How To Use A Cheap Air Impact Wrench

I picked up a cheap air impact wrench from a certain retailer of cheap tools (rhymes with beers).  It is rated for up to 400 ft-lbs of torque, supposedly.

When I connected it to my 6 gallon "pancake" air compressor, and tried to use it to loosen my car's lug nuts, it was unable to budge them.  In fact, I could hold the socket with my hand, and feel that it was really feeble.

Then I read the instructions.  The recommended air hose is 3/8"ID, while my hose is a 1/4" ID, and I also have 1/4" fittings all around.  No wonder, the small hose and fittings are so restrictive, the impact wrench probably doesn't get enough air flow to do its thing.

So I went to Home Depot (which is like a pilgrimage site for me, I circle it's aisles many times...) and picked up a modestly priced 3/8" ID hose, as well as some 3/8" "automotive" fittings.  By the way, the 3/8" fitting kits were more expensive than the hose itself!

At home, I removed one of the quick connects from my pancake compressor and using some nylon plumbers tape to make a good seal, screwed on the huge 3/8" automotive connector.  Then I put the matching bits on my hose, and on my air wrench.

Now, the air impact wrench whacks off the lug nuts like a champ.  The air flow is obviously much improved--running the air gun continuously will drain my 6 gallon air tank in about 30s.  Which is why the instructions recommend a 20gal tank.

But don't let that dissuade you.  If you only need to use your air impact once in a while (like me, to rotate my tires), it will work.  You may have to give your compressor a little bit time in between pairs of nuts to rebuild its pressure.