The Difference in SDS Max & SDS Plus

How an SDS Drill Works

• All power drills have a chuck that holds the drill bit in place. In many drills, the chuck moves back and forth with the drill bit. On SDS drills, the chuck remains stationery and the drill bit moves back and forth inside the chuck. This configuration increases power and decreases wasted motion, enabling SDS drills to cut into concrete and stone. The power of an SDS drill is measured in impact speed, shown as beats (or blows) per minute (BPM). The speed of an SDS drill is measured in revolutions per minute (RPM).

SDS-Max Rotary Hammers

• SDS-Max rotary hammers are large drills used for big jobs like demolition and heavy-duty chiseling and drilling. SDS-Max rotary hammers can operate in two modes: rotary hammer (hammering and drilling) and hammer only.

SDS-Plus Hammer Drills

• SDS-Plus hammer drills are smaller drills used for more basic drilling and chiseling. Their lighter weight and smaller size make them suitable for overhead work and for work in smaller areas. SDS-Plus drills can operate in three modes: hammer and rotation (hammering and drilling), hammer only and rotation only (drilling only). Many SDS-Plus drill models provide a "Rotation On/Off" button or switch so you can use the drill as a power chisel.

SDS-Max Drill Bits

• The shank of each SDS drill bit, the part that connects into the drill chuck, is standard for each SDS series. Each SDS-Max drill bit has an 18 mm shank with three grooves and connects to the drill chuck by locking segments. SDS-Max drill bits only fit SDS-Max rotary hammers. Adapters are available to allow SDS-Plus drill bits to fit these drills, but this tool combination may not work as efficiently as using SDS-Max drill bits. SDS-Max drill bit styles include tipped point, stubby point, masonry, concrete, wide chisel, gouging chisel and cutter.

SDS-Plus Drill Bits

• Each SDS-Plus drill bit has a 10 mm shank with two open grooves and two closed grooves, and connects to the drill shank by ball bearings. SDS-Plus drill bits only fit SDS and SDS-Plus hammer drills. SDS-Plus drill bit styles include tipped point, stubby point, masonry and concrete chisel.