Introduction: Properly Crimping a Copper Welding Lug.

By eagle eye forge
About: Hi, I'm stephen, I'm a certified welder, working on my machinists cert, and working part time at a hardware store. Mixing in all of that with my hobbies of blacksmithing and knifemaking, only makes for more f…

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.

Step 1: Tools

It's rather simple and easy, all you need in the way of tools is -

Hammer
large flat head screwdriver
knife
and sometimes you might need some cutters for trimming the wire.


Supplies, all you need is the wire you want to make leads from, and a copper lug for your size wire.

Step 2: Stripping

You want to trim the wire to the full length of the lug, remember, you want all the connectivity you can get.

Step 3: 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.

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).

Step 5: Crimping

Set the lug on a hard surface (concrete floor works), and lightly tap the end with hammer to snug the wire. Don't hit it hard, if you flatten it too much it will just push it out instead of holding it. If you do it right, it should hold it nice and snug.

Now, take the screwdriver and put the blade lengthwise on the collar, and drive it in, creasing the copper collar. Do this along the whole collar. I like to also turn it over and slightly crease the backside. When done right, it'll hold forever.