JST Crimpers


I have a question regarding two electrical connector crimpers that Pololu offers. Both claim to crimp JST connectors, but they only specifically mention the RCY series. The links to these crimpers are:


JST offers many different series/connector types. In my electronics project, I am using the JST PHD and PUD series connectors/contacts:

http://www.jst-mfg.com/product/pdf/eng/ePA-F.pdf (page 5)
http://www.jst-mfg.com/product/pdf/eng/ePUD.pdf (page 2)

So the question is: will either of these crimpers work with the two contacts that I am using in my project? In looking at the datasheets for the three series types, I’m skeptical, but at ~$500 for a single set of factory crimpers from JST, I’m willing to try any reasonable alternative.



The specific crimp pins we have listed on the crimp tools’ product pages are the pins we have tested and know to work. We do not know how well our crimp tools will work with other pins and have not tested other JST crimp pins. If you decide to try our crimp tool, we would be interested in hearing how they work with those pins.

- Grant

Hi Grant-

Ok thank you for the feedback. I was expecting this answer, thinking that if y’all had tried to use either of these crimpers on the JST contacts that I’m using in my project, you would have advertised as much.

I’ll buy a pair tonight and give them a try whenever they arrive. I’m desperate to find an alternative to the $500+ factory JST crimpers, which I would need two of (one for each of the contacts in the two series that I use) which means the total would be in excess of a thousand dollars…for two hand-held crimpers!

I’ll report back with my findings. I plan on verifying my conclusions with the local assembly house who manufacture and build my boards. I plan on contracting with them to assemble the cabling anyway, and since they do that kind of thing on a daily basis, their opinion as to how well these crimpers work with the PUD and PHD contacts seems even more valuable.



The wider crimpers don’t work for either the PA§ series nor the PUD series contacts. In looking at the datasheet for the RCY series for which these crimpers are advertised, I noticed that the RCY series is a wire-to-wire connector whereas the PA§ and PUD series are both wire-to-board connectors. I also noticed that the RCY series has an appreciably larger tab spacing that would allow the wider crimpers to work, whereas the two series that I am using don’t.

Disappointing. So I dunno, not sure what to do next. I will think about it over the weekend. I’m tempted to try the narrower crimpers, but without any data on just how wide/narrow those cast areas are, I could buy another pair of crimpers that I wouldn’t be able to use. I’ve already got two of those. :confused:

So we’ll see. Hope this helps someone in the future.

Thanks for letting us know what you found. The crimping area on the die for the crimp tool with the thinner die measures about 4mm wide.

- Grant

Hi Grant-

Ok thanks. That’s good information to know, perhaps y’all should consider adding that to the description of the crimpers. I have decided to keep the wider crimpers because I am considering using the JST RE series connectors; the RE connectors are also wire-to-board connectors, but they have a wider tab area that is similar to the wire-to-wire connectors, so we’ll see. They might work. I’ll post that result. Finally, I’ve decided to purchase the smaller width crimpers to see if those will work with the PHD and PUD contacts. Based on the 4mm number you gave, it might work. I’ll report on that too.

Thanks again.

I am glad you are still able to make use of that crimping tool. I hope the other crimp tool works for you.

- Grant

Hi Grant-

Thank you for the continued replies. Let me be clear though: I am not certain yet whether or not the first pair of crimpers (the wider variant) will be of any use to me. I think they will work with the JST RE series, but I haven’t verified that yet. I am ordering some RE series hardware and will test them out when that arrives. I’ll then update the thread and let you know if they work with this JST RE series stuff.

That said, I do have some good news. The smaller-width crimpers do indeed work with both the JST PUD and PHD contacts. The only caveat is that they must be crimped using the rearmost die (this crimper has two dies). The front die leaves the crimping tabs too wide and so the contact won’t slide into the housing. However the rearmost die has a more convex shape to the crimping tabs and the result is a good fitting crimp that enables the contacts to slide into the housings for both PUD and PHD easily and correctly. I’ll verify this with my local assembly house soon, but really there’s no denying it. This type of thing either works or it doesn’t. And this does. Therefore y’all (Pololu) can add this to your description of the smaller-width crimpers if you want. I could even put together a video illustrating the result if it’d help.

The other item that might help others in the future is to know the width of the dies in these crimpers. That information helps because you can then look at the datasheet for the contact you are considering using the crimping tool on to make an educated first guess regarding the likelihood that they’ll crimp that contact correctly. I took measurements of both of them tonight with a good quality micrometer.

smaller-width crimper: 0.158" == 4.0132 mm
wider-width crimper: 0.276" == 7.0104 mm

Again, I will let you know what I learn regarding the RE series connectors and the wider-width crimpers.

Hope this helps,


One quick note. In the beginning posts I mentioned that I am using the JST PA§ connectors on my board. That is correct. However for whatever reason this style of connector uses the PHD series contacts, which is what I stated in my previous post. This can be seen on both page 2 and 5 of the PA series connector datasheet as given in the first post in the thread.


Thanks for letting us know what you found. I am sure some of our other customers will find your experiences with the crimp tools helpful.

- Grant


The JST RE series connector hardware arrived today. So I played around with it tonight. As much as I wanted for the larger set of crimpers to work on these contacts, they just didn’t. I tried a few times to make sure, but the crimp tabs were just too big to fit into the housings. Out of curiosity I tried the smaller crimpers to see what they’d do. And wouldn’t ya know it? The rear die on the smaller crimper worked just fine. It crimped the crimping tabs tightly enough that the contact would slide easily and correctly into the housing. Therefore unfortunately the larger crimpers are of no use to me in this project.

But y’all can advertise that the smaller crimpers do indeed work with the RE series wire-to-board hardware. Furthermore, if these crimpers will work with the RE series then they will also work with the RF series because it is identical to the RE series WRT the contacts. Specifically, both series are wire-to-board connectors and both use the same contacts. The only difference between them is that the RE series is single-row only whereas the RF series is two-row only. Again, the contacts remain the same between them.

So that’s my report. Hope it’s helpful.


Thanks again for letting us know what you found.

- Grant