Selecting the Correct Shank Type for Your Rotary Hammer Drill
When working with a rotary hammer drill, one of the most important things to consider is the type of chuck system your drill has. Knowing the chuck system of your drill is important because this determines the diameter of the drill bit shank, as well as the types of grooves that interlock the drill bit into the chuck of the drill. There are three major chuck / drill bit shank types available: SDS & SDS-Plus, SDS Max, and Spline. SDS and SDS-Plus shank types are completely interchangeable. The diameter of the shank and types of grooves will remain the same for each of these shank types regardless of the diameter, length, or other features the drill bit may have. Read on to learn more about each of these different chuck / shank types available to you.
SDS chuck systems were specially designed for concrete and masonry hammering. The flat end of the drill bit is the only part the piston will hit, which makes its energy usage more efficient and effective. One of the most convenient features of the SDS system is the ability to change the drill bit with only one hand. SDS chucks have spring-loaded balls designed to fit and lock into the grooves of the SDS shanks. After inserting the bit into the chuck, a simple twist will allow those spring loaded balls to snap into place and hold the bit. In German markets, SDS stands for “Steck, Dreh, Sitz” (Insert, Twist, Stay). The SDS-Plus shank came along when improvements were made to the original design, the SDS-Plus system allows the shank to be held in place more firmly. SDS-Plus shanks have four indentations on them: two open-ended and two close-ended, these keep the bit from coming loose from the chuck.
- SDS and SDS-Plus shank types are completely interchangeable
- Typically used with Carbide Drill Bits 5/32” – 1-1/8”
- Thin wall Carbide Core Bits up to 4”
- SDS-Plus systems are the most common since they’re adapted for relatively less-heavy drilling
- SDS & SDS-Plus shanks have a diameter of 10mm
The SDS-Max chuck system was initially designed to replace the Spline drive for larger bits, but improved connectivity similar to the SDS & SDS-Plus systems. The SDS Max system allows the piston to travel farther and in turn, allows the piston to hit the bit harder and the bit cuts more efficiently. The SDS Max system was designed for heavier-duty work than the SDS-Plus system. SDS Max bit shanks have five indentations on them: three open-ended and two close-ended, these keep the bit from coming loose from the chuck.
- SDS Max bits are only compatible in SDS Max chuck systems
- SDS Max bit sizes lean more toward the larger end of masonry drill bits
- Typically used with Carbide Drill Bits 1/2” – 2”
- Thick wall Carbide Core Bits up to 4” (thin wall up to 6”)
- SDS Max system is the newest and overall best system for the heaviest masonry drilling out there
- SDS Max shanks have a diameter of 18mm
Spline chuck systems are designed for the heaviest drilling workloads, like the SDS Max system, but the Spline is just an older system. The Spline shank has 12 “teeth” or splines that fit into the chuck and is held in place by a retaining pin. These shanks are held to an exact tolerance to assure a perfect fit. Despite the advantages the SDS Max system may have over the Spline drive, many users still prefer to use it. The primary advantage the Spline shank offers is its maximum drilling torque.
- Spline drive bits are only compatible in Spline drive chuck systems
- Typically used with Carbide Drill Bits 1/2” – 2”
- Thick wall Carbide Core Bits up to 4” (thin wall up to 6”)
- There are also a number of chipping, chiseling, bushing, cutting and digging bits available
- Spline shanks have a diameter of 19mm
