IWISS XH2.54/3.96,PH2.0,PX,JST,Molex,Dupont Terminal Crimping Tool SN-01BM Rachet Crimper AWG28-20 (0.08-0.5mm ²)

The sleeve is not properly fitting with metal handles

I use this tool for crimping JST XH pins. I gave it 5 stars for ease of use but crimping these small pins is not easy; at least not yet since I am a complete novice to crimping those pins. Positioning of the pins in the tool is the difficult part. Once that is accomplished the tool operation is easy. I also purchase a kit with pins and connector housings. Many of my first crimps were near failures in that the retaining tab was crushed back into the pin and I had to dig it out for the pin to function. I also purchased pins from a popular electronic components company that worked much better in that there was more clearance for the retaining tab to be clear of the tool for the crimp. There was also more spacing from pin to pin on a string of pins. Keeping the pin on a short string rather than breaking the pin off an then trying to insert it into the tool makes pin insertion more manageable. The slightly wider distance between pins helps.

This crimp tool is listed as suitable for the Molex KK254 terminals (Molex p/n 08-50-0114). But it's not really good for those. The die is not wide enough to encompass both the wire and insulation sections of the terminal at the same time. So either you get a good crimp on the insulation or on the wire, but not both. So then you have to shift the terminal and crimp again. This often results in the terminal being bent or otherwise deformed so it won't slide easily into the Molex housing. (Example: Molex housing p/n 22-01-3027) I gave it 4 stars because it's a really nice tool. It's slick. The ratchet and everything work really well. It's just not suitable for the KK 254 terminals. I returned it. I'm still in need of a crimper that works with those.

it does exactly what it is supposed to do

I use the Iwiss crimper tool with the SN-01BM die to crimp the pins for JST XH 2.54mm connectors, using 22 AWG stranded wire. It works extremely well. The fact that it crimps in both places (the wire insulation and the wire, which are different sizes) simultaneously, which means you don't have to crimp twice, is very convenient. The ratchet feature is also very convenient. The tool also releases automatically as soon as it's delivered the precise amount of crimping force so you don't have to think about that. Specialized crimping tools used by professionals cost hundreds of dollars (some even more!). This tool is under $25 and it works perfectly. There are so many types and sizes of connectors and tools that you have to select the right tool for your connector. Assuming you've done that, you need to learn the right way to use it, e.g. which way the pin goes in the crimper, where to place it, how much insulation to strip off, proper wire gauge, etc. For those folks who say they haven't had a good outcome with this tool I can only imagine that there is some detail like the above that they haven't attended to.