There are times when a conventional drill won’t get the work done. For example, when you’re installing a deck ledger against a concrete foundation and need to drill a lot of holes, you would like a more specialized tool. That’s when you might obtain a hammer drill or a rotary hammer. While the names are usually used interchangeably, they are not similar tools.
Hammer drills and rotary hammers:
Hammer drills and rotary hammers are both excellent for drilling masonry. Rotary hammers are more powerful, though, and have a “hammer-only” mode with no rotation. They usually have Associate in Nursing SDS chuck, that is better for blow.
Hammer drills are excellent for lightweight masonry:
A hammer drill works best at drilling holes in bricks, mortar and concrete blocks. But it may handle the occasional hole in poured concrete. You don’t get to pay loads of money on hammer drill bits, but more expensive bits are usually equipped with excellent inorganic compound tips, and also the tips are a lot of securely connected to the shank of the bits, that reduces breakage in heavy use. As the name implies, this tool delivers a hammering action as it drills. This action is formed by two internal metal disks with ridges. As the disks spin against each other, the seams ride up and down and cause the chuck to move in and out.
Hammer drills can have the pound action turned off; with the flip of a switch and also the swap of a small amount, you can go from drilling in the concrete block to boring into wood framing. Typically, these tools will use up to a 1/4-in.-dia. The bit when acting on poured concrete. A 3/8-in.-dia. Or smaller bit can be used in block and masonry.
Rotary hammers are for larger jobs:
Rotary hammers excel drilling holes in hardened concrete. A rotary hammer may be fitted with all kinds of different attachments. The most fashionable style of the chuck on the shelves at home centers these days is the SDS-Plus. SDS-Plus bits have grooves on the shanks that lock firmly into the chuck but allow the bit to move back and forth independently of the chuck. They’re super easy to insert and remove—no tools needed. Some of the incredibly massive rotary hammers have a similar system, but larger called the SDS-Max. And there are a few brands that have proprietary systems, so make sure the bit you purchase matches the tool you’re using.
For more massive holes, a rotary hammer is a go-to tool. A rotary hammer uses a piston to compress air that moves a striker to make the pound action. The rate of the blows is slower than with a hammer drill, but those impacts are much more powerful. Consider the hammer drill as delivering various jabs and the rotary hammer as transport off with haymakers. The facility of the rotary hammer suggests that less work for the user, but it also means the rotary hammer is not suitable for use on wood or metal.
Since the pound-force isn’t created by a spinning mechanism, as it is with hammer drills, rotary hammers are often switched to hammer-only mode. This is useful for lightweight demolition work like tile removal. Rotary hammers are generally bigger, weigh more, fight larger tasks, and needless work from the user. They do, however, cost more, so if the job doesn’t imply it, getting a rotary hammer might be overkill and wasted dollars.