I have the Dewalt screw gun / impact wrench. From experience it can and will snap 1/4 bolts. I suppose if you are very light on the trigger it may work but have found throttling back a pneumatic impact works much better. Throttle to the point you get a "whack" about every half second or slower if you can get there. Kroil seems to work best as penetrating oil.
Dan Bentler
