Matt takes delivery of an MDPC-X “CTX3” crimp tool

It was a dreary November morning. As I sat idly on the sofa watching breakfast television, the sound of hoofs is heard out the window. I pulled the curtain to one side. A divine light immediately streamed into the room. Imagine my surprise, to see a long-white bearded courier, seated upon a Unicorn, with a small brown box under one arm.

I rushed to the door. He dismounts, and to the sound of an ethereal wave, hands me the box, with a big smile.

Yes, my MDPC-X CTX3 has finally arrived. I previously had quite a bit of fun commenting on it in this post but the hype surrounding this tool is of such magnitude, that I wasn’t happy to just look at the pictures of it. I had to have it.

First things first

In my previous post, I observed that it looked extremely similar to an IWISS SN-28B, to the extent that it appears to be a straight-out re-badge. Now that I have both of them here, let’s compare:

MDPC-X CTX3 and its apparent progenitor, the IWISS SN-28B. The one I received looks a little different to the marketing images I’ve seen, not having the shiny Torx screws, instead they’re more like that of the SN-28B, other than that, the same tool.

First of all – the frames. Aside from the colour of the circlips, handles and some differences in markings, they’re identical. It would be extraordinary if it were to be demonstrated that the CTX3 frame wasn’t manufactured by IWISS, let alone outside of China.

There are however clearly some minor differences in the die. The first thing that jumps out at me is that the anvils are slightly different.

SN-28B and CTX3 insulation anvils stacked on top of each other for comparison

Interesting. The insulation anvil from the CTX3 looks like it was from an SN-28B originally, but a little bit has been milled off the larger two for some reason. Perhaps this modification was made in Germany?

SN-28B and CTX3 conductor anvils stacked on top of each other

We have this same modification on the conductor anvil. I wonder why? The conductor die in the SN-28B tends to be too loose as it was, allowing wires to easily be pulled from the contact, where the manufacturer tools do not. Milling more off it would make this situation even worse. I’d stick with the SN-28B here if it were my money.

CTX3 and SN-28B insulation crimpers side by side

These are identical, except on the CTX3 the markings have been ground off, but not entirely. They’re sort-of still visible in the above shot. It looks like this was done by a butter-fingered individual, as it’s clearly been dropped on one corner in the process.

CTX3 and SN-28B conductor crimpers side by side


Detailed description of changes from SN-28B

Aside from cosmetic changes to the frame, the remaining changes are removal of material from the anvils, as follows:

  • 0.4mm from the large insulation anvil with a 3mm end mill
  • 0.2mm from the medium insulation anvil with a 2.5mm end mill
  • 0.1mm the large conductor anvil with a 3mm end mill
  • 0.1mm from the medium conductor anvil with a 2.5mm end mill

This must be the basis “CNC” claim of this tool. A change like this surely would be done in a CNC milling machine, but it is a very small change to make. Far from 5 axis, 3 axis, whatever – it’s just a single axis adjustment.

Re-labelling of dies

The biggest difference is in the usage of the tool. MDPC-X have re-labelled the dies, i.e. on the SN-28B, AWG 18 cable is stipulated to be used in the larger die, however on the CTX3, it’s stated that the medium die is to be used, and so on. Funnily enough, something that I used to do anyway when I was crimping these contacts with an SN-28B.

This means the CTX3 gets tighter crimps than the SN-28B would have done, if one were following the instructions, however if we do the same in the SN-28B, we get a better crimp on the conductor because no material has been removed from the conductor anvil, unfortunately doing so may create fatigue points on the the insulation crimp, hence the need to remove material from the insulation anvil.

Making your own CTX3

It appears it’d be quite easy to make the CTX3, by starting with an SN-28B, and simply filing down the medium insulation anvil with 2.5mm needle file, and the large insulation anvil with a 3mm needle file. I’d advise leaving the conductor anvils alone, as this’ll leave the result closer to Molex’s specifications.

Standards? and comparison with other tools

This tool is said to be designed according to the “MLX guidelines”. I was unable to find any document or standard with this name. I’ll have to assume that it exists, and that MLX is shorthand for Molex, and guidelines referring to how these contacts are meant to be crimped according to the manufacturer.

The problem with this assumption is that it’s intended to crimp contacts which were originally designed by other companies, that Molex have never produced. Secondly, this tool is modified for crimping sleeved cable, which is not something any manufacturer original tool can, or would ever need to do. We’re already in murky waters here.

Further reading

I’ve written up a new page, where the CTX3 crimps are compared to the SN-28B, and also all of the manufacturer originals for PC modding. I’ve also tried to infer what may have been written in those “MLX guidelines”.

Lots of tools, all on wood. Unfortunately however, it’s just my grotty floor. This write-up isn’t quite as exciting as MDPC’s marketing materials, but we’ll get the chance to see how all the relevant contacts are meant to be crimped according to their designers.

3 Taiwanese companies, 3 German companies

A couple of readers have pointed out this statement on MDPC-X’s website (quoted):

The MD-CTX3 crimping tool is the result of 6 involved companies in Taiwan and Germany: 3 different companies in Taiwan are responsible for the base, 3 companies in Germany are responsible for the end product.

IWISS themselves are based in Liushi, Wenzhou, China, and do not have any presence in Taiwan that I could find. Could it be that there’s a company in Taiwan who makes an identical tool who I’m unaware of? It would be interesting to know what the basis of this claim is.

As for the three German companies, this is probably true. I can see three things that’d need to be done in Germany:

  • Milling of the original SN-28B anvils
  • Laser etching of MDPC-X’s markings (I’d guess the tools are supplied unmarked from IWISS).
  • Packaging


The MDPC-X CTX3 is mostly an IWISS SN-28B, a definitively Chinese manufactured tool. Given its price point, and the price of the tool it appears to have been derived from, I would be astonished if it were to be proven that this tool was made in Germany, as is stated by the marketer, and at the same time, questioning why. So what’s German about it then? Possibly a few minutes in a milling machine in Germany, and apparently the people selling it.

My message to them: There was no need to spin a doubtful narrative around this tool. It is slightly different from the SN-28B, as it may need to be for its intended use-case. Milling down those anvils is extra effort, and therefore extra cost, so understandably will cost a bit more, and, there has to be a bit of profit for the marketer for going to the trouble. Why not just say it? I’d not have any problem with that.

Without crimping anything with it, unfortunately it looks that its performance on the most important part – the conductor, will actually be inferior to the SN-28B, for the price, not something I’m pleased to find.

Posted in Crimp tools and connectors

35 thoughts on “Matt takes delivery of an MDPC-X “CTX3” crimp tool

  1. Such a good write up, I really enjoy reading your posts!
    Especially regarding crimpers and terminals! And even more with them based around pc cable modding!

    I am amazed that you can clearly see the wire guage markings on the insulation crimpers have been grounded off. I checked my pair and I cannot see the guage markings on mine so I think you were “lucky” to receive a pair that have it slightly visible to further prove they were in a previous life a SN-28B.

    All the other modifications you explained I can confirm are the same in my pair of the CTX3 crimpers.

    I am REALLY looking forward to your next page comparing the CTX3 to the SN-28B and the original manufacturer crimpers. That will definitely be interesting!

    1. Looking at it further, one thing I initially missed is that the dies have been “re-graded” on the CTX3, hence why the markings have been ground off. When we consider that, the changes start to make a bit more sense. I’ve updated the article to reflect this.

  2. Finally 😀
    I was waiting for this for a week or so
    I’ve talked to people in the PC sleeving community and they said that the CTX3 is, indeed, superior to the SN-28B. To be frank, those are not experts in crimping by any means but those tiny changes could make the difference! I personally haven’t bought either of them so I am really looking foward to your crimp results (especially the comparisons between the SN-28B, the CTX3 and the SN-025).
    Thank you for your work here!

    1. Do you know if they are referring to IWISS SN-28B’s or “no-name” SN-28B’s ? there’s a big difference – the no-name ones have moulded dies and generally do a pretty terrible job.

      Aside from that, the story of the CTX3 so far, is that it’s a mixture of bullshit, and some actual genuine improvements over the IWISS SN-28B. There’s quite a bit I’m going to have to cover and examine so be patient 😉

      1. Well both. I’ve talked to people who use the one with the black moulded dies and the silver ones by IWISS. Both said that the CTX3 always gives super good results and it is their go-to. I am still quite torn. On one hand, its an overpriced SN-28B but on the other it is 50 bucks, just like the Sn-28B AND the Sn-025. I am going to sleeve quite a few cables and the CTX3 is able to do just that (Fan pins, Dupont for front panel connectors and the Mini Fit Jr. ones) so why should I use 2 tools for the same amount of money?

        I will do my purchase around christmas anyway so I don’t mind informing myself for a longer while. Thats why I am really looking forward to your reviews, you seem to know quite a bit 😉

        1. Which wire sizes are most common in the sleeved world? I assume it’s AWG 18?

          From my testing so far, there isn’t likely to be a definitive best between IWISS SN-28B and CTX3. SN-28B wins for the wire crimp, and CTX3 wins for the insulation crimp (for Mini-Fit Jr, I doubt it’s used for much else).

          It would be possible to create an ideal tool by mixing the anvils from each, or just filing down only the insulation anvil in the SN-28B, but this is more hassle or expense.

          1. 16 awg or 18 awg for cables that use the mini fit Jr terminals. (Some use 16awg as it gives a “fuller” look with the sleeve)

            18 awg for cables that use the commercial mate-n-Lok and sata power terminals.

            22awg for cables that use the “dupont” style terminals and the KK 254 terminals.

          2. 22 AWG for KK and PV types, wow, that is interesting. That would be quite an unusual practice in the world of professional termination. Generally mass produced PC hardware uses AWG 28 for these connectors.

            The KK tool doesn’t even go that large, M20 doesn’t either, PV does but you need a different, uncommon tool for it.

          3. I’ve seen people put 18 AWG wire on PC Case fan cables… (no idea how that worked) I will be using the 17 AWG Wire by MDPC (not for the fans tho).
            People generally use the cables that are available on the Modding Websites (MDPC, Titan Rig, Mainframe Customs etc.) so it is mostly 15-18 AWG for the PSU cables and around 23 AWG for PC case fans and the front panel headers (dupont).

    2. Personally, I get my terminals and wire from the electronics stores, like Digikey etc as you know you’re 100% getting authentic terminals and buying the relevant guage equipment wire from them in the 100m reels is ALOT cheaper than buying from a dedicated pc sleeving store.

      However regarding the use of 22awg wire being used for the KK terminals and dupont style terminals, I can only assume is because they give a more fuller look than 28awg? Possibly?

      However, I find it not logical that the KK an dupont style terminals are speced for 22awg but the original crimpers are not. Is this a common thing in the crimping world out of interest? Or did I interpret what you said incorrectly ?

      1. There are applications for 22 AWG dupont style terminals such as R/C servos for which 28 AWG lead would be inadequate. I’ve even seen some servos with a 20 AWG lead on them (Mini-PV comes in an 18-20 AWG version and there is an official crimper for that) I’m sure there are others uses too where you want a 0.1″ connector but the thing it’s connected to pulls to much power for a 28 AWG wire.

  3. The MD-CTX3 crimping tool is the result of 6 involved companies in Taiwan and Germany: 3 different companies in Taiwan are responsible for the base, 3 companies in Germany are responsible for the end product.

  4. Definitely love all your articles, especiallly crimpers and terminals… 😉
    Perhaps you could also review on cable strippers,.. I know It seems not too important, but I can feel your power in writing.. So hopefully in short future..

  5. So I got my IWISS SN-28B now and tried the middle die as you said. Indeed the wire crimp is MUCH stronger (as you’d expect), but the insulation crimp (18 AWG wire, 2,1mm OD) is VERY fatigued. The wings almost break off by themselves because the die is simply to small. I am actually thinking about getting the CTX3 now but not for this price difference. (20€ vs 52€).
    I also tried out the JX-1601 Crimper and it *works*. It is much to lose but I actually think it would work for wires that don’t experience high loads. I used the wrong die though, because I used the 1mm² die on 18 AWG wire (~0,86mm²) so that is expected. I will retry everything on 0,75mm² wire (2,0mm OD). This topic is, for some reason, very interesting and intriguing 😀

    1. > This topic is, for some reason, very interesting and intriguing

      Be sure to set yourself a limit. Don’t end up like me with a collection with 80+ crimp tools 😉

  6. I was looking around iwiss and I saw the SN-48B, wouldn’t this be a better crimper for 16 or 18awg wire compared to the sn-28b?

        1. Hmm. Reading about the 48B and 58B ( I actually ordered the 58B to try it out ), it is what people use for 16 AWG wire. It also has a “20-18 AWG” slot, seems like a better choice than the 28B then. I might just order the replacement 48B die off of aliexpress straight from IWISS to try out (IF the 58B does a bad job).
          I wonder if the CTX³ might just be a 48B (not 28B), this would make sense because the 48B uses the middle slot for 18 AWG and the biggest slot for 16 AWG.

          1. After a few months of reading, crimping and sleeving I sadly have to admit that the SN-58B is absolutely bad for 1,5mm² wire. It works perfectly for 0,25mm², 0,5mm² and 1mm² wire but completely stinks on anything that requires the biggest crimper. I will obviously keep it and keep using it for pc fans, LED wires, dupont etc. but have to find something bigger for anything bigger than 1mm² (probably the 48B?).

            How is your SN-025 working? I might just buy that at this point but I don’t want any more (wasted) crimpers in my collection.
            The IWS-2820m and 2420m seem to be on par with their Engineer PA-09/PA-20 counterparts but the ratcheting crimpers seem to always get the upper hand in terms of strengh and quality of the crimp connections.


          2. Hozan P-707 (or the IWISS clone of it – IWS-1442L) is the only decent option for big stuff that I know of.

  7. I got in contact with some guys at IWISS and gave my feedback on how to improve their products. I absolutely don’t claim to be an expert here but I have done some research and thought I’d let them know.
    I informed them that their tools are extremely popular among PC modders (ctx3 included) and that most of us use the tools for Molex terminals (or knock-offs) and that they should look into copying the asymmetrical punch of the original tool and the rounded anvils of the CTX3.

    Moreover I said that the die used for small cables (24’ish AWG) should have a round punch because it is mostly used for DuPont knock-offs (I read your articles 😀 ) and knock-off KK.254
    Fan terminals – and those work best with a round punch.

    Last but not least I wrote that they should use the SN-2549 as a base for these changes because it also has the 28 AWG die of the SN-01BM, which enables modders to use it for picoblade and JST PH 2.0 and so forth.

    I don’t want to get my hopes up too soon because it is unrealistic that they just accept feedback of a random guy who they talked to a few times from the other side of the planet but as a university student I have a lot of spare time right now and this “project” is a lot of fun, especially if I could see actual changes in a product that people can/will/should(?) buy.
    They responded that they actually plan to make a tool that is close to what I suggested and will contact me as soon as they know something new.

    If you were to be asked what changes you would like to see in a budget crimping tool? I know you have a metric cr*p ton of experience with original tools so I thought I’d ask you 😀

    I guess they should work on getting tighter conductor crimps as that is the most important part but as they already made steps into the right direction (SN-025) they could just try to make a budget Molex Mini-Fit Jr. crimper that becomes the new go-to for all makers.

    If you can think of any additions or critique to my ideas let me know!

    1. > I got in contact with some guys at IWISS and gave my feedback on how to improve their products.
      Good. Hopefully they’ll listen. I’ve admittedly not bothered to do this having had very little success to get Chinese manufacturers to change tack on previous efforts. It can be hear feedback over the sound of banking large profits churning out easy to manufacture rubbish.

      > If you were to be asked what changes you would like to see in a budget crimping tool? I know you have a metric cr*p ton of experience with original tools so I thought I’d ask you
      Correct on the metric crap tonne, I certainly prefer those over the imperial variety. Experience. Nah. I’m just an itty bitty buying tools off eBay and putting up pictures. Hopefully that’ll help people make better purchasing decisions, and set expectations for third party tool manufacturers.

      My feedback to Chinese manufacturers is: “FFS. Stop churning out crap tools. Buy a Z20-320, 63811-8200 and 63819-0900 and make something that does what they do”.

      1. I’d already be alright with a tool that doesn’t break the bank but delivers crimps that don’t destroy my components or devices. I sadly have to agree that – for them – investing money into R&D for a better product is not in their interest, they want to make money.

        They did make efforts to deliver something new in form of the SN-025 though, it has a machined jaw and is not produced as often as other SN-series *tools* are.

        If they really won’t bother with anything else, which I wouldn’t judge them for, I might just take matters into my own hands and machine the jaw myself, just like the MDPC guy (but better).

        Luckily my University has ultra high precision machines and I happen to know a few people with access there. It would be cooler being able to buy it.

        1. That is certainly something MDPC could have done that would have been impressive: Buy IWISS handles but sell them with an entirely new die.

          Designing and machining a new die would be quite an interesting project.

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