If you are looking for an efficient tool for your DIY home building kit, to finish projects or for use on your construction site when you’re working with several types of materials such as stone, wood or brick, then using a hammer drill allows you to finish your work more quickly and efficiently as compared to a regular hammer.
Also known as a hammering drill or a roto-drill, the hammer drill is a rotary drill machine that also has a hammering action, which provides quick and short hammer thrusts to crush brittle material and it allows you to drill faster with much lesser effort.
Hammer drills are especially beneficial when you want to drill holes in brick walls and concrete foundations and the hammer drill combines the advantages of both the drill, as well as the hammer. Hammer drills are usually powered by electricity and these days, you have battery-powered, cordless options too.
Sometimes drills cannot penetrate some kinds of materials and this may be due to various factors such as:
You may not be using the correct type of drill for the particular surface or material. For instance, a regular drill can drill holes only in materials such as wood, plastics or metal, whereas for tougher materials like brick, stone, hardwood or concrete, you may have to use a hammer drill.
So, choosing the right tool plays a very important role in being able to drill holes through materials.
The other important factor that plays a very important role in being able to drill holes into materials is the bits used in the drill. For example, normal bits cannot drill holes through hard materials like stone, concrete, masonry, etc.
For this, you will have to use bits with SDS or carbide tips that can penetrate the tough surface. Also, you must ensure that the drill bit that you use is sharp and not dull, as dull bits will not be able to penetrate the materials easily.
A hammer drill is essentially an electric drill which revolves and also provides a hammer-like action while providing more force via the rotary action. Due to the powerful performance of the rotating motion, the hammer drill delivers hard and fast blows and is capable of demolishing tough materials like brick, stone and wood.
A regular drill is quite basic in its operation and just spins. A regular drill is useful for drilling into most kinds of materials such as plastic, wood and metals. A hammer drill hammers and spins as well, i.e., along with spinning around, the drill bit also hammers into the material that you are drilling.
A hammer drill produces short, fast and successive blows that increase the force significantly and allows you to drill into extremely hard materials such as concrete and masonry very easily.
In a hammer drill, the bit’s hammering action breaks the concrete and makes the bit to drive into the hard material very easily. However, most hammer drills can be used as regular drills too and are equipped with a feature that must be switched on for the hammering action.
The difference between a hammer drill and an impact drill is essentially in the difference in their appearance, purpose, weight and method of operation.
A hammer drill is mainly used for drilling into hard surfaces such as concrete, brick, etc. and some hammer drills also offer the option of being used as a regular drill. On the other hand, the impact drill is mainly used for driving screws, nuts, nails, etc. and it can also be used for the purpose of drilling.
In terms of the appearance, both the hammer drill and the impact drill are very different. The impact drill is shorter and stouter and instead of a chuck, it has a hexagonal socket. The impact drill may have an adapter where you can attach bits. The hammer drill, on the other hand, is large and heavy and it has a drill chuck that can accommodate various sizes and types of bits.
When you speak about the operation, the hammer drill applies more pressure when compared to the impact drill. When being used, the hammer drill feels like as if you’re hitting with a hammer very fast and it is also quite loud. The hammer drill vibrates back and forth and has an adjustable clutch to adjust the force that is being applied.
The impact drill has a rotary motion and works like a cordless screwdriver but it has a special mechanism that provides a greater force. An impact driver does not have an adjustable clutch and you cannot reduce the force.
A hammer drill is more expensive when compared to an impact drill and a hammer drill can be used for drilling jobs that are tougher. Impact drills are smaller, lightweight and have more features and they are more practical for homeowners and small projects.
A hammer drill is mainly used to drill holes into concrete, drywall and backer boards, while an impact driver is used to drive long and big screws into very hard materials such as drywall, masonry and concrete, as impact drivers are more powerful when compared to regular drill/drivers.
The main difference between hammer drills and impact drivers are the type of bits they accommodate. While the three-jaw chuck of hammer drills can accommodate both hex and round bits, the impact driver is equipped with a locking collet which only accommodates hex-shank bits.
When it comes down to the action of a hammer drill and impact driver, the spinning action is compounded by the hammering action in the hammer drill. The force applied is just like a hammer along the drill bit axis and while spinning, it also is accompanied by the pounding, while the impact driver only has a rotational movement.
With the impact driver, you have a bigger torque that is put on the head of the screw, which is why you can use impact drivers to put long screws into tough and heavy-duty materials quickly and easily without the heads of the screws getting stripped. Also, the impact driver does not have a bulky clutch and is more compact, lightweight and easy to handle in constricted spaces.
In addition, the torque of the impact driver is rotational, which means that the force is not transferred to your hand and wrist like in a hammer drill that can be quite tiring to use for long periods of time.
In terms of the pounding or hammering force, both hammer drills, as well as rotary hammers or rotary hammer drills, produce the same action that makes them extremely powerful tools to drill through tough masonry.
A hammer drill comprises two discs (or ratchets) which have ridges. As one of the discs slides against the other, it causes the chuck to pound forwards and backward and if there is no force applied on the chuck, the clutch separates the 2 discs and the hammering action stops.
The rotary hammer, on the other hand, creates the hammering action with a piston which is driven by a crankshaft. The piston moves inside a cylinder, which when driven forwards creates an air pressure, which in turn drives the hammer mechanism.
The impact energy provided by rotary hammer drills is much more than hammer drills. Rotary hammer drills make use of a tungsten carbide drill bit and also have an SDS shank.
Rotary hammer drills are more durable when compared to hammer drills and are usually preferred by professionals. Also, rotary hammer drills have 3 settings i.e. the drill mode, the hammer mode or the hammer drill mode.
The hammer drill features a clutch which allows it to punch the head inside and outside continually, while at the same time, the drill bit spins. The bit moves forward with the in/out motion causing rapid and tiny blows.
When you activate the hammer mode, the drill starts to rotate and also a creates a forward vibrating motion, which causes the drill bit to start pushing into the material. The hammering action of the hammer drill produces fast and clean penetration into the material.
If you want to make holes, then using a standard drill is sufficient; however, with a hammer drill, the time taken and the effort is much lesser.
The speed of the hammer drill is affected by 2 factors. The RPM or the rotations or revolutions that the hammer drill can perform in a minute, which is affected by the pulling the trigger and the amount of pressure that is applied with the drill on the particular surface. The RPM essentially indicates how fast the hammer drill is.
When the pressure is greater, the hammering action is also more and the simultaneous rotating and hammering action lets you drill into surfaces like concrete, masonry, etc. For medium-duty drilling jobs, a drill with 1,200-1,500 RPM is ideal and any speed over 2,000 RPM is suitable for heavy-duty drilling jobs.
The bit of the hammer drill not only spins but also punches in and out along the bit’s axis administering small and quick blows. The hammering action or the number of blows the hammer drill makes in a minute is measured in terms of blows per minute or BPM or impacts per minute or IPM. The greater the BPM, the stronger will be the hammering action of the drill.
The blows of the drill are quite low in terms of the force; however, at the rate of 20,000-50,000 BPM (blows per minute), which is around 3-4 times faster compared to a standard electric drill, are sufficient to drill through concrete or brick effectively.
This rapid hammering action combined with the spinning motion sets the hammer drill apart from a regular drill offering powerful performance in a very short time.
Let's take a look on some of the most popular hammer drill types:
Hammer drills usually work using the percussion hammering or the cam-action mechanism, where 2 sets of gears with teeth interact with one another mechanically to produce the hammering action while the drill bit also rotates.
A percussion drill is similar to the rotary hammer drill. However, the difference between the two is that in a percussion drill, you cannot use the hammering action without the rotational function, as the rotation of the chuck initiates the hammering action of the drill.
Percussion drills are suitable for DIY drilling tasks, although they are much slower than rotary drills. Percussion drills can also be used for drilling semi-hard materials like light concrete, limestone, etc.
Some advanced high-end percussion drill models can be used on harder materials such as masonry or concrete, although they can cause strong vibrations and a loud noise while drilling.
More advanced drills that are larger, deliver larger force of impact by making use of electro-pneumatic hammering technology. It is powered by electric current and does not use of an air compressor. Electro-pneumatic drills make use of a system which comprises the drive piston, as well as the flying piston.
The drive piston moves backward and forwards within a cylinder by means of an electric motor which turns the crank. The same cylinder contains the flying piston on the other side. Both the pistons don’t touch each other; however, the air pressure within the electro-pneumatic cylinder allows an efficient transfer hammering energy compared to the springs in the cam-action tools.
Most rotary hammers or jackhammers make use of the EP technology. In the modern models, you can make use of the rotation and hammer modes separately or together.
When the work you need to do is heavy-duty and one that a standard drill cannot handle, then a hammer drill becomes very useful. In the drill hammer, you can make use of the switch and change the standard rotation mode into a spinning-cum-hammer mode.
Hammer drills are usually used by contractors and professionals for heavy-duty and large-scale projects to drill into tough materials. A hammer drill is the first choice of tools for electrical box installations or any other kind of drilling jobs on block or brick walls.
Hammer drills are not only used by professionals alone, they are extremely handy for DIYers and homeowners too and can be used for jobs such as installing cabinets and shelves on hard surfaces, etc.
The high speed produced by hammer drills make them suitable for using these tools for several off-the-chart tasks. When using the hammer drill in the rotary mode, it can be used for jobs such as polishing pads, sanding drums, wire brushes, etc.
When used in the rotary mode, the hammer drill can be used to make holes with large-sized hole saws. The heavy and sturdy build of the hammer drill allows you to control the tool much better when making big holes.
Normal drill bits are usually used to drill through plastic, wood and metals. However, hammer drills are used to drill through harder materials like concrete, where normal bits will not be effective. The drill bits for concrete are a bit different.
They have superior carbide tips, are heat-treated or hardened and they have a slightly different design on the head when compared to regular bits, which helps to reduce the breakage in the case of heavy use.
The hammer drill bits are in the shape of a hammer. Hammer drill bits are also available in different sizes, 3/16 and 5/32, which are the most common sizes of bits used to drill through concrete.
Here are some of the most important drilling tips:
However carefully you drill using the hammer drill, there is always a chance of over drilling and wasting a good piece of wood. So, when you are using the hammer drill, it is always a good idea to make use of backup methods to prevent over drilling.
Here are some tips on how you can achieve the exact depth required for the particular job without actually over drilling and these techniques can help you drill smoothly and get more accurate results.
Most hammer drills today are sold along with a depth stop and side handle, which can help you to avoid over drilling. You can save your time, as well as your bits by not drilling the holes deeper than necessary.
Also, avoid drilling through the concrete block to the core. Some of the plastic anchors require a back to stop them, otherwise, they will get completely pushed through the hole.
Using masking tape, make a flag on the bit by leaving some length of tape on both ends and then stick them together. Do not wrap the masking tape around the bit, as the sleeve will move or slide up. When the flag around the bit starts sweeping the sawdust away, then you will know that you have completed the drilling.
Adjust your bit in the chuck of the drill in such a way that the bit measures slightly more than the screw’s length. This is an excellent method, as the chuck will not allow you to over drill; however, you must ensure that the chuck does not touch the wood or the wood will get damaged.
Some of the other things you should not do with the hammer drill are:
When the correct RPM is combined with the right pressure, at certain spots, you can drill with the hammer drill the fastest. However, you cannot find this spot simply by pushing very hard. Too much pressure causes excess wear on the motor gears and may cause the bits to break and also slow down the entire drilling process.
If you require drilling holes which are more than the capacity of your hammer drill, then begin by drilling the smaller hole first. This will help to reduce the hammer drill’s load. Also, the smaller-sized bits do not slip around like the larger bits and this can help when you require the hole in a specific spot.
The drill bits of the hammer drill have flutes which are designed in such a way so as to drag the debris from the hole while you drill. However, it is a good idea to clear the hole by pulling the bit out from the hole occasionally while you are drilling.
Removing the debris from the hole helps to reduce friction, which helps to make the process of drilling much smoother and this also helps to extend the life of the drill bits.
The work environment where a hammer drill is used is quite a tough one and to keep your hammer drill in an efficient working condition, here are some maintenance tips:
Not only suitable for home and DIY projects, a hammer drill is an extremely versatile and an indispensable tool for industrial, commercial applications too.
Hammer drills are extremely powerful tools and as a buyer, you must evaluate and choose the one that is right for the job you intend to use it for. There are many different types of hammer drills and you need to decide on the one that will be the best for your projects.
Our detailed buying guide will be able to help you make the choice of the best hammer drill for you by listing out the various factors that you should consider and what you should look for in a hammer drill before buying the tool.
The buying guide also has a detailed review of the best hammer drills in the market, so that you can evaluate the various options available before making your final decision.