Why use SDS+/SDS Max Hammer Drill Bits?


Do you know what SDS actually means?

Apparently there are a number of claims for what it actually stands for, but the commonly most accepted is ‘Slotted Drive System’, although with its German background, it is probably most likely to originate in the phrase ‘steck, dreh, sitzt’ which translates as ‘insert, twist, fits’. So, the ‘Slotted Drive System’ means that SDS drill bits have slots at the end of the shank which fit into the chuck of the SDS drill.

These slots allow the bit to be pushed forward by the hammer action of the drill, whilst being retained by the drill due to 2 sprung ball bearings that lie in the slots of the drill bit. This is different to the standard drill chuck system where three arms grip the round drill bit.


SDS+ shank on the left and standard on the right.

So what is the benefit of using an SDS drill bit?

Well, as the hammer action of the SDS+ drill is driven by the piston firing the drill bit forward and pulling it back, there are a number of benefits. These include:

·         Increased strength of the hammer action of the drill

·         Reduced friction inside the drill

·         More efficient use of energy

·         No need to lean in hard on the drill to get it to work efficiently

What is the difference between SDS+ and SDS Max?

SDS Max drill bits are for larger applications and are much larger than SDS+ drill bits. They are considered the ‘heavy duty’ alternative and used largely for big construction masonry/concrete work. They are not compatible however with SDS/SDS+ bits.

DART offers a wide range of SDS+ and SDS Max bits. In fact the SDS+ range includes over sixty sizes and offer excellent wear resistance for drilling in masonry, concrete and hard materials. The carbide tip with special centring point boosts accurate drilling while the toothed carbide tip guides the drilling dust directly into the flute. The SDS Max Drill Bits have an X-form 4 carbide tip, making it suitable for re-bar.

To find out more, visit:  https://www.darttoolgroup.com/sds-drill-range