What is the difference between a quick release drill head and an SDS?
What drill head does your drill use?
Although some drills can be used with either drill head, we can generally distinguish which type of drill is equipped with which drill head. This is shown clearly in the table below.
What's the difference?
The most important difference between a quick release drill head and an SDS drill head is the way the drill bit is attached. On a quick release drill head, you spin the drill bit into place with 1 hand motion. This is enough to keep a simple wood or metal drill bit from slipping. An SDS drill head has a click system, where you click the drill bit into a shaft. This makes slipping impossible, but it does allow the drill bit to move back and forth. This is necessary to be able to drill holes into rock hard materials like concrete.
Any other differences?
You might've thought that was it, but SDS drill heads in turn can be divided into 2 types: SDS-plus and SDS-max. They look very similar, but an SDS-max drill has an extra slot and a wider shaft. This means you can use it for the heaviest duty, such as demolition jobs or drilling large holes into concrete. SDS-max drill heads are seen mainly on demolition hammers and hammer drills. Chisels, for this reason, often have an SDS-max shank. Note, though, that SDS-plus drill bits don't fit SDS-max drill heads and vice versa.
When should you use which drill head?
Battery drills and impact drills, in most cases, have a quick release drill head. This, then, automatically means that wood, metal, and stone drill bits generally have quick release shanks too. In order to drill holes into concrete, natural stone, or other hard materials, you'll often use an SDS drill head. If you're tearing down a wall or chiseling away joints between tiles, you'll do that with an SDS drill head, too, since the chisel needs to be able to make a chopping motion here.
What about the accessories?
A wood drill bit with a quick release shank won't fit on a Combi hammer with an SDS drill head. A concrete drill bit that has an SDS-max shank won't fit on a quick release drill head either, no matter what. Nor would you want to. Remember the kind of drill head that's on your drill when buying drill bits and chisels. Extra drill heads or adapters are included with some drills. This allows you to use both quick release drill heads and SDS drill heads.