What does Sds mean?
This is a common quiz, asked by a Diy novice. To make matters worse there are three types of these drills available: Sds Plus, Sds Top and Sds Max. This narrative provides a basic grounding in what the Sds theory is, where it originated and what part of the theory you might be curious in.
Drill Press Chucks
Origins of the Sds System
Bosch invented the Sds drill theory in 1975. Bosch advertise Sds internationally as meaning special Direct System, though in German speaking nations it is more regularly known as Spannen Durch System(meaning "clamping system").
Types of Chuck Available
There are three standards available:
- Sds Plus is the smallest of the three and is a very common fitting for pro and Diy use. The tool's shank is 10mm and inserts 40mm into the chuck. It is rated for hammers up to 4kg.
- Sds Top is the least common of the three standards. It uses a 14mm fitting that inserts 70mm into the chuck. Sds Top is rated for hammers in the 2kg to 5kg range.
- Sds Max is a very common market fitting. Sds Max employs an 18mm shank with three open grooves and a locking mechanism, instead of the two rolling balls employed in Sds Plus and Sds Top. The shank inserts 90mm into the chuck. Max is rated for hammers over 5kg and is a common fitting for light market use.
How Does Sds Work?
All Sds tools have a cylindrical shank with various grooves down the sides. On Sds Plus and Sds Top bits there are small grooves to provide rotary force and two complete channels for a ball roller to fit into. The ball roller allows the bit to move back and forwards freely whilst under hammer action. Sds Max employs three ball rollers.
Sds Plus tools are fitted by pressing the chuck backwards towards the body of the drill and inserting the bit. Dismissal is carried out in a similar fashion. Sds chucks are keyless.
Advantages of Sds
- Quick replacement of tools
- No chuck key required for tool exchange
- Improved hammer action compared to normal varieties
- Rotation Stop or Hammer Only action enables versatile use
Disadvantages of Sds
- Cost of tools is higher than normal fittings
- Chuck requires quarterly lubrication
- Chuck must be kept clean internally else damage can ensue
In Conclusion
The Sds theory gives modern power tools a versatile edge over older competitors. Sds tools are ordinarily more mighty than their conventional cousins. Although bits used in the theory are more expensive they are long lasting and durable, regularly being tipped with tungsten carbide (Tc) or similar material to give longer life.
Sds Plus is a very common fitting for power drills used by both professionals and serious Diy enthusiasts. Sds Top is an uncommon fitting and this may or may not be an issue to your buy choice. Sds Max is regularly a light market fitting only as it is used with hammers rated over 5kg. Hammers as this rating are regularly used for light demolition work.
What is the Sds System?