Glarks SN-28B Terminal Professional Pin Crimping Tool for 2.54mm 3.96mm 28-18AWG 0.1-1.0mm2

Used properly this tool works great. I purchased this tool to make some 2.54mm Dupont cables. It is not a strait forward process with such small connectors, I looked at various tools listed of the SN-28B model (which is the proper tool for 2.54mm Dupont connectors), and all appear practically identical with very mixed reviews. These connectors are designed for a machine to hold onto that back strip that you break the connector off of, and since you take it off to do the connections with a manual tool like this, it gets rater awkward. Based on what the connector specs are, you only strip 3mm of insulation. While I have seen various uses of a "multistep crimp" approach where you do a partial crimp to get the shape easier to work with and even do the bare wire with one crimp and then the insulation section as another, it can be done in one step and I believe it was meant to. The 2.54mm Dupoint is done in the smallest of the 3 sizes on the SN-28B marked on the one side as 0.25 and not the large one that is marked 1mm (I expect using too large a slot will overly flatten the connection or not end up with a tight enough crimp or both). It seemed best "not" push as hard as you can, just go until it barely releases the ratchet as to not smash the connector, even at that with the wire I used it was slightly wide from being crimped. I carefully used pliers to narrow it back. These are small and delicate connectors and a hefty tool with enough force to wreck them if you over do it. Also putting them in upside down or not aligning them properly would easily wreck them. The two crimps I did to test the process and tool both worked perfectly. See in the pictures as assembled and in the one with the Red one I did beside a factory done one on a white wire. I found a very good video over at youtube titled "Using IWISS SN-28B Crimper" which is virtually the same tool, but if you watch it note that the dies (crimp head) are installed in reverse on his tool compared to the Glarks model I received today. His process seemed to be a very good approach and likely more inline with the intended usage than "multi step" methods I saw being suggested, which on their own may work very well too. Also the ratchet can be released by that little lever on the short handle side that comes out when it engages as it is closed (incase it slips you Can back it off and maybe save the connector rather than hopelessly smash it)

I used to have a professional grade crimper with several dies for various wire crimping needs. I can't remember the brand name, but it cost a couple hundred dollars. Sadly it came up missing one day. So I needed a new crimper for the tiny 2.54mm (0.1") dupont connector pins (which is what is used when making connectors for the Raspberry Pi GPIO pins). When you're dealing with such tiny pins, you need a well machined die in your crimper, or you're just going to mangle a bunch of pins and get real frustrated. Heck, even with a good crimper like this one it can be frustrating working with such small pins (especially with these old eyes!) This crimper is surprisingly high quality for its price. It is easily as good if not better than a lot of others at two or three times the price. Unfortunately, it does not take the same size dies as many other crimpers (what seems like a standard size). These dies are smaller. But so is the crimper.Be wary of the other reviews that say this crimper is bad. I'd bet money that those folks don't have any experience using a crimper on these tiny pins. If you don't know just how to do it, it will be very frustrating. I suggest watching a video on it. There are several on YouTube specifically about this crimper model. Once you know how to use it, you'll be making dupont connectors lickety split.

I gave it four stars because of the lack of instructions on how to properly use the device. I had to use YouTube to get an idea on some of the techniques which by the way are needed to properly complete a terminal crimp. Otherwise this tools design and function are as advertised. I used it to replace my electrical connector on my vehicles cooling fan.

So glad I bought this tool, although I have no need for it. Looked for some crimpers and for some reason that one was purchased. It is not even close to what I was looking for, and I started out not even looking for anything, well maybe something, but nothing like that, believe me. Now that I have the tool, it feels good in the hand, like solid yet easy to use. Got some end to end connectors for low voltage electronics, so now I can use the tool too. So many things in that kit with the connectors, could make all sorts of fun stuff. Going to watch tv, this concludes ...something, no sure, but have fun, thanks.-P

I purchased 2 other crimping tools, and both of them failed on the first or second crimp. The jaws on those tools are onmade of some king of sintered material, and is very brittle. I searched for an alternative, and came across this crimping tool, and took a chance because it say the jaws are "made of carbon steel". Whether this is true or not I cannot say, but the tool is working great for me. My use so far has been Dupont connectors, and the tool produces nice tight crimps on the metal connectors and have no problem being inserted into the black plastic housings. I will add that I'm using a 2 stage crimp. A rough crimp in the center slot, and then a finish crimp in the first slot. This works well for me, and I'm very pleased with this tool. Definitely recommended.

male pins are bent in such a way that they do not engage the detent, do not stay in

Not real impressed with these. They work alright, but definitely won't get you a perfect crimp every time. I usually have to finish them off with the pliers. One of retaining rings broke off on literally the first pin I ever crimped with these. Do yourself a favor; spend a few extra bucks and get the IWISS brand ones.

This is listed as 0.1 to 1.0mm2,but actual die on the tool is for 0.25 to 1.0mm2.0.1mm2 < 0.25mm2 Otherwise seems like a good tool.