Impact Wrenches

The impact wrench combines power and portability for quick and easy fastening. They're designed to provide high-impact, high-torque usability no matter the situation or location, aided by a light and ergonomic design for effortless all-day usage.
Cromwell stocks a wide range of impact wrenches, from trusted brands such as Bosch®, Makita®, Chicago Pneumatic®, DeWalt® and many more.

What are impact wrenches?

Impact wrenches look and function much like a traditional cordless drill, however they are a lot stronger, thanks to far greater rotational torque. Additionally, they're primarily designed for use on nuts and bolts rather than screws.

The ultimate benefit of the impact wrench is how much extra working force is achieved over a standard drill. This is thanks to a spring, hammer and anvil mechanism that 'hits' the bolt or fastener, providing a powerful jolt to effectively drive it in (or out). Most impact wrenches hit at well over 60 times a second, creating an enormous amount of usable force for a tool of this size.

A good way to differentiate impact wrenches from regular drills is this; a normal drill simply pushes the bolt, putting excess strain on the fastener that often results in warping or stripping. An impact wrench rapidly 'punches' the bolt, delivering a much greater downward force with far less damage to the bolt and the screw it's on.

Why an impact wrench?

Impact wrenches make inserting and removing bolts and fasteners exceptionally safe, simple, and speedy. With the correct attachments, they can even drill holes in a pinch. Compared to other tools of its type - such as combi drills and drill drivers - the impact wrench is known for producing far greater torque. This makes them particularly suitable for work on tough materials, and driving large, stubborn bolts without causing excess damage or wear.

Often described as 'the ultimate fastening tool', impact wrenches utilise a square drive to grip any socket without hassle. Impact wrenches make use of their incredibly high torque to remove the stress from the operator and minimise the risk of stripping or damaging bolts and screws. As such, they provide the most efficient way to drive a fastener in or out.

When are impact wrenches used?

• Automotive Industry - Impact wrenches are held in high regard by those who work in the automotive industry. They can remove stubborn wheel and lug nuts effortlessly, and are highly suited to a wide range of other automotive tasks that also makes them invaluable for mechanical engineering works.

• Removing Fasteners - What makes impact wrenches excellent at fastening also makes them highly effective at unfastening. Impact wrenches are often used for removing tight, stubborn bolts and fasteners without causing damage.

• Drilling - Impact wrenches are similar to impact drivers in that, as the name suggests, they're designed for driving over drilling. Yet if you have the correct drill bit, impact wrenches make capable drills. You won't want to throw out your dedicated drill anytime soon - the hammering motion of an impact wrench doesn't result in smooth drilling.

If you're looking for the ideal tool for your job, feel free to ask our experts for specialised advice.

Types of impact wrench

Impact wrenches are one thing, but when you've also got hammer drills, impact drivers and air wrenches to contend with, it can be hard to know which tool is the right choice. Let's clear up some of the confusion:

• Impact Wrench - Uses a square drive that a socket can be attached to. Utilises a hammering motion to quickly drive bolts or fasteners. Designed for use when working with hex-head fasteners, such as heavy-duty nuts and bolts.

• Impact Driver - Functionally very similar to the impact wrench but utilises a ¼ inch hex collet for smaller bits. Designed for use when working with screws and fasteners that require a drill bit to effectively tighten or remove.

• Hammer Drill - Similar in design to an impact driver, but different in how force is delivered. Impact drivers increase the force perpendicular to the bit, whereas hammer drills deliver their force directly through the bit - more akin to how a jackhammer works. Designed for heavy-duty drilling, rather than driving.

• Air Wrench - Similar to a standard impact wrench but powered by compressed air. Typically suited to stationary work due to the inconvenience of a bulky air compressor.

Considerations when choosing an impact wrench

• Voltage - Impact wrenches come with a range of available power ratings, the prominent two being 12V and 18V. Voltage affects torque, meaning 18V drivers are more powerful - however this comes at a slight increase in both cost and bulk.

• Corded vs. Cordless - This essentially comes down to weight vs. practicality. Cordless impact wrenches can be bulkier thanks to heavy battery packs, but are much easier to manoeuvre and transport thanks to a lack of wires.

• Handling and Control - 18V models are of course more powerful, yet 12V models are smaller and lighter - allowing for easier access for work in awkward places.

Impact wrench jargon buster

• Brushless Motor - Nowadays, many impact wrenches have brushless motors. Brushless motors provide greater energy efficiency, resulting in increased runtime per charge and consistent power delivery no matter the battery level. The downside is that they are more expensive to design and implement, so it may be hard to get a brushless model on a tight budget.

• Impact Rated Accessories - Standard wrench and drill bits are often not designed to withstand the stress placed on them by an impact wrench.
When buying attachments, always ensure they are 'impact rated' for peace of mind. They usually come in a darker grey or black finish to signify their extra strength.

Oil Pulse Mechanisms

Most impact wrenches are noisy. Many newer models utilise impact mechanisms with hydraulic fluid to reduce noise, although most professionals still opt to use ear protection.


Can you use an impact wrench to remove screws?

With certain attachments, Impact wrenches can help remove screws, as well as drive them. An impact driver would be more suitable for removing screws, however.

Will impact wrench drill into concrete?

No - impact wrenches are designed for use with nuts and bolts. Their hammering motion is likely to break concrete.
For drilling concrete, the correct tool is typically a rotary hammer.

Will an impact wrench remove wheel nuts?

Yes, the impact wrench excels at wheel and lug nut fastening or removal.