SDS Drill Settings Explained

Almost every SDS drill has a mode dial with two or three symbols on it, and using the right one makes the difference between a clean, fast job and a wrecked drill bit. Here is what each setting does and when to use it.

Rotary only (drill bit symbol)

The bit spins with no hammer action, exactly like an ordinary drill. Use this for wood, steel, plastics and tiles, normally with a chuck adaptor and standard straight-shank bits rather than SDS bits. It is also the right setting for glazed ceramic tiles even over masonry: start the hole with no hammer so the glaze does not shatter. Never run hammer action on materials that flex, such as timber, or on anything you care about cracking.

Hammer drilling (hammer plus drill bit symbol)

Rotation and hammer action together: the main event. Use this with SDS bits in brick, block, stone, mortar and concrete. Let the tool do the work; a rotary hammer needs guidance, not body weight, and pressing harder actually slows the piston mechanism down. Keep the bit turning as you withdraw it to clear dust, and for deep holes pull out every so often to empty the flutes.

Hammer only, or rotation stop (hammer symbol)

The bit stops turning and the tool becomes a light breaker. Fit an SDS point, flat chisel or gouge and use it for chasing cable and pipe runs into walls, lifting floor tiles, hacking off render or plaster, cutting out bricks and general light demolition. Most three-mode drills also have an intermediate setting (often marked with a chisel and an arrow, or called Vario-Lock) that lets you rotate the chisel by hand to the most comfortable working angle before it locks.

The other controls

Safety clutch: every decent rotary hammer has a torque-limiting clutch that disconnects the drive if the bit jams on rebar or a flint, stopping the tool wrenching your wrist. Premium models add electronic kickback control that kills the motor if the body starts to spin. Variable speed: the trigger usually controls speed; start holes slowly for accuracy. Some machines add a speed dial for matching bit diameter. Forward and reverse: reverse helps free a stuck bit and lets you drive fixings with an adaptor. Depth stop: the rod on the side handle sets a repeatable drilling depth for anchor holes, which matters because plugs and resin fixings specify one.

Which drills have which modes?

Nearly all corded and cordless SDS-Plus drills offer all three modes, though a few two-mode models drop the chisel setting, and SDS-Quick drills have no chisel mode at all. SDS-Max machines split into combi hammers (drilling plus chiselling) and dedicated demolition hammers with no rotation. Every product page on this site lists the modes under key features, and our buying guide explains what else to look for.