TIL the hard way about using a 3/8-inch drive on a big 1-1/4 inch bolt

I was putting together a big header for a boiler in a plant near Tacoma and had to choose between my regular 3/8-inch impact and the heavy 1/2-inch one. I went with the smaller one to save time, but it just couldn't break the bolt loose and I ended up rounding the head a little. Had to go get the bigger gun anyway and it zipped right off. Anyone else have a rule of thumb for when to just grab the bigger tool first?

3 comments

3 Comments

derek_schmidt61mo ago

That's a classic case of the tool working harder than you. A 3/8 drive impact is really meant for fastener removal, not breaking big stuff loose. The rule I heard is if the bolt head is bigger than a 19mm, just skip right to the half inch gun. Saves the headache and the bolt head.

alice_palmer201mo ago

Ever try to use a 3/8 on a crank bolt? Learned that lesson the hard way, and @derek_schmidt6 is right about skipping to the half inch. My old gun just made angry noises until I gave up. Sometimes you just need the bigger tool for the job.

stella_murray1mo ago

Bet a 3/8 could do it with a cheater bar.