Hi, my name is Dan and I’m a crimpoholic.
Honestly, I didn’t know I was a serial abuser of crimping tools until this weekend. I’ve been working on a small solar power system, and on Saturday I found myself struggling to get the BMS installed on the battery. I bought a Bluetooth dongle to connect the BMS to a smartphone app for checking the individual cells of the battery. I assumed it would just plug right into the UART port on the BMS, but alas — different connectors. So off I went to my bench, looking for a sensible way to make the connection.
My first thought was to simply log the connector off the dongle and solder the leads to the traces on the PCB right below the UART port. But then I saw that the pins in the port looked like 0.1″ pitch, so I rummaged through my stash to see what I could find. To my surprise, I had not only a kit of 0.1″ female crimps and housings, but I also had the crimping tool for them! I had no memory of making the purchase, but I thanked my lucky stars that I did, and got on with the job.
I Think I Have a Problem
The story would end right there, if it weren’t for the nagging feeling that my good fortune meant something more. As I worked on my project, I made a mental catalog of the specialty crimp tools I have. Then I wandered around my shop and my garage, collecting every crimping tool I could find. Rounding them all up and laying them out, I had the unavoidable thought: Man, you have a problem!
The full collection is shown here — I think; something tells me there are more tools lying around that I’ve forgotten about. But even still, what I managed to find is a pretty impressive collection. I even threw in some “crimp-adjacent” tools, like the red-handled trio in the lower left, which includes the OG crimper-stripper-cutter-bolt cutter, a jack-of-all-trades tool that is equally bad at every one of those jobs. But it’s where I started, and the tool had been with me for decades, so it’s earned a place of honor.
![](https://hackaday.com/wp-content/uploads/2022/03/PXL_20220327_195220794-e1648501476294.jpg)
For the most part, though, I’ve moved on to ratchet-action crimp tools. I find these superior in every way to simple crimp tools, especially since they can’t easily over-crimp a connector. The blue-handled tools in the black case are my go-to crimper these days, even if the crimp connectors included in the kit are a little on the crappy side. Right below them is a ferrule crimping set, which I purchased immediately after writing an article extolling the virtues of ferrules.
The yellow case is interesting. When I got started in ham radio, I figured I’d invest in the tooling needed for Anderson PowerPole connectors, the de-facto DC connector in the amateur radio world. The tool standing up vertically takes care of those crimps, but the other tool is — a good question. Like most ratcheting crimp tools, it has interchangeable dies, and there are spare sets in the kit that are for PL259 connectors — also handy for amateur radio — but I don’t think the die set in it is what it came with. I think it might be for crimping the really big Anderson connectors, which I needed when I wired an inverter into my car. But that’s just a guess, so if you recognize the die, sound off in the comments below.
If the Tool Isn’t Right…
My most recent purchases are the two kits are the far left, both of which are specific to my solar power endeavors. The lower one is for crimping lugs onto battery cables from 8AWG to 2AWG, which is hard to do with anything other than a specialized tool. Just above that is a nice kit for making solar cables with MC4 connectors. I actually haven’t even had a chance to use that one yet — but it’s nice to know I have it, in case I ever need it.
And I think that’s the main lesson behind this somewhat extravagant collection of specialized tools. I really hate trying to make do, especially when it comes to critical connections. And when you’re talking about connections that might carry upwards of 100 amps, you really shouldn’t be fooling around. I can’t count the number of “how-to” videos I’ve seen on YouTube that try to convince you not to waste money on specialized crimp tools — just smack it with a hammer, squeeze it in a vise, or even just slobber it full of solder.
None of these seem like great ideas to me, especially after reading Maya’s recent article on the dangers of substandard crimps. And so when it comes time to incorporate another type of connector into my projects, chances are I’m going to buy the right tooling to go along with it. After all, while most of these tools aren’t exactly cheap, they aren’t going to break the bank, especially when you consider the price of failure.
So maybe in the end, being a crimpoholic is more feature than bug.
Great! an excellent opportunity to ask if anybody knows of a good crimping tool for the 2mm Hirose connectors that we all use once in a while
I use them occasionally enough to want a real crimper (rather than sort through one of my “other connector but close enough” options) but not often enough to spring for the official $500 tool
Maybe the Iwis IWS-3220M
I’ll have to get myself one of those.
I looked, and I have an Iwiss 01BM in the drawer. It’s a good tool, with nice, cleanly formed, crimp dies, but it doesn’t *quite* work on some of the connectors of that size (not that you can actually buy any of those parts in 2022, but that’s another story)
the 01BM goes down to 26WG, the 3220M has jaws for 32AWG. (and is a parallel action tool too)
Hey… I didn’t see one of these: https://www.harborfreight.com/hydraulic-wire-crimping-tool-66150.html
Worked a treat for crimping 2/0 lugs… and aircraft cable.
Those make a good actuator for all sorts of things. Here is a rivet-squeezer that I made for cold-setting 3/16″ steel rivets.
http://bodgesoc.blogspot.com/2014/04/hydraulicrivetsqueezer.html
Wouldn’t use it on aircraft. I like my cables to fail above the rated cable spec, not under.
I had a good experience using this for 2awg on a mobile solar battery compartment.
These are all over eBay for much cheaper – the dies can be badly sized but stepping down a size usually works perfectly, you can operate them one-handed whilst holding the cable. Very handy pieces of kit.
obligatory, “I feel attacked.” :D
the only dangerous number of crimping tools is less than all of them.
Just last night I was soldering on some PowerPole end caps then trying my best to crimp them with pliers and a vise. I was successful after longer than it should’ve taken. Everytime I do it without the tool I think “I should spend the $40-50 they want for the PowerPole crimp tool”, then when I sit down to order I think “$40-50 for as infrequently as I crimp PowerPoles?!”
Well, thanks to the People’s Republic of China, I’ve come across some “power connector crimper tool” items that work with PowerPoles but they’re careful to not invoke Anderson’s name on the major retailer websites.
The best connection is always a mechanical one, not a soldered one. Especially in high current situations, solder only adds resistance, and ends up causing strain relief issues, as the solder ends up creeping up the wire into the insulated part. This makes the wire near the connector more brittle due to the inability for the strands near the connector to individually move, and allow for flex of the wire at the connector (personal experience). Then, there is the heat generated in the solder, which can even melt the solder, and break down the connection alltogether. The crimp alone makes the best low resistance connection (connector directly to wire),
I don’t crimp all that many Power Pole connectors either, but spent the $$ to buy the Anderson crimper, and am glad I did, every time I use it. I also am glad I purchased all the other specialized crimp tools I have for the many other crimp connectors I use. The only crimper/crimp insert that currently alludes me is one for JST-XHP connectors. All that I find miss the measurements I have taken of the actual connectors I have from different manufacturers.
Hilarious!
Check further down the comments regarding NASA procedures. The resistance in solder is correct, but NASA gives other good reasons.
If you MUST solder, do it after you crimp.. the solder could melt/soften in a high/over current situation… If you are crimped to a soldered wire things will get loose, and fail over time.
There are problems involved with soldering after crimping. One, once crimped, the wires in the crimp area are deformed to make the wires contact even more surface, and solder won’t really flow. Another issue is the insulation, just crimped for strain relief, will melt, eliminating some of that strain relief. Last but not least is the solder that will wick up into the wire, beyond the strain relief, rendering the strain relief useless.
I worked for a US company that made MIL-STD products and we found that crimping alone or soldering alone wasn’t a reliable enough connection for the abuse received out on the field. The assemblies were also typically potted in SYLGARD silicone based potting compound to reduce shock and vibration. The enclosures were some kind of carc painted steel. I’m forgetting the type of wire insulation now, but it was comparable to silicone grade, but not silicone. It was crimped, pull tested, soldered, and pull tested again. MIL-STD approved as well.
Arguably not all products need this, but to this day I still take the time to do it because crimp terminals can loosen over time and temperature, and I’m not a cable assembly contractor with $$$$ tools :D
Be nice if rental places carries tools like that.
The “I have no clue what this crimping tool is for” is something I have stumbled over a couple of times.
And in my experience, the text written on the tool is rarely of help when one finds one of these odd ones as well, and sometimes the handle has gotten a new die so the text isn’t even applicable…
To be fair, one should document what tools one has and don’t have. Similarly to documenting what components one has at hand, else one ends up buying yet another set of something one already had…
While I agree, that does generally require the luxury of space and time in sufficient abundance to pack up carefully and create proper homes for all new tools and components every time or you still end up buying duplicates because you can’t find the tool/part you know you have somewhere…
In my case stuff has to get stuffed away anywhere it will fit with 5 mins of warning far to often to keep a proper inventory or even manage to keep every projects assemblies and parts properly stored together, so every now and then when time and space is available I pull my hair out trying to rectify the mess and finish some of the hurriedly shoved away project.
Yes, giving everything a home is really hard.
I have for some time kept things organized on a spreadsheet, keeping rough estimates of what I do have at hand. So that I don’t even up buying another 100+ 7400 series chips that I do already have on a shelf….
Though, where exactly a given component is, that is another question. I have though organized things a bit based on if it is an active component, or a passive one, if it is connectors or cables, etc. Few things have a specific home, more a general area where they should be somewhere within. And still some stuff grows legs and disappears…
I am still poking about trying to find the 50 stepper motors I know I have somewhere. (Though, loosing them were easy, since they are only 5 mm in dia and at most 8 mm long, they are tiny…)
I just bought my first crimper, after realising I wanted to wire up 44 dupont connectors on a ribbon cable and realising that with my old technique of poorly arsing around with needle-nosed pliers it would take all day to do and also not work.
And you know what? Crimping is _hard_. Positioning the metal thingy in the crimper properly, inserting the wire the right distance, knowing what setting the crimper needs, even knowing which crimper slot to use because apparently dupont connectors are amazingly poorly documented. But even with my poor crimping technique, it’s still faster and better than with pliers. Not going back.
This is one of the benefits of the really high end crimping tools: they have little plastic adjustable gadgets that hold the pin in exactly the right alignment and depth so you don’t have to position them or worry about them rolling as the crimp starts.
Yeah. There are at least two official variations of TE’s Mate-N-Lok crimper: One is of the “dinosaur jaw” style, one is designed such that the die always travels straight.
The one where the die always travels straight is SO easy once you learn how a contact is supposed to be inserted. It has end-stops so that your contact is inserted at exactly the correct position in the crimper, and has guides to keep the wires centered relative to insulation.
In my experience those gadgets aren’t plastic – they’re metal on every crimper I’ve used.
Crimping is _hard_ when you first get started. When you get used to using crimpers, it becomes habit.
This is why I’ve moved to only using pre-termed cables or soldering all my connections. For the next project where I would like to have a tidy custom cable, I’m going to get a flex-cable instead and have an FPC connector. A little expensive, but looking on PCBway if you’re making a product, a 50x100mm 2-layer flex will run you $1.60per at qty100, and you get better return paths than anything but well-terminated twisted pairs.
I recently bought this tool to crimp large eye terminals for a 2001 F-150 (not mine) to solve phantom draws. You just can not do a proper job in the vehicle under the hood unless your crimper has 4 foot long handles for the amount of pressure needed to compress the wires and connector. Even removing the cables, I knew my ferrule swagger for wire rope (winch cable) would not make the proper connection.
Klutch 10-Ton Hydraulic Cable Crimper
https://www.northerntool.com/shop/tools/product_200773734_200773734
Basically no one star reviews about it breaking after the 3rd use. The benefit, imho, about this design is that not only are compatible dies available for smaller sizes on Amazon and such, the way the dies are held and compressed, you can make your own out of mild or spring steel using just a band saw and drill press. A very handy mobile tool.
No ethernet and other RJ-type connectors crimping tool?
Surely that can’t be correct, I’d think we all have one of those, and probably a punch down tool for ethernet/phone patch panels and sockets! But it seems to be true I can’t see one in that pile…
Exactly what I thought – no ethernet crimp … nor a punchdown tool (almost a crimp tool, no?)
I’m not sure that there is anything there for Molex crimps, either.
You are not a true crimpoholic until you can recognise a crimp terminal and select the exact tool for it without thinking about it.
Also, no crimp tool for the compression-style Quad-clad RG6 connectors, or hex BNC crimps (RG 6, 58, and 59, with the pins for the latter two)
I have an Ideal Crimpmaster frame that takes a multitude of dies (including a bunch from the clones pictured) and it’s been a workhorse for me with it’s RJ45 and RJ11/12 dies. I recently got a hydraulic crimper for putting lugs on #6 stranded copper- I could have bought a ratchet style one or a leverage style one, but my hand strength ain’t what it used to me. :)
I’d argue the real problem here is too many competing standards in the world of connections that require their own crimp tool – far too often there isn’t an actual physical/mechanical or electrical need for them to be different from other crimp connectors but that they are that way, because they have always been that way for x, or the cheap Chinese (etc) factory the part you are using came from uses y for everything but others use z – So you get stuck needing the new tool to crimp this or that end because its not compatible with your other crimp tools or breaking out the soldering iron to splice precrimped cables together as needed.
This is true. Pretty much every design is to either avoid a patent claim or to solve some problem with existing solutions that creates some other problem that causes someone to design a solution to solve that.
Something like a *cough* standards body with yearly dues for access to the closed plans?
free to use and truely open standards do exist, why use the nasty licensing methods…
https://xkcd.com/927/
I counted. I have at least 15 crimping tools (I say “at least” because I know that some are not on their tray under my bench)
Inexpensive ones that I like:
For Dupont and JST: IWS-3220M
For M23 and Lemo: Search Amazon for “Deutsch Indent”. There are two sizes available. They are acually more adaptable than the real tool, as the crimp position is adjustable.
For bootlace ferrules I like things like Amazon B09724DCJH which make a square crimp using a mechanism that looks like magic :-)
And then, something that took me years to find, a tool for insulated crimps that handles the 0.25mm2 size crimps (sometimes green, sometimes the _other_ yellow. ie, it has four receptacles rather than the usual three. HS-40J.
Where on Earth did you find the tool for the Other Yellow crimps?
I had to modify a dosgy AMP crimp tool to handle them (badly).
Come to think of it …. where did you find your supply of 0.25mm^2 crimps?
(Mine are just a bag of old stock I picked up at a workshop clearance sale).
RS: https://uk.rs-online.com/web/c/connectors/wire-terminals-splices/fork-terminals/?applied-dimensions=4292033263,4292033571,4294885989
And now I know what the smaller than red, yellow, section is on my die-exchangeable chinese crimper. I always just thought that the colours had got mixed up in the factory!
Andy,
Thank you very much for pointing out the IWS-3220M Dupont/JST crimper! I have been searching for something with correct dimensions for quit a long time.
As mentioned in another Hackaday post, IWISS SN-025 is better suited for Dupont.
Yes, I found that when searching my email archive for the various tool orders.
The difference is round rather than W -crimp, IIRC.
So, yes, one needs one of those too.
One of those arrived recently, and I found that they must be running their EDM process so fast / stack so many blanks in one pass that the shapes get distorted.
When asked, IWiSS replied that distortions would be nominal. For wire EDM….
Anyway, I had to file the inner and outer depth stops smooth, loosen the screws and re-tighten with dies pressed together as well as dial up the crimper force to end up with acceptable results.
In conclusion, quality control is meh and you need to know what a proper crimp needs to look like to fix the unfinished tooling accordingly.
I also have multiple SN-01 crimp tools from another brand because it’s not guaranteed that you receive one that is close enough to be usable, and the smaller the contacts, the worse it gets.
And when you think the crimps come out right, it’s time for pull tests.
Where there are multiple suppliers for a type of crimp connector – like those common insulated lugs and splices used on boats – it’s best to standardize on a brand and get their tool. But it’s also possible to adjust most tools to work with a given lug brand.
For ferrule crimping, I prefer the hex crimps like B01JRE8AWO over B09724DCJH
Why do you prefer the hexagonal? I chose the square version only because all of the OEM equipment I work on use those. That version (same brand I believe) works very well. I would change in an instant if there was an advantage. BTW, Googled ferrule crimpers and those ones appeared next to a $450 Greenlee set 😬.
I feel that square-crimped ferrules fit in to cage-clamps more readily.
Especially when the cables are really a bit too big for the clamps, for example when running a bus from block to block to block with two strands rather than one in there.
Dan, got a link to that MC4 kit? Uhh, asking for a friend…
For some reason, NASA favors crimped cables saying soldering is unsafe. ROSCOSMOS likes to solder everything, saying crimping is not safe. Plays havoc when they need to connect two cables and the specialty connectors are either crimped or soldered.
I worked a bit in Russian aviation industry (civil). The problem with crimped vs soldered was mostly due to special tooling. For crimp, you need correct tool with correct positioner head. Russians has crimped connectors, but guys, who was doing the wiring jobs hated them mostly because they was rarely issued proper tooling (or spare pins). For soldered connector, they just need soldering iron and skill. Soldering irons was mostly 30 and more years old relics either straight for 27V or through small box with switch and couple of resistors as temperature regulation – wooden handle with heated metallic rod sticking out with 90 degrees bend at the end.
We was doing installations of US made equipment on Russian civil aircrafts and i personally witnessed situation (after we supplied all the tooling needed for the work to the factory), that the guy was issued crimping tool and single positioner head (you need specific positioner for each type of pin, sometimes there are multiple pin types in single connector) with the note from the warehouse “you will get another one after this one breaks”.
Second reason why russians liked soldered connectors was that is is easy to correct mistakes. You don’t need special extraction tool to get the pin out of the connector and if you find out, that you put the pin on wrong wire, you don’t need spare pin (with crimped you need to cut the pin a get new one, there is no “uncrimp”) – this was particularly important as spare anything was a problem.
While I personally hate dealing with high contact count soldered connectors because simultaneously holding a wire, solder, and an iron while also trying to manage to not burn all the other wires in the way is a huge pain, I can see the appeal of needing minimal tools, especially given the cost of many of the crimpers and the training they may require. I do see benefits and drawbacks to each type of connector, however.
The example you gave where modifications were performed to install new equipment without the correct tools is a failure on part of management. Sadly, I see those scenarios all over the place. That said, for crimped pins/sockets that get installed in “cannon plugs”, though the common crimp tool that gets used accommodates different “positioners” that holds the pins/sockets in the correct position during the crimping process and also has a small table that lists the crimp setting depending on the wire gauge used, you can, with a little care, manually hold the pin while crimping (though this would be tedious if you had to crimp a lot of wires). The only other thing you would need is a table written on a piece of paper that tells you what crimp setting to used based on the pin/socket and wire gauge. I’ve had to do that numerous times, but it’s a bit more convenient now a days because you can fairly quickly get the information you need by performing a web search. A few decades back it probably wouldn’t have been unless management/engineering support was willing to be helpful.
Having read the NASA study that Al is referring to and having built a few cable and wire harnesses for a high vibration environment (race cars) I gotta say, I agree with NASA. Crimp _and_ strain relief are mandatory. But I’m sure soldered and strain relief are just as good. The key is to keep the wire from moving relative to the connector. And don’t do it with zip ties. Use cable clamps!
But without the right crimp tool, it’s pointless. Saw a video of someone re-assembling an aircraft wiring harness with the ‘cheap first crimp tool’ and the red/blue connectors that pull off as soon as you look at them, I resolved never to fly in any of his aircraft!!
Just had a count. 5 crimp tools at my bench and a box full of the specialty ones below the bench. And a box of heat shrink.
Rumor has it that NASA prefers wax cord lacing to zip ties as well. (Myself, If I know I’ll be getting into the harness again? velcro wraps. If it’s going to be there for the life of the building/equipment? _properly done_ zip ties or wax cording, depending on just where it’s going and the likelihood of someone having to go in after me.)
That having been said, wax cord does have one major fault and that is that it’s messy as all get out- the wax gets _everywhere_, and it does not like high temperatures all that much either.
Not sure if the “rumor has it” is facetious or not, but you can actually download the NASA standards procedures for wiring online. Last looked at it within the past two months personally, don’t remember why.
My Grandfather worked at Sikorsky and thanks to this comment I just learned what the roll of waxy flat twine with his tools was.
NASA uses non waxed thread because waxed thread out gasses in a vacuum.
The rule in race car buying is remove $100 from the price for each zip tie you see. :)
NASA and the military always spec out crimps. No soldering because of solder whiskers. Microscopic bits of solder that will over time protrude off the joint and eventually with vibration break off and float in zero gravity.
Those solder whiskers are more correctly called tin whiskers. And they caused a couple of deadly Toyota crashes when solder joint solder whiskers in their drive by wire system shorted out the ‘pedal’, acting like the driver went full throttle.
[citation needed] :-)
https://en.wikipedia.org/wiki/Whisker_(metallurgy)#Toyota_accelerator_position_sensors_false_positive
(The page in general is interesting, on this subject)
Just ask anyone – the way the other guy does it is always unsafe if it’s not the way you do it.
I don’t mind paying for good tools normally, but a recent project where the debug cable used a hirose connector which needed a tool that cost nearly £800 does make me wonder if the manufacturer is having a laugh. In the end we bought some ready made cables for a few £ and chopped and soldered the bits we needed.
“For the most part, though, I’ve moved on to ratchet-action crimp tools. ”
We do a lot of wire crimping at http:\\brew-control.com. Just one of out controllers could easily have 16 or more crimped on terminals, and none of them can fail. I’ve bounced between ratcheting and non-ratcheting crimpers and I have given up on ratcheting crimpers.
And the reason is simple. A ratcheting crimper used for production will wear out and fail within a year and they don’t just suddenly fail to crimp. When they wear the crimps get loose and then those loose crimps fail later in test, or even worse they fail at a customer’s location. So now we use the heavy duty non ratcheting plier style crimpers, the ones that look like huge wire cutters.
I don’t even see one in your picture so here’s a link to one pair.
https://www.amazon.com/Insulated-Non-Insulated-Klein-Tools-1005/dp/B0006M6Y5M
And here’s another crimper that works well.
https://www.amazon.com/dp/B07PYGLJZC
This style of crimper has served us for years and once you get the feel of a good crimp it works every time.
If you look between the handle and crimp jaws, you will see a star shaped washer. This is used to adjust the crimp tightness over time. I have used ratchet crimpers in a production like situation assembling thousands of 75 Ohm HDSDI digital video BNC’s, interconnecting HD television broadcast equipment, crimping both the center conductor, and shield with the same tool, for several years with no issues. I just adjusted the star shaped washer as needed.
Agreed. In a production setting, from my point of view, the ratcheting crimper is a must. It forces the user to correctly complete the crimp. Periodic testing of crimps and adjustment of crimp displacement is good practice. The crimpers I had used had instructions from the manufacturer on dialing them in (and acceptable values for the pull-test). Non ratcheting is fine for hobbyists, or professionals, but not so great in a production setting where the person doing the crimping was pulled off the street and their only qualification is a heartbeat. (in my case it was pins for amphenol MS series connectors, probably a little more forgiving than coaxial stuff, but still not something you’d want a warm body trying to get right by how it ‘feels’)
The only solution for volume production is automated machinery. And hand crimpers would not even be allowed on a modern high volume production floor.
And BTW, in volume production pull testing is a destructive test. Even crimps that pass a pull test are discarded because they have been strained.
We also adjusted our ratcheting crimpers but even with that adjustment we wore them out in less than a year.
When I did cellular tower work I became acquainted with 2AWG crimping as everything had to be grounded to the tower. My hands were beat up for a long time 😅
Kind of surprised to not see this tool mentioned.
Pretty much everyone I know who does motorsport wiring has a pair of Hozan P-707. It’s a very flexible tool because it crimps the conductor and insulator separately, and also has dies to do round crimps required by some insulation. It’s the only crimp tool I’ve needed wiring automotive ECUs and sensors using dozens of different plugs.
https://www.hozan.co.jp/E/catalog/Crimpers/P-707.html
Insulation Displacement Connectors (IDC) FTW. You don’t have to strip and crimp individual pins with special tool.
Telecom was built on IDC type connections, and very few are crimp connectors.
Yes, amen! I use MTA-100 whenever I can and have the proper tool.
As for the crimp then solder concept: NEVER, PERIOD, END OF DEBATE
I have records of hundreds of pull test records to prove how much stronger a proper crimp is to a soldered crimp connection. If it is stronger after you solder then your crimp is incorrect and out of spec.
I love IDC – both mass termination using an IDC press tool, and punch-down are a joy …
… provided that your tools and terminations match.
What about the ratchet crimpers with the exchangeable dies?
One thing I didn’t see discussed it ‘where does one store all of these incredibly bulky and awkward tools?’ I keep the 4 or 5 most used next to the bench and the remaining collection in a 6 quart bin, but it’s sub optimal.
Mine are just in a toolbox dedicated to crimp tools. The crimps are stored separately (which needs to change)
For that assortment of ginormous and rarely used tools, I have seen a wooden box with dividers and polyethylene foam inserts (the hard stuff) that keep the tools upright and level with the top of the box.
Of course, there’s always the swing-out shadow-boards for the mass of tools.
If you’re into space optimization and don’t use crimping frequently: ~10mm SN style crimpers are popular, as are the ~13mm width ones. You’ll end up populating sorting boxes for m/f contacts, connector housings and THT/SMT headers anyway, so the die(s) can be kept with the contacts. Some sorting boxes also allow you to fit the entire crimper in the same box.
But then again, I’ve dedicated half a drawer to crimping tools now – stacked in an upright orientation – and my only regret is that it doesn’t say for which contacts each is on the handle.
An inexpensive thermal letterpress or lettering grinder may help.
On the other hand, a fine permanent marker may be all you need.
For my part, I tend to label the slots rather than the tools which works particularly well for things like drill and tap sets (old stiff neoprene foam mouse mats provide the structure for my organiser).