crimping faq

[Fred]

Hi,

I just wanted to thank whoever wrote the crimping faq:

bought a ratchet crimp and some crimps but neither came with instructions so I was not quite sure how to use them.

I didn't know whether you had to crimp each end of the butt crimp (which the wiki tells me I should do) or whether I needed just one crimp in the middle (wrong).

When I did some practice crimps, the plastic got "chewed up" and I wasn't sure whether that was supposed to happen, but I see from the photos on the wiki that that is right.

So thanks very much, that page has really helped a complete crimp beginner.

By the way, are all crimps equal or are some better than others? I bought a selection box from CPC but find the central metal insert can slide when positioning the cable. Do all of them do this or is it just that mine were cheap and nasty?

I have encountered non-insulated crimps in repairs in the past. Could the page be updated in the future to give an introduction to these?

TIA, Fred

[Dave Plowman (News)]

That's why the article is there. ;-)

Chewed up? It should just take on the profile of the crimp tool without perforating. It's insulated for a purpose.

Cheap and nasty. The central stop is pressed etc from the metal part of the crimp. Or should be. Many of these crimps are of as poor quality as the crimping pliers supplied with cheap sets, so I only now buy mine from a decent electrical wholesaler.

The principle is the same. Use good quality terminals and the correct good quality tool. The problems with crimps is there are so many - and each one

*must* have the correct, often expensive, tool.

[Dave Liquorice]

B-)

There is a bit of possible confusion in the section refering to puting heat shrink on. To me the word "wire" means a single core from a bundle all contained within a single "cable".

I'd edit the page but it's locked, no doubt due to spammers. I thought I had a login but the user list doesn't show me. Has the user list been purged?

[Tim Watts]

Hi Fred,

Very nicely done - I cannot see any ommisions or inaccuracies (caveat - I read it quickly). I think it covers all the basics, including NOT using crappy Halfords car grade crimp tools.

re uninsulated - I have used these in 10mm2 for earth bonding wires because regular plastic crimps do not go that big. But unless you need to join big wires, most DIY use would center around the plastic coated jobbies.

Is it worth mentioning ferrules (bootlace)? Different crimp tool, same principle - I prefer to crimp off find stranded wires encountered in lighting fittings if they need to go into screw terminal blocks. Also useful for shortening fly leads on RCBOs.

Cheers

Tim

[John Rumm]

The user list was purged of spammy users - but they were all in a particular form not like any of the real user names. So hopefully no real accounts were knobbled.

Drop me an email with your preferred user name and I will make a new account for you and send you the password.

[John Rumm]

Rough night Tim? ;-)

I think Fred was commenting on it, not writing it. That pages has been there since 2007 and has has over 25,000 page view since.

Yes, good point actually. Might be worth adding a section on those.

[John Rumm]

The plastic should get "formed" to the profile of the jaws, although not chewed as such...

They can vary. Some have internal serrations for a better grip. The central stop is not full radius, so if using a bigger crimp than required for the wire, then you can push it right through. However something like 2.5mm^2 T&E in a blue one will probably not push through. Experience also teach you how much insulation to trim, and that limits how far you can go.

They get a mention in the required tools and materials section. However I did not have an uninsulated crimp tool to hand to photograph and so did not cover those in detail. For most cable joining activities, using uninsulated terminals means more time spent heatshrinking.

[Fred]

Sorry, perhaps I used the wrong word. Perhaps I should have said "squashed". Mine look like those in the photos, so I am sure it is my language that is wrong, not my technique!

Regarding the uninsulated crimps, the ones I have seen are not like those linked from the wiki but like these:

"open ends" which the tool wraps around onto the wire.

Thanks, Fred

PS just to clarify: I was only commenting on what a useful resource the page was and I didn't contribute to it in any way.

[Dave Plowman (News)]

The photos are correct.

Generally forget Maplin for anything serious. For Lucar terminals and tools I use these people:-

do crimp tools too.

one I have - it is excellent - is also the most expensive one, at the top of the page. It produces crimps to factory standard.

FWIW, I'd not use any pre-insulated Lucar terminal on flex - as you'd get in a car. They quite simply don't crimp as well as the correct thing. Cut off the insulation and examine the crimp if you don't believe me - it will be found to be just squashed and untidy. The correct tool on an uninsulated terminal has heart shaped jaws which cause the terminal to wrap round the flex and grip it perfectly.

[Tim Watts]

Yes - I realised that after hitting send. Bed at 3am - painting the kitchen...

[Fred]

Thanks. I haven't bought crimps from Maplin (my cheap ones were the duratool brand from cpc), it was just that Maplin was the first link I could find showing that type of crimp with the ends that fold heart-shaped onto the wire. Is that what "Lucar" is?

I was looking to link to this web site, which I had seen before but I just could not remember its name. I think you are right: I had seen these types of crimp in automotive applications rather than domestic mains use before.

So you have their PR3 model. It doesn't look like it is a ratchet type, is it?

TIA Fred

[Dave Plowman (News)]

Lucar is (or was) the name for the spade connectors found on older cars. And some electrical stuff. Think it may have something to do with Lucas.

They do use a heart shaped crimp - but so do most other terminals for flex. Insulated connectors are quite rare in just sort of squashing them up.

I have seen them used for mains - but obviously inside a box so they can't be touched when the device is in use.

It's a cantilever design. That produces enough force easily to crimp the connector fully without the pain of a ratchet. I suppose it isn't quite so foolproof, though. I do quite a bit of car wiring and find it as near perfect as any tool I have. But expensive if you won't use it much. Some of their cheaper ones may be OK - I've never had a problem with anything from them.

[Fred]

Thanks for the clarification. It was just those on the TLC site, as linked from the wiki, appeared to be the squash them up type rather than the fold a heart type, so I wasn't sure whether there were two different types with different names.

I would not use them enough to justify the cost of a PR3. I was thinking of their PR4 model. It is a ratchet, which I understand provides the right amount of force and is best for beginners. I was surprised they sell the pliers that were explicitly criticised in the faq. The faq says only to use them to shear bolts but I've always used a hacksaw for that purpose.

Do you crimp coax connectors too? At the moment, I use the screw on F connectors. Is there any advantage using the crimp type?

TIA, Fred