How does crimping work?

It's the case too with a properly made crimp. Which very few are outside of the factory. There's no such thing as a universal crimp tool - each connector and cable requires a special for the very best results.

There may be some expansion on release of the crimping pressure but the interior of the crimp junction is still under pressure.

Regards ........ Rheilly P

Friction, then chemical, and maybe a bit of adhesion.

Could well be - I've not had it analyzed. But it certainly doesn't look like copper. ;-) Of course it could be all these sort of things are copper in the US. I can only speak for the ones I'm familiar with in the UK.

Spade connectors have to have different properties to lugs because they rely on spring tension for electrical continuity but proper bolt on lugs are usually copper for copper cables, aluminium for aluminium cables.

Yes - I did ask if 'lug' had a special meaning in this context.

I just sort of assumed the discussion was more about electronic terminals than heavy duty power distribution. Hence my reference to computers, etc.

Good grief... Cite a reference.. How is a reference better than actually having the item in hand. I say the reference is any piece of equipment that has crimps in it. Anyhow.. Someone happened to cite the needed info..

BTW, I'm seeing huge variation between lug types (same colour - different brand). I bought some fully insulated ones - and could pull them all off with no difficulty. The ones I had in my stock from way back either failed by tearing the conductor - or had a strength exceeding mine, and didn't fail.

At least there was some consistency - lugs out of the same box performed the same as each other.

The crimping tool has a 'pressure' setting, but comes with no guidance on how to decide which pressure to use.

Sylvia.

The ratchet tool provides substantial mechanical advantage compared to many of the cheap tools, and therefore enormous pressure on the joint. With the right tool, the joint is squashed down by the exact amount, whereas cheap hand tools are more "hit and miss" as to whether you have applied the right pressure to them. the "die" is also a lot better on ones that I have seen, and probably designed to put the pressure in the exact right places at the right time during the crimp. (ie, more efficient use of the energy you apply with your hands)

As the metal parts of the surface being crimped are squashed really hard by the tool, they probably heat up (compression causes heat, and metals expand with heat,), and then shrink as they cool, tightening on the wire ?.

OK, so clearly you don't have a clue, no evidence or facts to base your lame assertion on, so...

I've asked several times, and he's avoided doing so. Mainly because he's off on cloud nine, with no idea what he's talking about.

I suspect everyone else knows that bronze is much too brittle to use as a crimp on connector, but Dave hasn't gotten that far yet.

It is possible that some spade connectors are made out of phosphor bronze (especially the ones used in heating devices like stove elements) but the discussion was about crimp lugs

If by fully insulated you mean the red blue and yellow types available in a variety of configurations - the colour determining the cable sizes catered for - they vary wildly in quality by maker, as do the crimp tools. Some seem to be made out of 'silver' foil. But even with the best, it's interesting to cut off the insulation after crimping and examine the quality of the crimp, especially at the bottom end of the range catered for. To me, the only really satisfactory crimp is the type that forms a heart shaped cross section after crimping - and those don't.

I know what copper looks like. Clearly, you don't.

Somebody probably ought to let the manufacturers know about that!

... and lots of others, of course.

So we can add bronze to brass as metals you can't tell the difference from copper?

The particular application is connecting to the terminals of an SLA, so these connectors have the advantage of minimising the scope for extraneous contact when they're in place.

Shame they perform so badly on the pull test.

Sylvia.

I too have seen these red terminals pull off a cable within their stated range.

I prefer non insulated 1/4 in spade connectors that have a separate insulating cover. They have a better cable clamp too. This sort:-

Made of brass, strangely. ;-)