Are all "F" crimps the same?  Open barrel uninsulated type. - Page 1
Forum section: electronics / projects

author: r-mm
author_rank: Contributor
timestamp: December 30, 2020, 03:13:17 am
content: Hello allI was testing my new Pressmaster crimper with the 4300-3146 die used for uninsulated .250" terminals.https://www.waytekwire.com/item/567/Pressmaster-4300-3146-Die-Set-for-Non-Insulated/These come in many flavors and it crimping them was going along nicely until I tried it with some TE Fastin-Faston terminals - the ones with locking lances. The portion of these terminals looks longer than usual and the crimper mangled it. TE's spec calls simply for a "F" crimp which is what I thought this was.Am I missing something?https://www.mouser.com/datasheet/2/418/2/NG_CD_60249_G1-1254687.pdf

author: wraper
author_rank: Unknown
timestamp: December 30, 2020, 03:34:20 am
content: They are made for different wire cross sections. So you need die(s) for multiple sizes. As this connector (AWG 16-12) falls in between 2 jaw sizes on particular die, one jaw should fit better than other depending on wire size used. But I personally would not use it for AWG 16.

author: r-mm
author_rank: Contributor
timestamp: December 30, 2020, 03:36:05 am
content: Understood I should have said I used the appropriate jaw size in my die and since I was on the cusp (16ga) I tried both the 22-16 and 16-14 jaws with similar results.

author: Monkeh
author_rank: Super Contributor
timestamp: December 30, 2020, 03:40:27 am
content: They're really brave suggesting that's good for a 16AWG wire. As indicated, with an insulation support that huge it's intended to crimp two wires and would need a die to suit.

author: r-mm
author_rank: Contributor
timestamp: December 30, 2020, 03:41:40 am
content: I tried it with a 12ga wire and while the crimp looked better, it wasn't wonderful.

author: tooki
author_rank: Super Contributor
timestamp: January 01, 2021, 01:54:15 am
content: Quote from: r-mm on December 30, 2020, 03:13:17 amYes, you are missing something."F" just means the type (shape) of crimp — it saysnothingabout the size. That's what the crimp dimensions in the datasheet tell you.The key thing you overlooked was the specification in the top right corner of the datasheet:3. INSULATION RANGE TO BE 4.06–5.33 OR TWO 3.30.Typical insulation diameter for standard PVC-insulated 12AWG wire is 3.3–4mm, and for 16AWG it's around 2mm, so this terminal is designed for wires withverythick insulation. As such, it's going to need a normal size conductor crimp but a huge insulation crimp. (And offset a bit, so that the insulation is more or less centered in front of the conductor.) So no way it's going to work in a standard die.In other words, you inadvertently picked up a specialty terminal made for unusual wire.

author: coppercone2
author_rank: Super Contributor
timestamp: January 01, 2021, 04:14:49 am
content: thickness of crimp material original sheet

author: r-mm
author_rank: Contributor
timestamp: January 01, 2021, 05:21:27 pm
content: Thank you very much - greatly appreciate the help. I made the mistake of looking at the AWG range summery on the site where I purchased the terminals and not the TE data sheet.Quote from: tooki on January 01, 2021, 01:54:15 am

author: tooki
author_rank: Super Contributor
timestamp: January 03, 2021, 06:08:08 pm
content: Quote from: r-mm on January 01, 2021, 05:21:27 pmWell honestly, I think the electronics components industry could do a LOT better in its documentation. It drives me bananas that one is forced to pore over datasheets with a microscope and lice comb to figure out the differences between nearly-identical parts because they’re too lazy or incompetent to list the keydifferentiatingfeatures prominently. (I worked as a technical writer for years, and I so I KNOW it can be done better because I’ve written datasheets where I came up with a simple way to show the differences between product versions.)FWIW, on Digi-Key they do have the insulation diameter as a parameter on their terminals, albeit not as a search filter. But at least it’s easy to read on the product page.

author: exe
author_rank: Unknown
timestamp: January 03, 2021, 07:15:46 pm
content: I'm yet to learn how to use crimpers. Every time for me it's a nightmare. I really struggle to match jaws with connectors. So far pliers worked the best for me. Last time, after a lot of struggle, I got to know that for insulate lugs I need a different crimper :/. The only thing that never let me down is a universal ferrule crimper like this onehttps://cpc.farnell.com/wiha/41246/automatic-crimper-for-ferrules/dp/TL19993, it just works.Ideally, I'd just buy a kit with a crimper, assortment of lugs, jaws, all marked with matching color codes and a manual with pictures.

author: wraper
author_rank: Unknown
timestamp: January 03, 2021, 07:18:20 pm
content: Quote from: exe on January 03, 2021, 07:15:46 pmAre you serious? It's about as reliable as simply wrap the wires around with no crimping.

author: exe
author_rank: Unknown
timestamp: January 03, 2021, 07:23:12 pm
content: Quote from: wraper on January 03, 2021, 07:18:20 pmWell, it passed my "pull" test. On the other side, I've seen bad crimping in commercial devices where connectors fall off the wires.

author: tooki
author_rank: Super Contributor
timestamp: January 03, 2021, 07:33:15 pm
content: Quote from: exe on January 03, 2021, 07:15:46 pmCrimping is a precision process that requires a delicate ballet of precisely controlled brute force. It’s not difficult to learn, but demands that the tool and the terminal be carefully matched. Note that more expensive crimpers that are dedicated to a particular terminal will have locators (terminal holders) that make the process infinitely easier and more reliable.Quote from: exe on January 03, 2021, 07:15:46 pmSoooo... why don’t you do just that?https://www.knipex.com/index.php?id=1216&L=1&page=art_detail&isMobile=&parentID=1313&groupID=1314&artID=4013Quote from: exe on January 03, 2021, 07:23:12 pmWraper is right though: pliers simply do not apply the force needed to perform a proper crimp. The fact that shitty crimps exist doesn’t mean pliers are a good choice. They’re absolutely not.FYI, with many types of terminals, the pull test will appear to succeed (on what’s actually a bad crimp) thanks to the insulation crimp. That’s why for pull tests, you actually have to do test crimps without any insulation crimp (either by stripping the wire back extra far, or by amputating the insulation crimp wings before crimping).

author: exe
author_rank: Unknown
timestamp: January 03, 2021, 08:00:01 pm
content: Quote from: tooki on January 03, 2021, 07:33:15 pmBy no means I'm promoting pliers.PS I looked at knipex... Wow, the price is insane. I also don't see any fully insulated lugs (I'm looking here:https://www.knipex.com/index.php?id=1216&L=1&page=group_detail&isMobile=&parentID=2719&groupID=1314). For the price they ask, I guess I can hire a professional with his/her own tools and materials to crimp 10-20 connectors that I usually need to make on average per year.PS is solder connectors a thing? (I know that you guys love talking why soldering is not recommended, but may be for less demanding applications it's an option?)

author: wraper
author_rank: Unknown
timestamp: January 03, 2021, 08:08:24 pm
content: Quote from: tooki on January 03, 2021, 07:33:15 pmThe issue is that pliers can apply enough force but not in right directions. Instead of taking proper shape which tightly envelops the wire, terminal will be simply flattened. Even if you flatten the terminal with tons of force, wire will still stay loose after force is removed.

author: tooki
author_rank: Super Contributor
timestamp: January 04, 2021, 02:05:34 am
content: Quote from: exe on January 03, 2021, 08:00:01 pmActually Knipex is among the more cost-effective options, among top quality tools. Crimping is a deep, deep, DEEP rabbit hole, where one discovers that original manufacturer tooling is eye-wateringly expensive. Like $300-1500 expensive. For asingle tooldesigned to work with asingle terminal. (As in, sometimes you even need a different tool just to crimp a different gauge wire!)But oh, do they work nicely. I have a $350 AMP crimp tool I picked up NIB for $60, and for its terminals (and others with very, very similar crimp dimensions), it's so nice to use. Every crimp comes out perfect, and there's no fiddling around with how deep to insert the terminal or the wire.The trick, as a hobbyist, is to not pay retail price for such tools: buy used or surplus tools. They may be beat up and worn out, and may no longer meet the calibrations that defense/aerospace/production environments demand, but they'llstillperform better than a $10-40 junk crimper. You'll typically find e.g. a $500-1000 crimper selling for $50-150 on eBay if you get a halfway decent deal.If you do decide to buy new, $100-200 for a single crimper (or $200-400 for a set with different dies) is the sweet spot: it probably won't be original manufacturer, but in that price range you can find stuff like Knipex that does have precision-made, polished dies that actually work well.For what it's worth, insulated terminals are kinda the one exception to needing top-quality crimpers, IMHO: the plastic obviates the need for precision dies. (Of course, they're inherently not the best terminals, but work fine for many applications.)I bought a few $15-ish ebay/aliexpress crimpers for insulated terminals, and it was 2 out of 3: one, no matter what, does not apply enough pressure. The other two seem to be OK. This is where you might do well with, for example, Farnell (aka Newark aka Element 14)'shouse brand tools, where you might spend $30-50 on a crimper, but it'll be good enough, and if it doesn't work, you can actually get it replaced under warranty.

author: tooki
author_rank: Super Contributor
timestamp: January 04, 2021, 02:14:17 am
content: Quote from: exe on January 03, 2021, 08:00:01 pmAbsolutely. But not for that kind of terminal, as far as I know. (By "insulated lug", I assume you mean a fully-insulated spade-type connector.) But for example, if you have screw connectors that you can attach circular lugs to, you can get solder lugs.Soldered connectors work fine, but have to be kinda treated with kid gloves, in that they must be thoroughly relieved of stress and vibration if they're to be reliable in a dynamic environment.The kind of connectors typically seen with soldered connectors are things like military/aerospace circular connectors. Then the wires are carefully bundled and stress relieved within the connector shell.And let's be clear, too: a poorly crimped connector can be less reliable than a badly soldered connection. The comparative reliability people talk about is in reference to properly-assembled connections. I think it probably is fair to say that for a low-skill user with only basic tools, their soldered connections will be superior in quality to their crimped ones.