crimping spade connectors -- fail!

[coppercone2]

that bit about the wire in the crimper being so compacted is a bit of a sales pitch

cut one apart with a hack saw and take a pick to it. Crimps are good but the claims are getting a bit ridiculous IMO.

this is what you need for a cold weld of a single strand

[pdenisowski]

Except a real engineer wouldn't ever do that, because it's a waste of time when the simple crimp suffices.

Speaking as a real engineer:  I value efficiency when I'm at work, but I sometimes grossly overengineer things when I'm wearing my hobbyist hat

If I were attaching 100 spade connectors a day at work, I would almost certainly just crimp them.  But if it were just a few for some project at home, it would be hard to resist the temptation to solder them too ... just because ....

[Psi]

This thread ran well until reply #18, mainly talking about what the right tools for crimping are and generally giving tips on suppliers of tools and terminals etc.
Helpful to the OP, I think.

Then it went astray... something to think about.

Fair call, I shouldn't have put more light on the crimp vs solder argument and risked restarting the argument.
And for that I apologie.


But equality this statement of yours is pretty bad.

Soldering is the worst option ever, not just for spade terminals, but for all stranded wire connections.

Stranded wire connections are soldered probably 10000's of times every day, all according to manufacturer recommendations.

[tooki]

I'm with you on this though, soldering a crimp terminal is fine if done by someone who knows what they are doing. You only get problems when idiots do it and allows the solder to wick down into the strain relief area. Which is easy to avoid if you know what you're doing. And most engineers do.

I think that's a wildly optimistic statement. Technicians know what they're doing with regards to assembly methods. Engineers very frequently do not.

Crimping is not as electrically robust as a solder joint. There's a risk the wire may pull out even if crimped following the right procedure and with the right tool.

A bad crimp is not electrically robust, and may risk wire pull-out.
A good crimp exceeds the robustness of a soldered joint, and the wire will break before it pulls out. A good crimp is a cold weld, with the strands and connector fusing to a solid piece of metal.

The correct tools will produce a good crimp every time. But that does require that the tool, contact, and wire are all perfectly matched to each other. That's why crimping is not always sensible for hobby use or other low-volume applications.

You have to 'trust' that a crimp is good because you used the correct tool to do the crimp and you followed the correct procedure. It's kinda like using a BGA in that regard.

There are test procedures. In proper crimping, periodic test crimps are made to verify crimp dimensions and pull strength. Some (but not all) crimp types allow each individual production crimp to be tested. But with a well-controlled process, it's not necessary.

The bare minimum is a ratcheting tool, since the ratchet ensures a particular amount of force has been applied before it releases. This introduces reproducibility into the process, so that a test crimp (which can be tested destructively) is representative of production crimps.

Nothing wrong with crimping and in many applications it's good and it's the best option.

Above, you make it sound like a terrible thing. But you're comparing poorly-executed crimps to expertly-executed solder joints.

But choosing to solder a crimp terminal is a valid thing to do, there's just risks involved that you have to be aware of.

Just because something is intended to be used one way does not automatically make it wrong to use it in a different way.

Some crimp terminals can, others categorically must never be soldered. (I have seen some that expressly warn against it because of how reheating can affect the heat treatment of the contact spring itself.)

The issue, however, wasn't the question of whether to solder a crimp terminal instead of crimping it, but whether to crimp it and then apply solder. If the crimp was done anything close to properly, adding solder to it will only make it worse.

The only thing worse than that is to apply solder (e.g. tinning the wire) and then crimp it, since solder cold-flows under pressure, and will eventually loosen. (Solder-crimp-solder is basically just soldered, and you may as well skip the crimp.)

[tooki]

For the none insulated terminals, I use the KNIPEX 9121215B
It is a well made tool.

Though Knipex is a good brand, I do not recommend non-ratcheting crimp tools, since you can’t be sure enough force has been applied.

For simple terminals, this Knipex tool is perfectly alright and works very well.
Ratcheting crimp tools of course is the professional way to go and they are offered by a subsidiary of Knipex, called RENNSTEIG
https://www.rennsteig.com/produkte/kategorie/Crimp-System-L%C3%B6sungen/25134.html

Of course Knipex/Rennsteig offers proper crimp tools, too.

I stand by my statement that I do not recommend non-ratcheting crimp tools, since the crimp force is unknown (some people have enormous hand strength, others are very weak) and thus it's a totally uncontrolled process.

[coppercone2]

Can someone show me a disassembled standard crimp that is fused into a cold weld in the middle?

[tooki]

Can someone show me a disassembled standard crimp that is fused into a cold weld in the middle?

See https://www.eevblog.com/forum/reviews/what-crimping-tool-do-you-use-for-quick-connect-terminals/msg1003774/#msg1003774

[mikerj]

I stand by my statement that I do not recommend non-ratcheting crimp tools, since the crimp force is unknown (some people have enormous hand strength, others are very weak) and thus it's a totally uncontrolled process.

You simply squeeze the tool until the metal parts just up from the grips meet, it has sufficient leverage that this is very easy for even the weak of hand.  I'd be the first to agree that those Knipex crimps are not a professional grade tool, and you wouldn't find them being used on e.g. an aerospace project but they do form perfectly good crimps (on the correct types of terminal) and are easier to use than ratchet crimps IMO.

[coppercone2]

I wanna put a pick in that crimp to see how well it holds up to some prying

I have seen things that look incredibly uniform but when you apply a bit of sharp pressure it turns out to be bogus

[coppice]

I stand by my statement that I do not recommend non-ratcheting crimp tools, since the crimp force is unknown (some people have enormous hand strength, others are very weak) and thus it's a totally uncontrolled process.

The ratchet is a nice convenience, and its a good way for production people to roll a set procedure all day. However, the ratchet just detects if the crimp tool has fully closed. I've never seen a crimp tool without a ratchet where you can't clearly see from metal touching metal that the thing has fully closed. It just takes a little more care and effort.

[coppercone2]

it also clicks so no one can argue that it did not close if you heard it click. Infact it would still be jammed shut if this failure was my fault. Can't put it in the chassis if the crimp tool is stuck on.

I am waiting for the day where someone finds a crimp tool jammed into the chassis so something can be put together for final test on a friday. Like a ratcheting 0 gauge crimp tool inside of some industrial machine. Because it was the last tech guy there and the tools needed to unlock the jammed crimp tool were locked up. Just zip tie the tool, screw the cover on, drop off at test and go home. easy.

Actually its more likely then you think if its the last crimp and the lead time for more is 10 weeks and the wire is already stretched to almost yield point because someone optimized it to the nearest nanometer.

and the best part is if they find it at some mine or whatever, and the production schedule is so tight that they put it into service after consulting engineering for some extra duct tape, who says changing tension is just too risky.

[thm_w]

I stand by my statement that I do not recommend non-ratcheting crimp tools, since the crimp force is unknown (some people have enormous hand strength, others are very weak) and thus it's a totally uncontrolled process.

The ratchet is a nice convenience, and its a good way for production people to roll a set procedure all day. However, the ratchet just detects if the crimp tool has fully closed. I've never seen a crimp tool without a ratchet where you can't clearly see from metal touching metal that the thing has fully closed. It just takes a little more care and effort.

Here you go, knipex 97 21 215



If the tool costs the same, but takes more care and effort, I don't know why I'd use it.

[Benta]

However, the ratchet just detects if the crimp tool has fully closed. I've never seen a crimp tool without a ratchet where you can't clearly see from metal touching metal that the thing has fully closed.

Wrong. Apparently you've never possessed a crimp tool with ratchet.
It ensures correct pressure, yes. Not very important.

But it's essential for easy operation, unless you are born with three hands.
Operation is as follows:
1: place the termination in the crimp tool correctly (meaning up/down and small/large side) and close the tool until the first ratchet "click". This fixes the termination in the tool without closing it.
2: insert the wire and crimp.
Without the ratchet, you're juggling with termination, wire and tool in free space all at once.

[Benta]

Here you go, knipex 97 21 215

Why do you bring in the same POS that the OP had problems with?

[coppice]

However, the ratchet just detects if the crimp tool has fully closed. I've never seen a crimp tool without a ratchet where you can't clearly see from metal touching metal that the thing has fully closed.

Wrong. Apparently you've never possessed a crimp tool with ratchet.
It ensures correct pressure, yes. Not very important.

The main problem with crimping comes from not using appropriately sized parts and tools. If you do match them the non-ratchet tools work OK. If you don't the ratchet ones close and release and give you just as useless a result as the non-ratchet ones.

[Monkeh]

Here you go, knipex 97 21 215

Why do you bring in the same POS that the OP had problems with?

Because he's not on an irrational crusade to prevent people using things which work.

[vk6zgo]

And most engineers do.

Except a real engineer wouldn't ever do that, because it's a waste of time when the simple crimp suffices.
Totally pointless.

Down the track, a Real Technician will probably be stuck with soldering because the EE didn't crimp the connection properly, & didn't allow enough extra length to easily redo the crimp connection with a new lug after it failed.
A Real Production Dept person is meanwhile screaming to get the thing back.

[Benta]

The main problem with crimping comes from not using appropriately sized parts and tools. If you do match them the non-ratchet tools work OK. If you don't the ratchet ones close and release and give you just as useless a result as the non-ratchet ones.

Yes. Don't use the wrong tool. Why didn't I think of that?

[coppercone2]

and the customer will be waiting 4 weeks for it to be released after special inspection

[coppice]

I stand by my statement that I do not recommend non-ratcheting crimp tools, since the crimp force is unknown (some people have enormous hand strength, others are very weak) and thus it's a totally uncontrolled process.

The ratchet is a nice convenience, and its a good way for production people to roll a set procedure all day. However, the ratchet just detects if the crimp tool has fully closed. I've never seen a crimp tool without a ratchet where you can't clearly see from metal touching metal that the thing has fully closed. It just takes a little more care and effort.

Here you go, knipex 97 21 215



If the tool costs the same, but takes more care and effort, I don't know why I'd use it.

That tool is a piece of garbage. The lack of a ratchet is not the problem. It doesn't have properly formed jaws. Its just a connector squasher.

[Benta]

Because he's not on an irrational crusade to prevent people using things which work.

Why do you think I'm "he"?

[Monkeh]

That tool is a piece of garbage. The lack of a ratchet is not the problem. It doesn't have properly formed jaws. Its just a connector squasher.

I wonder what the genuine tooling for these types of connectors looks like?




Yes, they're somewhat better supported, but it's just going to be plastic extruding in different directions. It is, however, a lot harder to reliably exert sufficient force on the 'squasher'. Not a tool I'd recommend either, but I have made perfectly functional crimps with that type - and they're less sensitive to the various different forms of insulated crimp than the usual jaws on ratchet crimpers.

Because he's not on an irrational crusade to prevent people using things which work.

Why do you think I'm "he"?

I never said you were. If your best response here is to try and shame me for using a pronoun in a gender-neutral manner towards another person, you may want to find something better to do with your time. Perhaps take up that crusade - somewhere else.

[xavier60]

Some examples of crimping fails. Take a close look at the photos in this listing.
https://www.ebay.com.au/itm/125932616918?hash=item1d522b3cd6:g:xnQAAOSwtP5iYpKM&amdata=enc%3AAQAIAAAA0FV%2BPQTz43UNlFpHkFc4Cr6RhJX0LmTfPono1Ux5sKhLQuOrcJxVqkrgiBVQQl2R648KWy9vB%2Fdy%2F815kQ5haFGIsH93QKeQpfidNCQ6rwdO8gL%2BJRSFEfD3MyjOcS%2BAGUYNaM6%2FOqrOPzVX%2FQSJF7WXh2XZZe442Oiym%2BEBI%2Bn8X8beZpXk7c0JbU7Krz6E5UG%2Feb3Uf8CrN694Ud6GOkGq2N78TeTraU0sweWFWBItLn8JmO%2BJjyT6D2BoVclbFGqjl%2Fc19MvTRRFjKllACIk%3D%7Ctkp%3ABk9SR7rFhuy8Yg

[Psi]

The correct tools will produce a good crimp every time.

This is where I disagree.
Maybe the correct tool that is also in perfect condition. Sure, I can accept that.
But you can never be sure to the same level that you can when soldering.
There's always a risk the previous user of the tool damaged it in some way that's non-obvious. Or that it's just worn out. Or any number of factors that may cause the crimp to be sub-standard even though the correct tool and technique was used.

[coppercone2]

no way, that means you would have to buy like a crimp height micrometer or even a pull tester. I don't think that is a real possibility. I assure you those tools are just for decoration !11