Car Questions

Clear all

Choosing an impact wrench


Topic starter

looking to take my DIY skills up a notch and change my daughter’s wheel bearings.  Thinking it might be time to get my first impact wrench to speed the project.  

I don’t have an air compressor.  Of the electric ones, it seems to be that the battery-powered ones are handy but don’t give you as much bang for the buck as corded ones and quickly lose power as the battery runs down.  It that correct?

And excuse me posting multiple questions in one thread, but what torque rating should I look for to get an axle nut off?

4 Answers

small passenger car axle nuts will be in the neighbourhood of 110 N·m (81 lb ft).

There's nothing wrong with good quality battery tools. Unless you're running a busy shop, you shouldn't have any battery issues. But they're pretty expensive. No cords is really convenient and nice.


Air tools are the gold standard, oodles of power, but require compressors and air lines, so will also require significant capital investment. But compressed air sure is handy for many tasks. Refinish your kitchen while you're at it LoL  


I don't have experience with corded tools because it's not an attractive option. Heavy expensive tools, and dragging extension cords around.


Honestly, Bob home owner doesn't need to bother with impact wrenches for routine maintenance tasks. It's overkill when a decent breaker bar is all you need. I just get socket adapters for my impact driver and I used it to spin off and on nuts&bolts after I've cracked them, to save a bit of time. I already have the driver and the adapters are a couple bucks a piece.



You might want to consider an air compressor if you have a place to put it. For occasional home use a 120-volt direct-drive air compressor can work OK to run air tools, though you'd want one that can deliver the volume of air required by the tools you intend to use (most mid-range 1/2" impact guns would need 4 to 5 CFM at 90 PSI) and has a big enough air tank like 20 gallons or more.

I've had a compressor like that for over 20 years, a portable unit on wheels in back of the garage, and it still works fine since it only sees limited use. (I'm certain it would burn out quickly running constantly in a real shop environment.) It's great to have shop air available for a multitude of purposes.


I am not a mechanic, but a fellow DIYer. I have had corded and cordless impact wrenches. I had to return them both, because I couldn’t fit those things in the spaces I needed to work. Both were too big and super heavy to maneuver. They worked great for areas with ample room. But not for those nooks and crannies.

I ended up just using a breaker bar and extensions. An extension to access the bolt, and a pipe to lengthen the breaker bar. 

When I am in the market for another impact wrench, I plan on getting the smallest for factor, as light as feasible, yet most powerful, brushless, and cordless. It’s more of a long term wish list. 

(FWIW, the corded one I tried was a Harbor Freight house brand. And the cordless was the bigger heavier but cheaper DEWALT.)

The cordless dewalt was cheaper than the harbor freight House brand corded?

Oh sorry I mis-wrote.

I meant to say I just got the cheapest cordless DEWALT. Which was still more expensive than the corded Harbor Freight.


I would definitely recommend getting a half inch impact depending on how much you want to spend 

The cheapest is going to be the harbor freight tools  I don't have any experience with it so I don't know how good it is but you can look up online and see what people are saying. I personally have a Ryobi and it is pretty good I've never had any problems with it. I also have a rigid which is a bit more powerful but it actually would randomly not work on me . if you want to be really fancy you can get Milwaukee or DeWalt