The Ultimate Guide to SDS Drill Bits: Types, Uses, & Buying Guide
If you are in the market for SDS drill bits, this blog post is a must-read. SDS bits are versatile tools that can be used in many different masonry materials. This article will outline what SDS drill bits are and discuss the different types of SDS bits available on the market today. We'll also go over which SDS hammer drills should be used as well as offer some tips on buying SDS bits for your next project!
In this blog we'll cover:
- The differences between SDS bits
- A buying guide for SDS bits and your project
- Dustless or Hollow drill bits
- What rotary hammers work with which bit
- The origins of SDS bits
What's the Difference Between SDS Plus and SDS Max?
While SDS and SDS-Top bits are much less common and SDS-TE-S bits are mostly for chiseling and demolition applications, SDS Plus and SDS Max are probably why you're here. So what's the difference?
Physically there are size differences in the masonry bits. SDS Plus have a 10mm shank, while the SDS Max has an 18mm. This means that SDS Max bits have an increased capability for tougher masonry work, withstanding more torque and force.
The SDS Plus range is shorter in length and is tailored to lighter duty work and smaller diameter holes. Don't relegate them to a household duty bit. Sometimes you will need to use an SDS Plus bit when the job doesn't demand a larger hole or when you're working close to the edge. Especially when working close to the edge, a smaller, less powerful drill is preferable because it reduces the risk of chipping off a piece of concrete from an outside edge.
You'll find SDS Max have much longer lengths for deeper embedment. There is some overlap between the two but SDS Max are generally designed for more demanding, deeper drilling applications.
The SDS-Max variation has been created to have an improved torsional strength which means that it can be driven at higher speeds and still maintain its force without breaking. When drilling into concrete, bits will inevitably encounter more resistance due to rebar and aggregate that are densely packed in. This is where having a higher torque and increased force will save you time.
A versatile drill bit, you would use a SDS Max bit when you have a larger stud that needs to be embedded deep or when drilling through thicker substrates. For example, when you have to drill through a wall for a conduit or wiring.
When you're buying masonry bits, consider the different types that are available and look for one that fits your application. Don't just go buy one because it's cheaper.
Buying Guide: What should I look for?
SDS masonry bits are most commonly used in post-installation of anchors in concrete construction and masonry applications such as stone or brick. If you work as a trades professional, there are advantages and disadvantages to using different SDS drill bits.
Before you purchase your SDS masonry bits it's important to make sure they're compatible with your current drill. Another consideration to make is the application. What diameter hole are you drilling? What are you drilling into? Concrete, stone, brick? Are there concrete dust dangers? These questions can be absolutely paramount to the success of your project. Once you have these under control, you can move onto your bit types and features.
There are key features to look for when selecting any SDS bit. Including:
- Carbide tips
- Tip design
- Flute amount and design
- Dustless drill bits
SDS bits undergo some serious pressures and friction when drilling, generating heat and affecting the integrity of the bit. That's why our SDS bits use tungsten carbide.
Tungsten carbide-enhanced SDS drill bits are approximately twice as stiff as steel and effectively shed heat. The tip material maintains a sharp cutting edge better than steel tools, allowing for a smoother finish and efficient material removal.
Other brands often can use titanium carbide which while harder, doesn't shed heat as well. It's thermal conductivity is much higher than tungsten carbide, which will bleed into the rest of the steel bit, reducing it's working life.
As most masonry bits will have different tips, their integration into the steel flutes and spline vary amongst brands. Key design features to look for will be if the tip is welded or inserted. But what's the difference?
Welded tip designs have faster performance in material removal thanks to the flutes being closer to the tip. Inserted or recessed tips can stay sharper for longer, but are often only used for softer materials. Insert tips will leave more dust that will mean more cleaning and brushing out the hole.
The next thing to look for is the tip layout. Various SDS bits will have:
- Crossed tips that can provide more performance through rebar, but leave more dust. Bits with cutting tips attached to the flutes extract concrete dust more efficiently than those with crossed design.
- Chamfered rebar carbide tips balance the efficiency needed to demolish through rebar and the working life of the bit. Always look for chamfered tips to increase the use you get out of the bit.
- Multi-cutter or Y-cutter bits are often found on dustless drill bits to efficiently move dust into the vacuum holes. But they can also be found on SDS Plus and SDS Max bits. On standard bits these designs can not be as useful due to their inserted tip design.
Flute Amount & Design
Flutes run up the shaft to the spline to remove dust efficient and prevent clogging of the tip. A large distance between tip and flute can prove detrimental but so can the flute amount and design.
The amount of flutes are typically defined by the tip design. The more flutes you have, the more material will be removed at a fast pace. However, it's important to note that both too many and too few flutes can cause problems. Bits with 3 to 4 can be the best compromise for drilling into concrete and masonry.
Higher flute design, that is flutes with a less rotations, allow for greater dust removal while shallower and tighter flutes can be prone to clogging at the tip. Shorter flutes require less pressure while drilling but don't remove as much material which will slow down the job at hand.
Dustless or Hollow Drill Bits
Dustless drill bits get their own special mention. New on the market, dustless drill bits use their tips and holes to draw the dust away from the bit and into a vacuum pathway as your drilling. This allows for cleaner working conditions and more efficient drilling, especially when concrete silica dust is of concern.
The vacuum holes is an up-to-date solution to an age old problem of concrete dust clogging drill holes usually leaving incomplete holes. The vacuum holes draws the dust past the bit, leaving clean and clear drill holes. Used in chemical anchoring applications, dustless drill bits can eliminate the need to blow and brush holes before injecting chemical anchors.
Dustless drill bits can also reduce exposure to crystalline silica, commonly referred to silica dust. Silica dust is released from masonry materials when crushed, drilled, sawed, or polished. The fine particles from masonry that slip into the respiratory system can have catastrophic health outcomes, causing incapacitating and debilitating health conditions with high exposure. Dustless drill bits help as an engineered control as the extract the silica laden concrete dust before it becomes airborne.
Dustless drill bits come in both SDS Plus and SDS Max with many tip designs. Regardless of the type of drill bit, these bits are efficient and leave little to no room for error when drilling and anchoring.
Which SDS bit should I use?
When working with masonry, both SDS Plus and SDS Max tools are equally capable of getting you the results you want. An SDS Max bit is can be hard hitting and powerful tool to get the job done. But may not have the finesse on finer, closer to the edge drilling.
You now know all the key factors involved with SDS drill bits and selection. The most important takeaway is to consider the task at hand and using the facts we've outlined to make your choice. And if you're going in blind to a job, then it’s better to be overprepared than underprepared on site. In many cases, it might mean an easier drilling process and faster result; and that is never a bad thing.
We created this tactical SDS bit guide to help you choose the best SDS-Plus and SDS-Max bits on the market. And if you have any questions about the facets raised in this article, reach out to us. One of our customer service or sales representative will be happy to handle your question and drill down to the product you need to get the job done.
Are all SDS Drill bits compatible with a Rotary Hammers?
The bad news is no, you'll need a different power tool with an SDS chuck for different bits. Older SDS bits will fit into the same drill as SDS Plus bits, but will require a SDS Plus hammer drill. And SDS Max bit require there own SDS Max hammer drill. The size of the shank prohibits each bit being compatible with another rotary hammer drill. So it's important to think about your task at hand. Look at the job and consider:
- What am I drilling into? Is it harder concrete or maybe stone?
- What size hole is required? What depth do I need?
Regardless, whether it's an SDS Plus or SDS Max bit, when it's is inserted into a hammer drill, all you have to do it just insert it and it will stay put with its shank design preventing the bit from wiggling loose. Rotary hammer drills fitted with an SDS chuck are spring loaded. Its as simple as insert, twist, and it's secure. As it was designed by Bosch, back in 1975.
The splines on the side of the SDS bits allow for movement along the shaft, enhancing the hammering action. As the bit turns and gouges the concrete, the pulverising movement pushes the SDS bits further into place.
Power drills with the hammer function are capable for use in softer masonry materials like brick or hollow block. But their 3 jaw chuck is their Achilles heel. If a power drill encounters resistance while using a smooth shank drill bit, the risk of the drill bit slipping increases. You'll lose traction and more importantly, time. As a tradesperson, use the right tool for the job. Rotary hammer drills.
The biggest take away when choosing your rotary hammer is speed and the amount of hammer actuations per minute. It can mean the difference between a two minute job that turns into a 15 minute job with an underpowered drill.
Origins of SDS
Drilling concrete or stone with a standard drill is nearly impossible, but SDS drills and bits have proved to be the answer. After three decades of development in Germany, this new form of drilling has been used all over the world for many different types of work.
Using standard drills and drill bits required users to tighten the three jaws around smooth the shank. The problem was as soon as the drill bit encountered any resistance, the drill bit stalled in the chuck and would require retightening. Often causing frustration and slowing down work. Something had to be done.
What was needed was a fast drill bit interchanging system that was both secure but allowed for some movement vertically in a rotary hammer drill. Where other had tried using spline bits in their development, it was Bosch who came through with a reliable product. This is where German ingenuity comes in to develop the original SDS bit. SDS Plus and SDS Max would come later.
One of the major features that distinguishes SDS from other types is how it sits in your power tool. Whereas regular bits usually are secured with the 3 chuck jaws, an SDS bit has slots to connect it and tightly turn with accuracy and speed.
Developed in the 1970's, the original meaning for SDS was Stecken – Drehen – Sichern which when translated to English is "Insert – Twist – Secure". The action that you typically make when insetting a bit.
SDS Bits Today
Today, SDS stands for "Slotted Drive Shaft" and it has had many iterations over the years with different variations. One fantastic feature of SDS bits is that they don’t spin inside the drill when in use. There are a number of SDS bit types that you might find yourself using:
The simple and original SDS bit has been out of production for years, with SDS-Top bits being phased out with other models taking it's place. SDS-TE-S bits are generally chisels or scrapers used for chiselling or demolishing concrete applications compatible with 'jack hammer', aka demolition hammers. These days the most common SDS masonry bits you'll encounter on site are typically the SDS Plus and SDS Max variants. These are your typical concrete bits whether it's dustless, 3 flute, welded tip and so on.