.com/usa-en/products/connectors/pcb-connectors/intersection/mta-100-mta-156-connectors.html?tab=pgp-story

they do have a crimp tool with different heads...and there's a hand tool.... Here's a video showing the hand tool....

https://www.youtube.com/watch?v=uRiZFxZz_7Y

I use one of these https://www.rapidonline.com/rvfm-ht-225d-ratchet-action-crimp-tool-ht225d-85-0262  Sadly like most things tool & electronic wisse it is now more than twice the price I bought mine for ......

I have to disagree with Doug re them being unreliable.  When I use this tool & they are crimped so the insulation of the wire is crimped in the right place in the pin I have found them to be very reliable.  I never find the need to solder them.  The issue arises if the wrong tool is used & they aren't crimped correctly.

+1 for reliability when crimping is done right...

Jakob E.

gyraf said:

+1 for reliability when crimping is done right...

Jakob E.

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+2

Ian

Rob Flinn said:

I have to disagree with Doug re them being unreliable.  When I use this tool & they are crimped so the insulation of the wire is crimped in the right place in the pin I have found them to be very reliable.  I never find the need to solder them.  The issue arises if the wrong tool is used & they aren't crimped correctly.

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+1 What he said. I have designed loads of these into serious industrial analysis instrumentation kit with high reliability.
Maybe it's a Sussex thing

Here you go, a typical crimped failure. The current on this connector is at least ten times higher than the designer thought it was.

Nope, that's not a crimp fail, but from overloading a connector. Maybe you are bashing Molex's, not crimping as such?

Come to think of it: Maybe you're trolling?

Jakob E.

radardoug said:

Here you go, a typical crimped failure. The current on this connector is at least ten times higher than the designer thought it was.

Click to expand...

Errr...you are saying that the connector was way overloaded ? Guess that would explain the great big heat damaged area on the housing

No Gyraf, not trolling. Consider the way a rectifier system operates, diodes into a big cap. The cap charges up, then get partially discharged by the load current. The rectifier only conducts when it gets above the cap voltage. In the remaining part of the a.c. cycle where the voltage is higher than what is on the cap,  the diode will conduct. So for a very short period of the mains waveform, you have to supply all the power required by the circuit. So if its conducting 10% of the time, and the output current is 500 mA, then the peak current is 5 amps, roughly speaking. What happens is you get a slightly dodgy crimp, and it heats up, oxidising the wire and the terminal. The longer this goes on, the worse it gets. This fault is very common in Eventide 910 and 949 harmonisers and other equipment.

radardoug said:

... This fault is very common in Eventide 910 and 949 harmonisers and other equipment.

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But this is a design failure / production error of the Equipment, not of Molex.
There is far more equipment using Molex Crimp Connectors without any problems.
Think of all those Computer PSUs ...

[silent:arts] said:

But this is a design failure / production error of the Equipment, not of Molex.
There is far more equipment using Molex Crimp Connectors without any problems.
Think of all those Computer PSUs ...

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+1. Obviously there is a potential problem if you have a dodgy crimp ☺.
fwiw for power connections I spec the Molex SPOX type which have a four face connection on the crimp. There is a degree of comparability with standard KK headers - those Molex families, part numbers and options get kind of complicated.

[silent:arts] said:

But this is a design failure / production error of the Equipment, not of Molex.
There is far more equipment using Molex Crimp Connectors without any problems.
Think of all those Computer PSUs ...

Click to expand...

Yes its a design failure. But they happen. Molex used within its ratings is fine. I agree. But used in this manner it is not within its ratings. And there are lots of devices out there like this.

Hey everyone - thanks for all the replies - sorry for not getting back here sooner - this thread took a bit of a turn.

I am glad to see you guys also having good luck with these - I, myself, have never had to solder any of these type connectors in addition to the crimp - no matter how bad the crimp is - I am always careful of the strip dimensions which i find to be the most critical part of using these.

In the past I have been known to solder a crimped ring terminal on small gauge wire, but I read in one of the NASA Standards Papers that soldering the crimp actually makes it weaker and less long term stable because it makes the wire end more brittle - so while it may be an easy short term "fix" for a poorly crimped pin/wire - it could also be the cause of the faults and failures down the road.

so back to the tools:

Rob - I was able to find several retailers on this side of the pond that sell that model of Crimp Tool - this look right?
https://www.ebay.com/itm/HT-225D-Full-Cycle-Ratchet-Crimping-Tool-with-interchangeable-die-set-HT-225D/263232918507?hash=item3d49e793eb:g:x80AAOSwynRZy-Si:sc:USPSPriority!12919!US!-1

Here is my concern, I had a studio mate that  had one of the early Paladin crimp tools for the EDAC/ELCO pins and it was a great, high quality tool - When I was ready to buy one of my own and stop borrowing his - I tried to by the same tool - but Paladin had been bought by Greenlee (which seemed like no big deal, I have several Greenlee draw punches that are top of the line...) Well needless to say, I wound up having to get mine overnighted to me on a job, and then 2 replacements sent (both while still on location at a job, both failed immediately)  and I finally wound up having to spring for the proper EDAC Crimp tool and overnight shipping - which so far has performed flawlessly.

so circling back to the original question - looking at these:

https://www.molex.com/molex/products/datasheet.jsp?part=active/0638118200_APPLICATION_TOOLIN.xml&part=active/0008500114_CRIMP_TERMINALS.xml

and

https://www.molex.com/molex/products/datasheet.jsp?part=active/0638117400_APPLICATION_TOOLIN.xml&part=active/0008500108_CRIMP_TERMINALS.xml

is there any reason to spring for the more expensive tools vs the one Rob posted?
I see that the old Molex models had replaceable die's - thats nice...
Are these off brand tools going to fail at the worst moment?

Jakob? Ian? Newmarket? - what do you guys use?

mutterd said:

Jakob? Ian? Newmarket? - what do you guys use?

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I have one of the low cost types from Rapid. I bought it maybe 10 years ago and it has never failed me. I have had bad crimps but they were all operator error and not the fault of the tool.

But if I was going to be doing very large numbers of crimps that were mission critical I would spring for the proper Molex tool.

Cheers

Ian

ruffrecords said:

I have one of the low cost types from Rapid. I bought it maybe 10 years ago and it has never failed me. I have had bad crimps but they were all operator error and not the fault of the tool.

But if I was going to be doing very large numbers of crimps that were mission critical I would spring for the proper Molex tool.

Cheers

Ian

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I've been using mne for well over 10 years.  Never had any problems.  I don't think I would spring for an expensive one if I had 1000's to do.  I have a bunch of expensive edac, DL, Dsub crimp tools , & I have also used an original Molex crimp too.  With the DL & Dsub crimp tools the expensive one just work better & in my view are worth the money (although I got mine second hand off ebay for £30-40 each).  But comparing my cheapo molex tool to a proper Molex branded crimp tool I wasn't noticing much didfference

IIRC I posted the tools I use on another similar thread a while ago - Doug was in that one too claiming that the Molex connectors were too unreliable ! -. Anyway they are MOLEX brand 'pistol ratchet' type - I don't have the time to get the numbers right now - but I think I found out that they are now discontinued. Not sure what hand tooling Molex now supply - might need to look at it since the ratchets are now not quite working properly on the 'return'.
For high volume stuff (100s to 1000s) I'd use a local wiring company that has semi automated tooling - strips wires to correct lengths the press does the crimping. Nice.

And yes - soldering introduces a weakness in that there is a brittle point in the wire / crimp interface.

Newmarket said:

And yes - soldering introduces a weakness in that there is a brittle point in the wire / crimp interface.

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+ 1...........  must be a Sussex thing .....  I also never solder wires before putting them in screw secured terminals.    That makes them very unreliable.