What is the difference between SDS and HSS drill bits?

Posted by John Rennie on

There are two schools of thought as to what SDS stands for – either it is slotted drive system, or it comes from the German ‘stecken – drehen – sichern’ – translated as ‘insert – twist – secure’.

Whichever is correct – and it could be both, SDS refers to the way in which the drill bit is attached to the drill. It is the term used to describe the shank of the drill bit – the shank refers to the portion of the drill bit that is secured into your piece of equipment. There are four types of SDS drill bits that we will describe in more detail later.

HSS stands for high-speed steel, which is the material used to make the drill bits. HSS drill bits also have four different shanks shapes – straight, reduced, tapered, and morse taper.

What is the difference between HDD and SDS?

The difference between the HSS and SDS drill bits refers to how the drill bit is chucked or fastened inside the drill.

HSS drill bits are compatible with any standard chuck. A HSS drill has a circular shank inserted into the drill and is kept in place by three jaws that tighten around the shank.

The advantage of HSS drill bits is that they are more widely available and can be used in a much wider variety of applications. The main disadvantage is that the drill bit is prone to becoming loose. During use, the vibration loosens the chuck which means that the operator needs to pause and check the fastening, which can have an impact on job completion times.

The SDS drill bit does not need to be tightened. It can be simply and smoothly inserted into the SDS hammer drill’s designated slots. During use, the slot system protects against any vibration to maintain the integrity of the fixing.

What are the most common types of SDS drill bits?

The most common types of SDS are: 

  • SDS - the original SDS with slotted shanks.
  • SDS-Plus - interchangeable with regular SDS drill bits, providing a simple improved connection. It has 10 mm shanks with four slots that hold it more securely. 
  • SDS-MAX - SDS Max has a larger 18mm shank with five slots used for bigger holes. It is not interchangeable with the SDS and SDS PLUS drill bit. 
  • Spline - It has a larger 19mm shank and splines that hold the bits tighter. 

Rennie Tools has the full range of SDS drill bits offering superior performance. For example, its SDS Pus masonry hammer drill bits are manufactured using a heavy-duty strike-resistant tip made of sintered carbide. They are ideal for drilling concrete, blockwork, natural stone, and solid or perforated bricks. Use is fast and convenient – the shank fits into a simple spring-loaded chuck with no need for tightening, allowing it to slide back and forth like a piston during drilling. The non-circular shank cross-section prevents the drill bit from rotating during operation. The hammer of the drill acts to accelerate only the drill bit itself, and not the large mass of chuck, making the SDS shank dill bit much more productive than other types of the shank.

The SDS Max Hammer Drill bit is a fully hardened hammer drill bit, giving one of the best performances available on the market. The drill bit is finished with a tungsten carbide cross tip for the ultimate in precision and power. Because this SDS drill bit will only fit into drill machines with an SDS max chuck, it is a specialised drill bit for heavy-duty applications on granite, concrete, and masonry.

Best applications for HSS drill bits

HSS drill bits are more interchangeable across a wide range of applications. Improved performance and quality are achieved through the addition of different compounds to give superior performance. For example, the Rennie Tools HSS Cobalt Jobber Drill Bits are manufactured from M35 alloyed HSS steel with 5% Cobalt content, making them harder and more wear resistant. They provide some shock absorption and can be used in handheld power tools.

Other HSS Jobber Drills are finished with a black oxide layer as a result of steam tempering. This helps to dissipate heat, and chip flow and provides a coolant property on the drilling surface. This everyday HSS drill bit set provides the highest quality performance for everyday use on wood, metal, and plastic.

The question is not “What is the difference between SDS and HSS drill bits?”. The question that should be asked is “What is the best type of drill bit you can use for the job I have to do?” If your job is heavy-duty, using highly durable materials, which will need power and precision, then the SDS range of drill bits would be more appropriate. For lighter, more everyday jobs, the more convenient HSS drill bits will do the job extremely well. Making sure you choose the best drill bit for the job will ultimately save you time and money. If you’re still unsure as to which is the best drill bit for you, email us at esales@rennietool.co.uk or give us a call on 0161 477 9577.


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