Cross-section of SDS drill bit shanks
Modern hammer drills today typically use the SDS system of drill bit attachment developed by Bosch and Hilti in 1975. Other hammer drill bit systems do exist but the SDS system seems to have taken hold amongst tradesmen and DIY-ers alike leading to it becoming the dominant type the world over. Today, three different SDS formats exist that are non-interchangeable, SDS Plus, SDS Max and SDS Top.
SDS Plus vs SDS Max vs SDS Top
SDS Plus
SDS Plus accepts a 10mm diameter shank (the part of the drill bit that attaches to the chuck) and is the most common type of SDS used. Designed for hammer drills up to 4kg, it is capable of handling the majority of building work needs and so has become the most common type.
The SDS Max system uses an 18mm diameter shank and is designed for larger hammer drills (5kg and more) best used for more aggressive drilling.
The SDS Top specification whose characteristics partially overlap those of both SDS Plus and SDS Max drills is not very common and is slowly fading from use. In fact, you would be hard-pressed to find an SDS Top specification drill for sale in today's market so we will ignore it in this review.
Furthermore, we are pretty much going to be focusing here on SDS Plus drills only since they are the dominant type of impact drills on the market today and, in reality, unless you need the extra high drilling power for a specific job that an SDS Max drill affords, you are typically going to be buying an SDS Plus hammer drill.
What to look for in an SDS Hammer Drill
Cheap Muscle vs Refined Quality
In the table below you will find some of the most popular corded SDS Plus hammer drills available in the UK at the present time. In general, SDS Plus hammer drills fall into two broad categories, the less well-known, less expensive, fewer 'bells & whistles', and heavier drills (the Wolf, Silverline, and the Terratek), and the brand-name, more expensive, more universal, better-made, and lighter hammer drills of Bosch, Makita and other well-known power tool manufacturers. So one of the first decisions that is best made when purchasing a new SDS hammer drill is to decide on which of the two categories is more important to your purchasing decision.
Maximum Speed
The maximum revolutions per minute or RPMs that a drill can accomplish will be mainly determined by what sort of work the drill was designed for. Lower speeds are used to penetrate harder materials such as masonry, while higher speeds are used for softer materials like timber. As a result, many of the drills designed exclusively for masonry work will have lower overall maximum speeds, while more multi-purpose hammer drills that can also be used to drill timber and metalwork will have higher overall speeds usually with some form of speed control integrated into the design.
Blows Per Minute (BPM) and Impact Energy
These are important parameters for hammer drills as they determine how easily masonry is drilled and chiseled. The higher the BPMs and the higher the impact energy of each blow, the easier it will be for the drill to make its way through the masonry. If the drill has an easier time going through the material, it means the drilling will be smoother and more accurate.
Weight
Weight of the drill is an important characteristic for hand drills. If you are going to be working with the SDS hammer drill (especially a corded one) above shoulder level or for extended periods of time, having a lighter drill is best while a very heavy drill will become inconvenient in a hurry. Even some of the lighter-weight hammer drills (2-3 kg) can become bothersome when used in an elevated position, so you can just imagine what working with a 6kg drill will feel like (that's assuming that you are of sufficient physical stature to manipulate the drill in the first place!)
Common Features
SDS hammer drills also tend to come with some common features too, such as multiple modes of operation. These days almost all hammer drills have the ability to switch off the rotary or the hammer action of the drill, typically providing the user with three modes of operation:
- Rotary action only (for drilling into wood, metal and plastics)
- Rotary hammer action (for hammer drilling into masonry, concrete and other hard materials)
- Hammer action only (for use as a power chisel)
Another common feature of hammer drills comes in the form of their safety characteristics. In the interests of user safety, and since today's hammer drills generate such high levels of torque, corded SDS hammer drills almost always include a slip-clutch or torque limiter to prevent loss of control of the drill and potential user injury in the event of drill bit binding. The slip-clutch or torque limiter 'detaches' the rotary action of the drill bit from the drill motor if the drill bit jams in the substrate while drilling and thus prevents the whole drill rotating around the stuck drill bit potentially injuring the operator.
Popular Corded SDS Hammer Drills in the UK
| SDS Hammer Drill | Max Speed (rpm) | Blows Per Minute (bpm) | Impact Energy (Joules) | Motor Power (Watts) | Weight (kg) | |
|---|---|---|---|---|---|---|
Bosch PBH 2100 RE |  | 2300 rpm | 5800 bpm | 1.7 J | 550 W | 2.2 kg |
| Bosch GBH 2-20 D |  | 1300 rpm | 4200 bpm | 1.7 J | 650 W | 2.3 kg |
| Evolution SDS4-800 |  | 1100 rpm | 5000 bpm | 1.6 J | 650 W | 2.8 kg |
| Makita HR2610 |  | 1200 rpm | 4600 bpm | 2.4 J | 800 W | 2.8 kg |
| Makita HR2630 |  | 1200 rpm | 4600 bpm | 2.4 J | 800 W | 2.8 kg |
| DeWalt D25133K |  | 1500 rpm | 5500 bpm | 2.6 J | 800 W | 2.6 kg |
| Bosch GBH 2-26 |  | 900 rpm | 4000 bpm | 2.7 J | 830 W | 2.7 kg |
| Hitachi DH26PX |  | 1100 rpm | 4300 bpm | 3.2 J | 830 W | 2.8 kg |
| Silverline 633821 |  | 800 rpm | 4000 bpm | 3.5 J | 850 W | 4.9 kg |
| Einhell RT-RH 32 |  | 800 rpm | 4300 bpm | 3.5 J | 1250 W | 6 kg |
| Terratek 1500W |  | 800 rpm | 4000 bpm | 5.5 J | 1500 W | 4 kg |
| Wolf 1500W |  | 900 rpm | 3900 bpm | ** | 1500 W | 6 kg |
| Max Speed (rpm) | Blows Per Minute (bpm) | Impact Energy (Joules) | Motor Power (Watts) | Weight (kg) |
SDS Hammer Drill Reviews
Bosch PBH 2100 RE SDS+
The Bosch PBH 2100 RE has a less powerful motor than some of the other hammer drills discussed here. That's because the drill tends to be more of a universal drill rather than just a hardcore hammer drill - it even has a setting for screwdriving! - but make no mistake, the Bosch PBH 2100 RE is still a very respectable SDS Plus hammer drill as well. The maximum hole diameter that it can produce in masonry is 20mm, a more modest value than for a specialised hammer drill but still more than what most builders and home users will ever need.
To get the Bosch PBH 2100 RE to use regular drill bits or to act as a screwdriver, chuck adaptors are available for purchase separately that take [easyazon_link asin="B0009W873Q" locale="UK" new_window="yes" nofollow="default" tag="diyfidelity-21" add_to_cart="default" cloaking="default" localization="no" popups="default"]non-SDS[/easyazon_link] and screwdriver bits, respectively (see images below). Both chuck adaptors work by simply slotting directly into the SDS Plus chuck with the drill having a selector for reversing spindle rotation, an important feature for getting drill bits out of jams in addition to changing screwdriving directions.
As with a standard rotary hammer drill, the Bosch PBH 2100 RE SDS drill can also switch off its rotary motion while preserving its hammering capabilities so it can also act as a light power chisel. Unlike some of the cheaper hammer drills available, the Bosch PBH 2100 RE has rotational speed control incorporated into the trigger, so that increasing the pressure on the trigger slowly increases the speed of the drill or screwdriver bit rotation. The drill is also relatively light in weight, which is not a bad thing if you need to work with it up a ladder or above shoulder height. In fact, some of the heavier hammer drills available are near impossible to use effectively for work higher up. Finally with the Bosch brand, you can rest assured that you are buying one of the best quality SDS hammer drills available, a tool that is very well made and built to last a very long time.
Adaptor for regular drill bits
Screwdriver adaptor
Bosch GBH 2-20 D SDS+
The Bosch corded SDS hammer drill GBH 2–20D is part of Bosch’s lineup of professional power drills targeted squarely at the tradesman or professional builder. This means that the drill is more highly priced than the equivalent machine in its DIYer’s drill lineup, but for that higher price, you get a better built machine with a significant increase in robustness and longevity.
Features on the GBH 2–20D are typical of most SDS drills in this power tool category. The SDS drill is rated for rotation up to 1300 RPM with a hammering action of up to 4200 BPM (blows per minute) and a maximum impact energy of 1.7 Joules, all of which is produced from a 650W electric motor. This translates into an ability to penetrate concrete with a diameter of up to 20mm when the hammering action is engaged, or up to a diameter of 30mm in wood and 13mm in metal with the drill in regular non-hammering mode. Although the rotational speed of the Bosch SDS drill cannot be set directly, variable pressure applied to the trigger of the machine allows for variable speed control, while the drilling function mode dial, which allows the drill to function in either non-hammering, hammering, or chisel modes, is smooth and easy to change.
The Bosch SDS hammer drill weighs approximately 2.3 kg, which is average for power drills in this category, and it is available in both 110V or 240V versions to accommodate for power systems found on either larger worksites (110V) or those in the home (240V).
As for the robustness and the build quality of the Bosch GBH 2-20D professional SDS hammer drill, as alluded to earlier, this is where the Bosch machine stands out. The Bosch drill has been built to operate under heavy use with minimal downtime typical of how it is often used on a worksite.
Safety-wise, like other high-quality rotary hammer drills, the Bosch power drill has been designed with an overload clutch which immediately disengages the rotary action of the drill spindle if the drill bit becomes jammed. This protects the user (as well as the drill itself) from a violent counter-motion of the drill body in the direction opposite to the rotation of the drill bit, which could otherwise have the potential to seriously injure the user and potentially cause damage to the drill itself.
The case for the Bosch GBH 2-20D has ample space for the drill, its power cord, and accessories
As for accessories, the Bosch drill comes in a plastic carry case which makes keeping the power tool clean and organised a simple process. Even the design of the carry case is well-thought out, so for instance, even the mains power cord, which is very generous in length on the Bosch GBH 2–20D, can be easily packed into the carry case without any fuss (something that is not always true with carry cases from less reputable power tool vendors).
As for any dislikes with this Bosch professional drill, there is actually very little to say negatively about the power tool other than perhaps the lack of any drill bits included as part of the package when purchasing the drill. This is especially poignant if you are new to the SDS Plus drill ecosystem as it means you will have to invest separately in a set of SDS Plus drill bits which will just add to the overall cost of an already expensive Bosch drill.
Overall, the professional Bosch SDS drill is certainly worth its premium cost, especially if your trade requires a fair amount of drilling or you are using the drill excessively over a short period, and if you are upgrading from a regular percussion hammer drill, then you will certainly notice the improvement with the Bosch rotary hammer drill SDS Plus chuck-based hammering action.
Click here for the official webpage of the Bosch GBH 2-20 D hammer drill
Evolution SDS4-800
The Evolution SDS4-800 SDS hammer drill is a low cost hammer drill from a company whose reputation for good power tools at reasonable prices is growing.
For the price, the SDS4-800 has a remarkable level of functionality. It has the usual 3-mode function settings where it can be set to be used either as a regular drill for drilling materials like wood, a hammer drill for drilling up to 20mm diameter in masonry, or as a power chisel. However, unlike most other competitor SDS hammer drills, the chiselling function on the Evolution SDS4-800 also has the added option of being set to either a locked mode where the chisel head stays fixed in one orientation, useful for when the chiselling angle is important, or set to an unlocked mode which allows the chisel head to rotate freely as it encounters resistance (it should be noted that the chiselling action on the SDS4-800 tends to look quite weak when operated in free air, and only shows its true power when pressed against a workpiece).
The SDS4-800 also has variable speed control primarily operated through varying the trigger pressure but also facilitated by a dial on the trigger switch which allows one to set the maximum drill speed. Above the trigger switch is a reverse switch that can reverse the rotation of the drill bit to help one get out of drill bit jams. As with most SDS hammer drills these days, it comes with a safety clutch which disengages the drill bit rotation from the motor in the event that the drill bit binds while drilling, reducing the chances of injury to the operator. To top it all off, the drill also comes with an introductory set of SDS drill bits and chisels as well as a plastic carry case to hold it all together.
With all this capability, it is easy to forget that the drill is a budget tool designed for the DIYer or the professional whose masonry drilling and chiselling needs are on the lighter side. Consequently, it should be no surprise then that the Evolution SDS hammer drill tends to run hot when used for extended periods of time, especially when used in chiselling mode, and the operating manual recommends no more than 30 minutes continuous use before giving it at least as long to rest and fully cool down.
Overall, the Evolution SDS4-800 SDS hammer drill is excellent value and ideal for individuals that need to do some occasional masonry drilling or chiselling. However, if your masonry drilling/chiselling needs are more intensive, you are likely to be better off going for a more established (and more expensive!) manufacturer that targets its tools for use at the construction site.
Click here for the official webpage of the Evolution SDS4-800 hammer drill
Makita HR2610 & HR2630 SDS+
Makita HR2610
With the Makita HR2610 corded SDS hammer drill, you pay a higher price but you have the comfort of knowing you are getting a quality Japanese product. It has all the standard settings of a typical rotary hammer drill, allowing the user to also use it as a regular drill (rotary-only setting) as well as a power chisel (hammering-only setting). It can drill holes up to 26mm in masonry. For safety of the operator and the drill itself, it has a torque limiting clutch to prevent loss of control of the drill if the drill bit jams while drilling. In addition, the drill also has a reverse setting for drill bit-jamming situations. Quality on the Makita SDS drill is second to none and as expected this is reflected in the price compared to some of the cheaper hammer drills available in the UK that are less well-built. The trigger has variable speed control through the amount of pressure applied to it giving the drill more controllable and more accurate drilling capabilities. Makita power tools tend to be up there with the most expensive brands, but as the old adage goes: 'you get what you pay for' and this happens to be true with the Makita HR2610 hammer drill, which is one of the best corded SDS drills that we have reviewed so far. Makita power tools in general are precision tools that include all the latest technology and are built to last.
Makita HR2630
2018 update: Makita HR2610 vs HR2630
The HR2610 SDS hammer drill has been discontinued by Makita and has been replaced by the HR2630. Essentially the HR2630 is the same machine as the HR2610 but with one key enhancement: the operation of the mode-change switch. On the HR2610, when changing from the hammer-only action to the rotary-only mode (or vice-versa), the switch was liable to getting stuck due to the way the mode-change mechanics worked inside the drill. In order to deal with this issue, the Makita manual for the HR2610 included advice on how to change between the hammer and rotary action settings:
Excerpt from the Makita HR2610 manual
This meant that when changing between rotary- and hammer-only actions, one often had to change to the dual (rotary and hammer) mode first and rotate the chuck a little before changing to the single action mode required. On the HR2630, this slightly cumbersome protocol has been eliminated completely and the mode-change switch can now be rotated directly to any of the desired mode positions once the motor has stopped. This has made an already excellent SDS hammer drill even better!
DeWalt D25133K SDS+
No review of SDS hammer drills would be complete without looking at an SDS drill from the DeWalt brand. DeWalt is owned by the Stanley Black & Decker group which, as one might guess, manufactures and sells Stanley and Black & Decker tools targeted towards the DIY consumer. The DeWalt brand is the more premium division of the company, which consists of higher calibre tools targeted at professionals and DIY enthusiasts.
There are several SDS-Plus hammer drills in DeWalt’s lineup, catering to the needs of different building Industry practitioners as well as to specific building tasks. One of these SDS-Plus drills is the DeWalt D25133K, a more ‘everyday’ type of SDS hammer drill designed to work on a range of tasks encountered on the building site, from drilling through wood or concrete to lightweight chiselling of masonry.
The DeWalt SDS plus hammer drill is both powerful and lightweight, sporting an 800W electric motor and weighing in at a medium-level weight of 2.6 kg. Like the majority of other SDS hammer drills, it is an SDS-Plus hammer drill, meaning it can only accept SDS-Plus drill bits. However, chuck adapters are available that can convert the SDS-Plus one into a regular bit-holding chuck if so desired.
The DeWalt D25133K drill has the typical three modes of action found on most hammer drills including, drilling only (impact stop), hammer drilling, and just straight hammering action (rotation stop). This allows it to be used for drilling a variety of materials from masonry to wood, as well as for chiselling. With the appropriate drill bits, this DeWalt SDS-Plus hammer drill can penetrate up to 26mm of concrete, as well as up to 30mm of wood. It can even drill through metal up to 13mm in a pinch. The rotational speed on the drill is fixed at 1500 RPM, however, electronic variable speed control can be exerted through the trigger if slower speeds are required. In addition, the drill rotation can also be set to turn in either a clockwise or anticlockwise direction, which can be useful for the unjamming of stuck drill bits.
When in hammer mode, the DeWalt drill delivers a high 5500 blows per minute generating a quite substantial to 2.6 joules of energy with each blow, making it quite a powerful machine for its size. This is particularly well-suited for both drilling through masonry as well as chiselling. However, the chiselling action is designed for more lightweight tasks rather than the heavy-duty breaking up of masonry, where a dedicated, more heavy-duty hammer drill would be more appropriate.
From a safety standpoint, the DeWalt drill includes a mechanical clutch which protects the operator from high torque counter-rotational forces in the event the drill bit jams. The drill has also been built to last even in the harsh environment of the building site, using both high-grade robust materials for its construction as well as the inclusion of effective dust seals to keep drilling dust and debris from interfering with the internal mechanics.
The DeWalt SDS+ drill comes with the standard sturdy DeWalt carry case
Other features on the DeWalt drill have also been well-thought-out, with an electrical power cable that has a good working length, and a depth stop that can be easily set and locked into place through the use of a locking button. The drill also comes with its own standard DeWalt-branded carry case which is basic in nature but sturdy.
One notable feature missing from the drill is the inclusion of a trigger lock, meaning the drill can not be locked on when performing extended work tasks.
The overall impression of the DeWalt drill is one of quality and well-thought-out design. It has been built to last and to allow the user to work efficiently, like most DeWalt Power tools. The caveat to this is the price of the DeWalt D25133K drill, which is generally higher than most other equivalent SDS hammer drills, but then again, one tends to get what they pay for, and this also happens to be true for this drill as well.
Bosch GBH 2-26 SDS+
The Bosch GBH 2-26 SDS Plus hammer drill is a very capable machine from the Bosch professional line of power tools. It comes with an 830W motor operating at a maximum of 900 rpm, giving the drill 2.7 Joules of energy at 4,000 blows per minute. This power is enough to complete almost any job in a wide array of materials including steel, plastics, wood, stone, ceramics, and concrete. Unlike a lot of tools these days, this Bosch drill is actually made in Germany, and is backed by a brand known for performance and sturdiness.
The Bosch drill comes with a few features that show off its performance and help get building tasks completed efficiently. Firstly, the drill has built-in air cooling, allowing it to be used over prolonged periods for tougher jobs. When precision drilling depth is needed, the drill comes standard with a depth stopper, and the drill depth setting can be changed with a simple push of a button. If a drill bit gets stuck while working through a heavy-duty hammer drilling session, the Bosch comes prepared: The rotational direction switch can reverse the rotating motion of the bit, helping it become dislodged so that the job at hand can continue.
There are also a couple of additional features that make this drill user-friendly while drilling. It is equipped with a 'lock-on' button that allows the drill to operate continuously without needing to keep the trigger pressed. This feature is particularly useful when drilling or chiselling through difficult concrete. The Bosch hammer drill also comes with an overload clutch, which stops the drill bit rotation if it happens to bind. This safety feature saves the driller's wrist as well as the drill motor. To ensure longevity, a ball grommet on the power cord of the drill makes it stand up to the unwelcome breaks and snags that corded tools commonly face over time.
The Bosch Professional GBH 2-26 (the 'non-F' version) comes with an SDS+ quick-change chuck that is used with SDS+ bits for hammer drilling and chiselling. The drill can also use more standard cylindrical-shanked bits and tools if an appropriate keyed 'adaptor' chuck (not supplied; no. 17 in the below image from the operating manual) is inserted into the SDS+ tool holder. This chuck-changing mechanism should not be confused with that of the almost identical GBH 2-26 F version of the tool, which has an SDS+ quick-change chuck (no. 2 in the below image) that can actually be completely swapped out for a standard chuck (which is included with the 'F' version of the drill). This chuck-swapping mechanism makes it even easier to switch between various jobs and bit types.
GBH 2-26
GBH 2-26 F
In terms of bit sizes, the drill can take quite a wide range. For hammer drilling bits, it can take bits up to 26mm in diameter, while for concrete core cutters the drill can handle up to 68mm in diameter. Metal drilling bits can be up to 13mm wide, while wood-drilling bits can be up to 30mm in diameter.
As with other rotary hammer drills, the Bosch machine has a variety of settings for different needs. It has a hammer drilling position, which allows it to drive and cut into concrete and stone. The standard drilling position is for straightforward drilling and screw driving into wood, metal, ceramic and plastic. And a chisel setting with a handy Vario-lock mode that is used for locking the chisel head into one of 36 different positions for the perfect chiselling angle.
The drill comes in a hard carry case, with ample room for the drill, its cable and an assortment of bits. It is also supplied with the standard auxiliary handle for hammer drills, giving better control during tough jobs.
Overall, the Bosch GBH 2-26 SDS+ rotary hammer drill is a versatile tool for use in a variety of jobs from simple drilling to construction demolition. It can handle long continuous use and make it easy for the person using it to last as well! This Bosch drill can chisel and bore through almost any building material and is built to last. It is a solid choice for the serious DIYer or professional looking for their next rotary hammer drill.
Silverline 633821 SDS+
The Silverline 633821 SDS hammer drill is another reasonable piece of kit from the Silverline Tools company but professionals beware: this is not a tradesman's tool and excessive use can overwork the drill to the point of failure.
Feature-wise, the Silverline SDS drill sports an 850W motor that runs at a standard 800 rpm, similar to other heavy SDS drills in this hammer drill category. With hammer drilling turned on, it produces 4000 bpm and a reasonable 3.5J of energy with each impact. Under this specification, the Silverline SDS drill can drill up to 26 mm diameter holes in masonry, assuming that one is drilling into brick or normal concrete mixtures, as the Silverline drill may struggle with harder concrete formulations. As with the majority of today’s SDS drills, the Silverline machine can also be used as a normal rotary-only drill when the hammer function is turned off, which is mainly useful for drilling wood or steel. Similarly, when the rotary function is inactivated, the drill can also be used as a power chisel.
A standout characteristic of the Silverline drill is that it is a relatively heavy machine coming in at approximately 4.9 kg. Although its heavy weight can be a negative for operator fatigue or for just carrying the drill around, it can also act as an advantage in some situations especially when using it to break up masonry.
The Silverline drill comes with a case
Accessories-wise, the Silverline drill comes with everything you need to get started. This includes a small selection of SDS drill bits, a normal 13 mm keyed chuck for regular (non-hammer mode) drilling, a pot of grease, and spare carbon brushes for the electric motor. It also includes a plastic carry case to keep the bulky drill safe when storing or transporting it.
Although the inclusion of these accessories may appear to give the Silverline drill a value advantage over other more costly drills where you have to buy the accessories separately, the accessories that come with the Silverline drill are not of the highest quality and can sometimes cause more problems than they are worth. For example, the drill bits that come with the machine can too easily become twisted out of shape during high impact use. This has all too often resulted in a deformed bit getting stuck in the SDS chuck, with removal usually only possible by fully disassembling the drill. As a consequence, it is highly recommended that better quality (non-Silverline) SDS drill bits are procured alongside the Silverline drill especially if heavy masonry drilling is to be carried out.
Similarly, the carry case is also somewhat substandard with its handle, in particular, not fit for purpose, as it is too easily broken simply from carrying the case around with the heavy drill inside. One final point to note regarding the low-quality accessories involves the keyed drill chuck that comes with the drill. This is a relatively fragile component for a drill chuck, susceptible to breaking if used too forcefully. As a consequence, it is important to use personal protective equipment when drilling with this chuck and under no circumstances should it be used with the hammer-mode setting on.
From a safety standpoint, the Silverline drill includes a torque-limiting safety clutch but, as might be expected from an inexpensive drill, this should not be relied upon to fully protect the user in all situations. Instead, the Silverline drill should be used in an extra safety-conscious way taking into account the possibility of the drill spinning out of control should the drill bit become stuck.
One important aspect to note with the Silverline drill is to ensure sufficient application of grease has been made to the gearbox grease chamber (a pot of grease is included as part of the accompanying accessories). Adding grease to the gearbox should be done on first reception of the drill and repeatedly as the chamber empties, which usually occurs after a few hours of drill use. Failure to regularly top up the gearbox grease can lead to drill stoppages.
In addition, if the Silverline drill inexplicably stops during use, which it has been known to do, other things to also take into account include the thermal cut-out which may have been activated by the drill becoming too hot. Leaving the tool aside for an hour or so to let it cool down should reset the drill. In addition, the housing screws on the carbon brushes of the drill motor should also be checked to ensure they have not worked loose due to vibration, which can cause the carbon brushes to lose electrical contact with the motor.
Overall, the Silverline 633821 is a low-cost SDS hammer drill for the odd masonry drilling or demolition job a DIYer might encounter. The drill is not a premium product and that shows particularly with the accessories that come with the Silverline machine. The drill should not be considered a professional device and one has to be careful not to overload it. It is, however, a device that can almost be regarded as disposable, useful for a single medium-sized demolition job or a multitude of occasional DIY jobs around the home.
Click here for the official webpage of the Silverline 633821 hammer drill
Terratek 1500W SDS+
The Terratek 1500W is the main competitor to the powerful Wolf hammer drill. It has essentially the same high power of the Wolf but with only two thirds of its weight. It even incorporates a similar vibration dampener as the Wolf within its handle to reduce impact stress on the operator.
Like other drills in this category the Terratek corded hammer drill uses SDS plus drill bits. Unlike other competitors, the Terratek also includes a keyed chuck adaptor that can be slotted into the standard SDS chuck and allows you to use your traditional hammer drill bits - useful if you have been a long-time user of hammer drills and have built up your inventory of standard masonry bits.
As with other SDS hammer drills, the drill has a safety clutch to ensure that if the drill bit jams while being operated, the drill won't rotate violently out of control injuring the user. The Terratek hammer drill also features a reverse setting to deal with bit jams and similar situations, and as with many other of today's hammer drills, can also be used as an power chisel by disabling the rotary action while keeping the hammering function. Similarly, you also have the option of using the Terratek SDS drill as a regular drill by switching to the 'rotary only' setting but at an intrinsic weight of 4kg, it is best not to expect it to replace your 'everyday' drill.
Wolf 1500W SDS
The Wolf corded hammer drill is more about power than it is about refined drilling. Due to its heaviness and power, this is an SDS drill best used for heavier demolition work than it is for accurate masonry drilling. Like other powerful hammer drills, it has a slip clutch - an important safety feature for both the operator and the drill itself - to prevent the drill from spinning out of control if the drill bit jams. It also has a much needed rear dampener on the handle that reduces vibration stress on the user.
In addition to its hammer drill action (drill bit rotation and hammering), the Wolf SDS drill can also be used as a regular drill if need be by selecting the rotary-only function, and it can also act as a power chisel with hammer action only. However, as there is no drilling speed control, the machine can be a bit too powerful for some lighter drilling applications, and hole position accuracy can suffer.
Wolf-branded products are primarily sold by the UK Home Shopping network and tend to be good value products where you want a decent power tool that does the job but without the high price tag of brand-name tools. However, take note that this is a very heavy drill at 6 kg and is tiresome to hold for any length of time. In fact, it is the weight and power of the 1500W motor, that allows this beast of a drill to drill through almost anything with ease. One thing that is missing from the drill is a reverse setting which can be used to get out of situations where drill bits become jammed, but for the price at which this drill is available, you really can't expect it to do everything and then some!
