Bosch impact drills for DIYers

The impact drill is a handyman’s best friend in many different DIY projects. Check out the rest of this page for tips on how to get the most out of this universal tool.

For many DIYers, the impact drill is the best all-round tool among drills and screwdrivers . The tool can be used in a variety of ways, from standard impact drilling to percussion drilling, and is user-friendly thanks to its compact design.

Read below to find out what makes a good impact drill and how to select the best impact drill before purchasing.

Impact drills: what you need to know

What is an impact drill? If you’re searching for a bit of background information on these tools or how to use impact drill machines effectively, then keep reading to make an informed pre-purchase decision.

How does an impact drill work?

An impact drill - also known as an impact driver or combi drill - can be used for both drilling and screwing. In addition to the normal rotary motion that every drill has, a hammer, or “percussion” function can be switched on to provide impacting blows. Without this impact, you can bore holes into lighter materials (wood, metal, plastic, etc), but with the hammer action, harder materials - such as lightweight concrete or brick - can be penetrated.

This mechanism, which the cordless impact drill also has, is undoubtedly the special feature of these tools. It is produced by a mechanical percussion mechanism inside the machine, in which two sets of toothed gears, shaped like discs, "slide" over each other, causing the drill bit to move rapidly back and forth. The characteristic drilling noise is caused by these toothed gears.

This hammer action only acts over a few millimetres and is relatively weak. Therefore, a high number of impacts is necessary to achieve a drilling effect.

Because the two discs are separated by a spring, the hammer action only takes effect if you apply pressure to the impact drill from behind so that the gear teeth can engage. The harder you press, the stronger you drill.

Advantages and disadvantages of impact drills

The pros and cons of impact drills vary depending on the model and make. In general, however, the following benefits and hindrances apply to impact drills:

What can an impact drill be used for?

In practice, an impact drill is a versatile, well-rounded, multi-purpose tool. Typical impact drill uses include:

• Drilling holes in hard materials, like stone or lightweight concrete (as long as the percussion action is switched on). Since the impact is more refined than a rotary hammer, more precise drilling is possible.
• Drilling holes in softer materials, such as wood and metal. For this, the percussion mechanism must be switched off.

If required, you can also screw with impact drills that are equipped with variable speed control. However, a regular cordless drill can screw with far greater precision, so this is not the best use for an impact drill.

Technical features of a good impact drill

Some of the main factors that determine the efficiency of an impact drill include the power (measured in watts), the rotation speed, and the impact rate.

The impact rate is determined by the number of teeth on the gear discs and is typically between 30,000 and 50,000 blows per minute.

It’s great if an impact drill has an adjustable speed setting, but what’s even better is the Bosch Constant Speed mechanism. This electronic system automatically keeps the drill speed at a consistent pace, regardless of the drilling load. This means you always drill at the optimum speed for the material you are working on.

If you want to use an impact drill exclusively for drilling, your top priority should be the power. If you plan on using the machine primarily for screwing, you’ll need a model with a variable speed control. However, most drills do not come close to the precision and handiness of a good old screwdriver - especially for fine screwing.

In principle, corded tools are more powerful, but with a cordless drill you may access harder-to-reach spaces with ease. Like the wattage for corded tools, the voltage determines the power of cordless, or battery-powered, impact drills. The higher the voltage, the more powerful the tool.

Impact drills and safety

Percussion drills are very powerful. Therefore, as a DIYer, you should keep a few basic safety tips in mind when using them.

First off, you should think about what you want to use the electric impact drill for. This will determine whether you should work with or without the hammer action, the speed of the drill, and which impact drill bits  you should use. Other things to remember are as follows:

• Check for water pipes and power cables before drilling into walls. The safest way is to use an electric locator . Read more about locating cables  on the Bosch website.
• Wear the appropriate protective equipment, such as goggles. With impact drills, you’ll also need effective hearing protection when using the hammer function.
• Make sure you have a safe and secure standing area with sure footing, especially if you have to apply a lot of pressure.
• Use safety features such as the Bosch Kickback Control, which turns the machine off automatically if the drill attachment gets jammed. This prevents the impact drill from rotating on its own axis and significantly reduces the risk of injury.

Impact drills: frequently asked questions

Before you buy an impact drill, you’ll no doubt have a few questions. Which type of impact drill is best? There is the question of using an impact drill vs a hammer drill, but there’s also a regular drill vs impact drill dilemma!

Below we’ve listed some FAQs for you to help you decide which is the best impact drill to buy. You can also find more information on impact drill bits and which impact drill set is most effective.

When do you need an impact drill?

Simply put, an impact drill is needed when a normal, rotation-only drill is no longer sufficient. For instance, when drilling holes in harder materials such as brick or soft concrete.

Since you can use an impact drill to create precise holes in soft and hard materials, this power tool is fundamental to every home workshop.

What is the difference between an impact drill and a rotary hammer drill?

The two tools are sometimes confused with each other, but they are fundamentally different in the way they work.

It is true that both have a power-boosting hammer function. However, the main difference between impact drill and hammer drill machines is that an impact drill’s blows are frequent, yet weak, whereas the pneumatic percussion mechanism of the hammer drill produces fewer, but much stronger blows.

Unlike with an impact drill, the rotary hammer drill does not require the user to apply manual pressure. Working with a rotary hammer is therefore less tiring, which is why the hammer drill is suitable for particularly hard materials, like reinforced concrete. It can drill and chisel, but for precise holes in softer materials, an impact drill is the ideal choice.

You can find more information on the differences between impact drills and hammer drills on our website. There are tutorial videos, articles, and guides to provide you with all the details you need to make a well-informed choice of which electric or cordless impact drill to buy.

Why does the impact drill hammer action require pressure to work?

The hammer action mechanism works by pushing two disc gears with opposingly-shaped teeth together using the force of a spring. This requires manual effort from the user to operate. The harder the material you’re drilling into, the more force you’ll need to use.

How many watts should an impact drill have?

That depends mainly on what you want to use it for. Put simply, the higher the power, the better the performance. However, so much power is often unnecessary. If you use your impact drill a lot and for longer periods, you should make sure that the electrical power is sufficient.

For corded tools, the power depends on the wattage. As a rule of thumb, devices with 400-500 watts or more provide enough power for the average DIYer. For cordless impact drills, the power is determined by the voltage. Modern 12-volt impact drills are sufficient for all-round DIY projects at home, but more powerful 18-volt models are also available.

What materials is an impact drill not suitable for?

In theory, impact drills are universal tools that can be used for drilling and screwing into almost any material. However, for particularly hard and heavy materials (like reinforced concrete), you should use a rotary hammer  drill.

What DIY projects can I use my impact drill for?

An impact drill can be used whenever there is something that needs drilling or screwing (except really hard materials). You can switch on the hammer action or keep it off, depending on the type of wall you’re drilling.

Caution: When using an impact drill, take care to avoid using the hammer function when it’s not needed! For instance, drilling holes in bathroom tiles does not require the impact function - the hammer action will cause the tiles to break. The same applies when drilling into softer materials.

There are so many DIY projects  you can get inspired by! Start simple and learn how to mount floating shelves  to a wall. Once you’ve caught the DIY fever you can move onto larger projects. Have you always wanted to build your own furniture ? Fancy a go at making a TV stand or a DIY desk for your home office ? Whatever your DIY plans are, we hope you enjoy using your Bosch impact drill!