Question about using a torque wrench on aluminum lugs

I was helping a friend rewire his garage in Phoenix and saw him just crank down on the aluminum lugs with a regular wrench. I told him the spec sheet for the panel said 35 inch-pounds, but he said it didn't matter. How do you guys make sure you're hitting the right torque without slowing down too much?

4 comments

4 Comments

the_jana3mo ago

That spec sheet is right, aluminum lugs are easy to strip. I just keep a cheap inch-pound torque wrench in my bag for exactly that.

paigep853mo agoMost Upvoted

Just crank them down tight.

the_claire3mo ago

Ever just go by feel? I used to do that all the time until I rounded off a lug. Now I'm with Jana, a cheap torque wrench is the way to go.

hugoj121mo ago

Wait, he said it DOESN'T MATTER? That's WILD to me. Aluminum lugs are SO soft compared to copper, you can strip them out in half a second if you're not careful. I watched a buddy ruin a whole subpanel once because he just "torqued it to spec" with his arm on a 12-inch wrench. That was a 500 dollar mistake. You absolutely HAVE to use a torque wrench on aluminum, no question about it. That Phoenix heat alone probably makes the metal softer too.