Question: what is the difference between a 1/4 and 1/2 impact driver?
Answer: Impact drivers will make short work of lag bolts or lag screws, up to an extent. A driver with a 1/4 inch or 3/8 inch bit can be the better choice for smaller screws. A 1/2 inch impact driver or an impact wrench may actually deliver too much torque that the screws or bolts are quickly stripped, or worse, snapped.