Just about every homeowner at some point has had to drill holes or screw something or other around the house, so it is not surprising that some of the first power tools that most people invest in are the humble hand drill and power screwdriver. These days, however, power drills and electric screwdrivers have become quite complicated devices that come in a range of different categories and sizes, each designed for specific types of drilling and screw driving. This can make choosing the right drill, electric screwdriver, or hybrid of the two, the drill driver, quite a challenge.
In this review, we have focused on the combination (combi) drill or combi drill driver as it is usually one of the first drills that DIYers and homeowners get their hands on. We first look at the different types of drills and drill drivers available and how combi drills fit in alongside these other drill and electric screwdriver types. We then look at the features that generally come on a combi drill and the specifications to watch out for when purchasing this power tool type. Once we have a good idea of what characteristics are best for the ideal combi drill, we then examine the range of combi drills that are currently popular with UK DIYers and tradespersons towards the end of this page.
The Hand Drill, the Screwdriver, and the Drill Driver
The hand drill and screwdriver has been around for centuries, first as manually-operated devices, and then as tools became electrified in the 1900’s, we got the beginnings of the modern power drill and power screwdriver. Today, many households in the UK own at least one drill, an electric screwdriver, or drill driver, while DIYers tend to have a range of different drilling and power screw driving tools to tackle an array of different of jobs that one encounters doing DIY work. Most drills, electric screwdrivers, and drill drivers can be split up into the following categories:
The Electric Screwdriver: As its name clearly indicates, the electric screwdriver is only designed for screwing and unscrewing fasteners. It often looks similar to a drill but usually does not possess the rotational force or torque necessary to act as a drill, nor does it have a chuck that is able to hold regular drill bits.
The Drill Driver: The drill driver is a multi-functional power tool which will usually be able to drill holes in a range of materials including wood, metal, plastic and others. It tends to be less heavy duty than the equivalent combi drill (see below) and when used with the right drill driver bits, it can also act as an electric screwdriver.
The Combination (Combi) Drill or Combi Drill Driver: The combi drill or combi drill driver is very much like the drill driver described above, able to drill holes in softer materials like wood as well as screw and unscrew fasteners. However, unlike the plain drill driver, the combi drill also has the ability to drill into harder masonry-type materials such as concrete or brick. This is accomplished by the switching on of an inline hammering mechanism on the tool. This generates a percussive forward force at the same time as the drill bit is being rotated, efficiently driving the drill bit through these harder materials. Combi drills are not always referred to as combi drills but sometimes simply described as ‘drills with hammer function’ or something similar.
The Hammer Drill: The hammer drill uses the same linear hammering mechanism as the combi drill in order to effectively cut into masonry but it tends to be a drill that is more specialised for hammer drilling than the combi drill and is not designed for screw driving.
The SDS Hammer Drill: The SDS hammer drill or rotary hammer is similar to the regular hammer drill but uses a special SDS chuck system to more effectively cut through masonry than standard hammer drills. It is usually not designed to accommodate other types of drill bits so is only used for hammer drilling. For more detailed information on this type of drill, see our review page on SDS hammer drills.
The Impact Driver: The impact driver is another type of drill driver that is able to bring to bear large amounts of torque which is particularly useful for unscrewing stubborn fasteners as well as driving home large screws into harder materials efficiently. It does this by using a rotational hammering mechanism distinct from the inline linear hammering mechanism found in combi drills and hammer drills. For more detailed information, see our review page on impact drivers.
What to look for in a Combi Drill
The most popular combi drills tend to be battery-operated so the power rating for these machines is measured in volts. In general, the higher the voltage at which the combi drill operates, the higher the maximum torque it can exert and the tougher the drilling it can perform. However, at the same time, the higher the voltage of the combi drill, the heavier and more bulky it is likely to be. The majority of today’s battery-operated combi drills are designed to operate from an 18V battery which usually provides sufficient power for all the typical DIY jobs one encounters.
As alluded to above, the maximum torque that combi drills can generate is partially correlated with the power level of the tool, however, it is not all power level-dependent, as different designs and component quality also determine the maximum torque a combi drill will ultimately be able to exert. In general, the higher the maximum torque the machine can generate, the larger the drill bits the combi drill can use and the larger the hole diameters it can produce. As a consequence, this is one metric to keep a close eye on when purchasing your next combi drill. Of course, the torque levels on a combi drill are usually nowhere as high as those found on impact drivers which are specifically designed to have very high torque levels in order to deal with stubborn fasteners.
Maximum Drilling Diameters
As mentioned above, the maximum torque levels a combi drill can produce determines the maximum size of the drill bit it can operate effectively and the maximum hole diameter size the drill can produce. Obviously one wants to go for the combi drill that can produce the largest range of hole diameters that one can afford so as to have the most versatile combi drill at one’s disposal.
The speed at which the spindle turns in a combi drill is sometimes referred to as its no-load speed and is given in revolutions-per-minute (rpm). When drilling different materials, there is usually an ideal speed range at which that material is most effectively drilled. For masonry drilling for example, slower rotational speeds produce better results and reduce the chance that the drill bit overheats, while when drilling into materials like wood, the higher rotational speeds usually produce better results. As a consequence, combi drills often have a way of regulating their maximum speeds, usually providing at least two speed levels at which they can be operated at.
Blows Per Minute
The blows per minute (bpm) metric on a combi drill refers to the speed at which the inline hammering mechanism of the drill operates. In theory, a higher bpm will apply the impact force of the drill more quickly and should result in faster drilling through masonry. In practice however, most combi drill hammering speeds are so high that any differences in the rates of masonry drilling between machines with different bpm specifications are likely to be mostly unnoticeable.
A combi drill tends to be one of the power tools that is most often used by both DIYers and tradespeople, so the weight of the tool is an important consideration when looking to purchase one as heavier machines will tire operators out more quickly than lighter ones. In addition, the heavier the combi drill, the more unwieldy the machine is. In battery-operated combi drills, weight is not solely determined by the drill body but also by the size of battery that is installed. Many combi drills these days are compatible with a range of different capacity batteries produced by the drill manufacturer, many of which are designed to be exchangeable between different power tools from the same range. As a consequence, the overall weight of the combi drills can vary depending on the capacity of the battery used.
Power tools almost always benefit from having their own carry case to protect them from accidental damage when not being used or when being transported. Therefore getting a combi drill that comes with its own carry case or bag is highly recommended.
Combi drills are not quiet machines especially when operating in hammer mode during masonry drilling. However combi drills are not as noisy as impact drivers which tend to be one of the noisiest drill types available.
Popular Combi Drills in the UK