Tek Tip 2sD #3 - Impact Wrenches

Here are some 1/4" bits.

   

And here is a driver.

I like tools and these are like jools.  It's another 1/4" driver and uses the same bits but it's really well done and I take it out sometimes just to look at it.  I've got two.

Question - Which one can apply more torque?

Answer - The teeny shiny metal one can since the lever arm is much longer.

If you're looking for max torque, you could use a drill but an impact driver is better.  I bought this one a few years ago and it runs really well for little stuff.

That impact driver runs like a normal screwdriver until it encounters a threshold resistance.  Then it applies what I call an "impact torque" again and again and again.  This repetitive short duration  impact torque depends on the large inertia of you and the driver and the object along with the small inertia of the screw or bolt.

Your local auto repair shop uses a hydraulic powered impact wrench.

I recently bought an electric version to remove the  bolt on the front sprocket when I replaced my moto chain.  The nut I couldn't remove with a two foot long breaker bar was quickly removed with the Harbor Freight Impact Wrench.

Here is a cutaway of the operation of an electric impact wrench like the one above.

Last time at the tire store I couldn't see the shop.  They had it behind two doors with no glass.  They say I can't go in there for safety.  I'm pretty sure something else is going on.

Hold on tight  and use a vise because those impact drivers depend on inertia to resist the twist.  Newton's Third Law - Helicopter Version.