Instructables
Picture of Properly crimping a copper welding lug.
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When you're installing welding leads, a copper lug is very important for attaching the leads to the welder and the ground clamp. Proper attachement of lugs is a must, as they must take a lot of power, and be well connected to the wire to conduct it well, and because they at the ends of the leads, they also take strain from all the movement they will see during their life time. 

Considering this, it's surprising how often I see welders that have lug improperly installed on the leads, most often resulting in the leads pulling partially or fully out of the lugs.
 
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Step 3: Insulator beveling.

Picture of Insulator beveling.
I like to slightly bevel the end of the insulator, letting me push it in slightly for a nicer look and a tighter fit. Just tkae your knife and slightly bevel the end.

Step 4: Fitting.

Picture of Fitting.
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If you eyeballed it right, then when you push the wire into the lug it will fit nice and snug, and you'll have to really push it. If it's too long, it won't fit all the way in, to short and it will fit in too easily.  In the first photo i stripped it a little too long, so I trimmed the copper a little until it fit in nicely (second photo).
Bi111 year ago
For what it's worth, I do battery cables more often than welding cables, and have the correct toggle type crimper available. After crimping, I still use this method as an added clamp. I have more faith in this than a (proper) crimp. Experience in hostile envoronments has taught me to do so.
mineinc1 year ago
I thank you for the post but I have seen the wire move over time with this method and pull out.
If you wish to know for sure that your lug will be held forever you can take your cable and lug to most electrical wear house supply's or your local power company and they will have the proper crimper and die that will make a perfect hex crimp that will hold the wire from all sides of the lug. And if you only need a couple done they will do it for free.

Good Luck!
bstarling1 year ago
This works just fine. I have done the exact same thing, only with a chisel many times. No problem, this is not rocket science and frankly I don't give a flip what an inspector has to say about it. Also have wicked in solder on certain high vibration applications on marine and other equipment. Do this along with the fine crimp you made with the screwdriver or chisel.
bstarling1 year ago
This works just fine. I have done the exact same thing, only with a chisel many times. No problem, this is not rocket science and frankly I don't give a flip what an inspector has to say about it. Also have wicked in solder on certain high vibration applications on marine and other equipment. Do this along with the fine crimp you made with the screwdriver or chisel.
Bill WW1 year ago
Good Instructable, should work fine.

This site is about how to fix/make/design on our own. We could all hire to get the work done, or buy expensive tools.

The method Steven explained could come in useful in emergency situations. If you are a boater like me, you realize that do-it-yourself ability can be a life saver. In an emergency, you never have the perfect tool available.

As a positive suggestion, I keep a old pair of garden pruners, ("anvil" type, not "shear"type) in my workshop for cutting heavy cable. They will cut 000 gauge (10 mm) copper cable smoothly

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whait861 year ago
dont listen to these nay sayers, good instructable.

@shteef and superpants, when has anything on this website been done in a professional manner (aside from critisism) this site is about the backyard builder. doing things a diffrent way to avoid paying lots o money is what its all about. if we all took our stuff to be handled and built and fixed or whatever this site would be called wheretogetthingsdonable.com
shteef1 year ago
If you go to a decent welding supplier or quality auto-electrical distributor, they can sell you a proper lug crimping tool. That way you won't have to do a nasty bodge-job with a hammer. You should also use proper cable shears, not a knife when working with wire/cable. I'm sure your a fantastic welder, but you shouldn't really be giving advice to do a job like this mate.
oldanvilyoungsmith (author)  shteef1 year ago
First off, I'm a professional welder, halfway through my machining degree, and a knifemaker/blacksmith.
I'm not an idiot who's going to try and cut copper cable thicker than 1/2" with a knife. I was stripping the cable with it, if you read it, you would have seen that. Ask any electrician, using a knife for stripping cable is both a good way to do it, and very commonly done.




And secondly, I was taught this method by a professional welder who has been welding for many more years than I've been alive, and he has had great success with this method when done right, as have I. I'm sorry if it isn't the "Shteef approved method".
You do it how you like mate, that's your call. But as someone who trains both domestic and automotive electricians, I think it's wrong of you to imply that yours is the 'correct' method. Here in Australia and also in the UK, if a work place health and safety inspector caught you crimping with a screw driver and hammer or de-sleeving wire with a pocket knife you would be ejected from the work site.
oldanvilyoungsmith (author)  shteef1 year ago
Your still not understanding.
This isn't for the professional electrician working in an industrial plant or something. A place like that would have the money to buy the high end quickconnect ends for welding leads anyway, and those attach differently.

This is for the guy at home who just got the stuff for his new welder and isn't sure of a good way to attach the wire to the copper lug. Most time I see someone who did that, they stick the wire in the lug and hammer it flat. Resulting in it squishing partially out and not being a good connection, as well as failing prematurely.

As for stripping the wire with a knife, sorry, but my strippers don't fit the large welding leads, and none of the shops around me are about to have strippers that large, and I'm not about to spend $50 or so to get them to order me set, just so I can strip 3 cable ends for my welder. And yes, a knife works fine, and I know plenty of electricians who use a knife for stripping large wire like this.
A crimping tool for the welding lugs you show in your instructable is available for about $100, cable cutters (which you would use to safely remove the insulation on the cable will cost about $50). If you are having to replace the lug regularly you would have to be doing a lot of welding. Welders, like all tradesman earn pretty good money and can and should buy proper tools for the job(they can claim for the tools when they do their tax return). Therefore a professional welder should use the right kit properly and safely. If an amateur welder is doing this then a safer way of fitting the lug would be to use a lug with a small hole at the other end to the cable entry and holding the cable with a vice, heat the lug with a blow lamp and flow solder into the hole.

Advising anyone to crimp a terminal with a screw driver and hammer or de-sleeve wire with a pocket knife is just plain dangerous and wrong. As has been previously been stated it may be fine as a one off when your out in the sticks but it is NEVER the correct way to do it. You could probably peel a banana with a chainsaw, but that doesn't make it correct!
superpants1 year ago
Using a screwdriver in the method shown may sometimes give a good crimp and is a reasonable ‘field repair’ technique, It isn’t a reliable or repeatable method. Wherever possible you should try and use the correct tool for the size of the cable and the crimp lug. As Shteef points out, professional electrical suppliers or welding suppliers may well have the tool available for loan, or you local auto electrical store can help you if you don’t want to purchase the tool.

Getting the technique wrong can result in either premature failure of the cable (as the copper is overstressed or sheared by the crimping action, a high resistance joint- resulting in overheating of the joint, poor mechanical strength, where the cable can pull out, or access for moisture for corrosion to form.

There is quite a bit of science and technology behind forming a correct crimp, that is reliable and lasts. I have an Instructable that goes into much more detail if you want to have a look.
rimar20001 year ago
Useful info, thanks for sharing.
Awesome. I just started to do some metal fabrication, I'll look at the the lugs on the ground leads on our shop welder sometime... Thanks for the excellent post.