SDS Drills have the advantage of a simple spring-loaded chuck, so that bits can be chucked with a simple and quick hand action. The Special Direct System shank and chuck are uniquely suited to hammer drilling in stone masonry and concrete. The drill bit is not held solidly in the chuck, but can slide back and forth like a piston. The hammer of the SDS Rotary Hammer Drill acts to accelerate only the drill bit itself, and not the large mass of the chuck, which makes hammer drilling with an SDS shank drill bit much more productive than with other types of shank.
