The difference between SDS, SDS Plus, and SDS Max

Drills might not be the most exciting of subjects, but if you’re a keen DIYer, at some stage you’re probably going to end up giving a considerable amount of thought to whether that basic hammer drill you’ve had for years is really up to those heavy-duty jobs such as drilling into walls or hardwood.

In practice, for many common jobs around the home, it’ll work just fine. However, if you want to accomplish tasks more efficiently or are planning on going up a gear and tackling something along the lines of drilling larger holes in masonry, breaking up tiles at speed, or even working with solid stone, it could be time to consider investing in an SDS drill.

As a pretty serious piece of kit often used by professionals, SDS drills usually don’t come cheap. To complicate matters further, there are several different types available including the original, plain old SDS, SDS Plus, and SDS Max. So you’re going to need to familiarise yourself with what’s out there before parting with any of your hard-earned cash.

Here, then, is our handy introduction to the various classes of SDS drills to help get you started.

What is an SDS drill?

Introduced by German manufacturing giant Bosch back in 1975, the SDS drill was essentially developed as a quick-release hammer drill. Incidentally, the acronym originally stood for ‘Stecken – Drehen – Sichern’, translating as ‘Insert – Twist – Secure’. This was adapted to ‘Special Direct System’ for the international market, however, some retailers now substitute this for the phrase ‘Slotted Drill System’ to give the drills a more explanatory title.

Instead of relying on those pesky chuck keys which are so easily lost in the depths of your toolbox, garage, or garden shed, these clever devices use a specially designed bit and chuck combination which employs corresponding slots or grooves to lock together via a firm pressing motion. The two components can then be separated similarly as necessary.

This enables the user to switch bits at speed, thereby accomplishing complex tasks with maximum efficiency and minimum effort. As the technology began to evolve, additional features were introduced such as the ‘rotary stop’ function. Preventing to drill from rotating leaving just the forward-back hammer motion, this effectively converts the drill into a heavy-duty, automated chisel.

What is SDS Plus?

Featuring the same 10mm shank size and compatible with the original SDS bits, SDS Plus drills are a refined version of the earlier models. These updated drills feature more power and an improved chuck mechanism and have now largely superseded the earlier SDS models. However, as a low-cost option, it is still possible to obtain an older, pre-SDS Plus unit.

What is SDS Max?

As the name implies, SDS Max drills are designed to be used for the heaviest applications such as breaking up masonry or even full-blown demolition work. They feature a more complex slot system for added stability and offer the user even more power compared to the SDS Plus models. To accommodate this, SDS Max drill bits have a larger shank which measures 18mm in diameter. As a consequence, bits are not interchangeable between SDS Plus and SDS Max drills.

What about SDS Top?

The SDS Top was broadly a precursor of the SDS Max which was designed for use with concrete and masonry. It features an elongated chuck unit to accommodate longer bits. However, the SDS Top was rendered more or less obsolete with the introduction of the SDS Max, and while compatible buts are still available it is now being gradually phased out.

Can I use an SDS bit in a standard drill?

While is possible to use an SDS bit in a standard drill this is not recommended over time this may compromise the functionality of the bit when used with SDS drills. This is because even minimal wear to the slots may compromise the efficiency with which they interact with the corresponding indentations in the chuck, especially at high speeds.

What range of SDS drill bit sizes are available?

SDS drill bits are available in lengths of up to 1500mm. At the other end of the scale, the shortest SDS drill bits measure just 110mm. In terms of diameter, SDS drill bits range from 5mm up to 100mm. This impressive range of sizes is an important factor in achieving the incredible versatility SDS drills can offer.

What types of SDS drill bits are available?

Another element that makes SDS drills so versatile is the impressive range of compatible drill bit types which are available. These include everything from basic masonry bits which function in much the same way as a standard equivalent, to extremely long bits primarily intended for industrial applications, to large diameter bits capable of drilling wider holes in tough materials such as concrete or stone.

One specific example is the SDS Plus-3 drill bit. These feature a fluted design for optimised dust removal and endurance when drilling into hard masonry or concrete. A good place to start is to buy a basic set of SDS bits which will include a section of the most commonly used types.

Is there anything else I need to know?

Hopefully, we’ve covered the basics, but if you want to get a feel for what the various types of SDS drills have to offer and which would be most suited to your own needs, your best course of action is to purchase a starter kit. This will include an SDS drill (most likely an SDS Plus), together with a broad selection of bits and accessories.

There is a strong used market for SDS drills, so you should easily be able to sell on should you decide to upgrade to something with more power or specialist functionality once you are familiar with the technology and how to operate it.

Whether you decide on just an affordable basic SDS drill, an SDS Plus, or even if you decide to go for the formidable bruiser that is the SDS Max, these impressive bits of kit often prove to be a real game-changer for even the most experienced of DIYers. So as it turns out, this whole drill business isn’t quite so boring after all.



image credit: “First Look at the Bosch GBH3-28DFR SDS P” (CC BY 2.0) by toolstop


Leave a Reply

Your email address will not be published. Required fields are marked *