Home renovation and decorating tasks are easier and better when you use the right tools. However, there are so many types and styles of drills on the market that choosing the best tool for your particular job can be confusing. When deciding whether to purchase or use a hammer drill or an impact driver, understanding the basic differences between these drills and the purpose of each can help you make the best choice for your particular needs.
The hammer drill looks like a conventional drill. It is pistol-shaped with a long nose. It has an adjustable chuck that holds the drill bit in place. Many have an adjustable clutch at the front end near the chuck. The clutch allows you to set the point of tightness in which the drill will stop tightening a screw, thus not inadvertently driving a screw deeper than you want it to go. Hammer drills produce a hammering action directly downward onto the drill bit and thus the surface you are drilling through. Imagine someone tapping a hammer against the back of the drill while you drill a hole. This tapping action of the drill provides an additional chipping motion to the drill bit when you drill through hard surfaces such as concrete and ceramic tile.
The impact drill looks a little different than a hammer drill; the impact drill’s nose or barrel is much shorter. Instead of an adjustable chuck, this type has a quick lock connection that accepts specific types of drivers. This drill will not accept a drill bit without an adapter and is not primarily made for drilling holes. Best cordless Impact drivers produce a sideways or rotating tapping action. In the interior of an impact drill is an anvil mechanism that activates when the twisting action becomes difficult. This anvil begins to tap and assists the rotating action of the drill, making the tightening motion much easier for you and making it less likely to strip out the screw head. Sum up: a hammer drill taps in a forward motion; an impact driver taps in a rotating motion.
When to Use a Hammer Drill or an Impact Drill
Hammer drills are designed to drill holes in hard, porous surfaces such as concrete. Use a hammer drill when mounting things on a concrete wall or drilling a hole in a concrete patio or ceramic tile. Impact drivers are meant to add twisting force when tightening or loosening screws, nuts or bolts. Use an impact driver when hanging cabinets or tightening or removing difficult-to-turn screws or bolts.
Usually, the best buy is purchasing a combo pack that comes with both a hammer drill and an impact driver. You can purchase a set of cordless tools designed for use around the house for around $150 as of January 2014. A contractor quality set designed for everyday usage will start at about $250.
Source Credits: http://homeguides.sfgate.com/difference-between-hammer-drill-impact-driver-95417.html