Types of Impact Wrench – Choose the best one for you

Power tools are the modern saviors of mechanics and construction workers.

Just as their name implies, they do come with a lot of power. They also come in various sizes and with a wide range of applications across different jobs.

What is an Impact Wrench?

 Power tools have made the lives of a lot of DIY (do it yourself) savvy individuals easy. One of the most common power tools found in homes and in workshops is the impact wrench.

An impact wrench is a power tool that is used to tighten or loosen nuts, fasteners, or large bolts with minimal effort from the operator.

The impact wrench, also known as an impact gun or torque gun, works by storing kinetic energy in a rotating mass and then delivering a high output torque in a series of short concussive blows through an output shaft.

Impact wrenches are frequently used in the manufacture and repair of automobiles, building and construction projects, as well as in a variety of other industries.

Types of Impact Wrench (Power Source)

There are three basic types of impact wrenches classified according to their power source and we will be examining each of them one by one.

Pneumatic (Air-Operated)

This type of impact wrenches makes use of compressed air and a compressor which supplies the power required to work.

They have a simple design with fewer moving parts and are capable of producing high amounts of torque required for heavy-duty jobs.

Electric Operated

The electric-operated impact wrenches come in two forms. We have the corded and the cordless.

Corded Impact Wrench

The corded Impact Wrench requires an electric supply to operate. They have an electric motor attached to the rear end of the tool which is responsible for driving the hammer unit that in turn delivers its energy to the output shaft.

Cordless Impact Wrench

The cordless impact wrench is battery-powered. The wrench makes use of several types of rechargeable batteries (NiCad, NiMH, Li-Ion) to store charge which is used for operations later on.

The major advantage the cordless wrench has is that it is portable and can easily be used in situations where there is no electric supply.

We have a detailed discussion on Corded vs Cordless Power Tools. It will help you to choose the right product for your purpose.

Hydraulic Operated

The Hydraulic impact wrenches generate rotational force by utilizing hydraulic fluid and a hydraulic motor.

Electric vs Pneumatic Impact Wrench

Before we decide on which Impact wrench is better, let’s take a quick look at both wrenches in terms of their features, pros, and cons.

Pneumatic impact wrench

Compressed air supplied by a compressor propels the pneumatic impact wrenches. They have a simple design with two openings on opposite ends to allow air to pass through. This design enables them to generate extremely high torque with minimal speed control.

Pneumatic impact wrenches are extremely powerful tools that can generate large amounts of torque depending on the size of the compressor attached to them.

The disadvantage of using this type of wrench is that it has less mobility due to its compressor requirement, which also determines the amount of torque generated.

On the Upside, their simplistic design prevents overheating because of the absence of moving parts within the wrench which also makes it very affordable.

Electric Impact wrench

On the other hand, the electric impact wrenches work with either a power source or a battery for the corded and cordless models. The cordless types have a complex design which allows for good speed controls while working.

The advantage of using this type of wrench over their pneumatic counterparts is that they are highly portable and can be used in various critical and tight situations.

The downside is that they are more expensive, and their moving parts allow for the possibility of overheating when used for very long periods.


Because of their operating principles and somewhat dissimilar features, both Pneumatic and Electric Impact wrenches have their advantages and disadvantages, and as a result, they have various fields of use.

The pneumatic impact wrench is better suited for heavy-duty jobs, manufacturing assembly lines, and auto repair shops where a lot of torque is needed to get the job done. While their electric counterparts are better suited for indoor home jobs, construction, and routine tire changes,

The job for which the Impact wrench is being compared has a big role in determining which one is superior.

Other Classifications of Impact Wrench

Right Angle Impact Wrench

The name of this wrench comes from the anvil’s angle of inclination. The anvil, as the name implies, is inclined at a 90-degree angle to the wrench’s body.

This makes it convenient and appropriate for getting into tight spaces where a standard cordless wrench may not fit perfectly. The Milwaukee M12 Fuel 3/8 inch impact wrench is an example of this type of wrench.

Butterfly Impact Wrench

The Butterfly Impact Wrench has a lightweight composite housing and a Jumbo clutch capable of generating up to 95ft. lb of torque. Its throttle design enables quick and easy directional changes in confined spaces.

This type of wrench is most suitable for working on motorized vehicles like lawnmowers or tight areas where a compact impact wrench is required. They can also be cordless or pneumatic depending on their purpose.

Ratchet Impact Wrench

This sort of wrench was created with a higher speed and lower torque in mind. The wrench’s design eliminates the tension of using a manual ratchet when working on your car or at home.

The wrench’s motor is powered by a battery, which rotates the ratchet head.

Sizes of Impact Wrench Socket

Impact wrenches sockets come in various metric and standard bolt sizes.

Metric sockets begin at 4 mm and progress in 2 mm increments up to 14 mm. Standard sockets start at 3/16-inch and progress in 1/16-inch increments up to 9/16-inch.

Let’s take a quick look at some of the more common socket sizes and their functions.

¼ inch

This is the smallest size of impact wrench available. This type of wrench is useful for working in tight spaces and small corners where big wrenches won’t be able to maneuver easily.

The typical quarter-inch impact wrench is designed for more precision and less torque and so they are useful for working on equipment such as lawnmowers where precision is required to change the blades of the manual lawnmower.

3/8 inch

The next size after the ¼ impact wrench socket is the 3/8 inch. Just like the ¼ inch sockets, they are also useful for working in tight spaces and home projects.

The basic difference between the two apart from the size is that the 3/8 inch has more torque available to it and so can be used for removing and fastening bolts and nuts from small automobile vehicles.

 ½ inch

The ½ inch impact wrench socket is the most common size in the family. Because of its ability to blend torque, compatibility, and speed in one instrument, this size of impact wrench is highly versatile.

When it comes to changing car tires and basic construction or home repair projects, the ½ inch Impact wrench is your go-to tool.

¾ inch

This size of impact wrench comes in just after the ½ inch size. The application of this size of an impact wrench can be found in the Automobile assembly lines or in construction sites where its available torque can be put to good use.

They are also quite useful when it comes to working on big trucks where the sizes of the bolts and nuts are quite large and require a little bit of extra force before they give way.

1 inch

This is one of the largest impact wrenches available. When mechanics say “it’s time to bring in the big guns”, they’re most likely referring to impact wrench sockets of this size.

 Impact wrenches of this size are commonly seen in heavy-duty assembly lines when a large amount of torque is required to release or tighten a bolt or nut.

Hog Ring Anvil and Detent Pin Anvil

Impact wrenches have a safety feature that prevents the socket from suddenly falling while working. This safety feature can take the form of a hog ring or a detent pin.

The hog ring, also known as a friction ring, grips the inside of a socket to which it is connected. It creates friction between the socket and the anvil, making it difficult for the socket to slip out while in use.

The ring begins to wear out over time, and the level of friction between the socket and anvil decreases. To avoid workplace accidents, the hog ring should be changed on a regular basis.

The detent pin is a spring-loaded pin that keeps the socket firmly attached to the anvil. Before the socket can be removed from the impact wrench, a retention pin on the Detent pin anvil must be pressed in.

Depending on how frequently the socket is used, the detent pin can be aligned with the socket or used without alignment.

Sockets can be easily changed after use with little effort if they are not aligned; however, if the socket and the pin are aligned, you may have to exert more effort before switching sockets.

Both the detent pin and the hog ring serve the same purpose: they keep the socket attached to the driver while it is in use.

What to Look for Before Buying an Impact Wrench

Generally, before you go into the market to pick a product, it is usually advisable to do your due diligence especially when there are varieties of that product available.

The same goes for an impact wrench, before you buy an impact wrench there are a lot of factors to consider, while some are more important than the other, each of the factors has a role to play when it comes to eventually selecting the best option for your designated use.

Below are some of the factors to look out for before selecting an impact wrench:

Types of Motor

There are two major types of motors employed in the fabrication of Impact wrenches. They are the brushless and the brushed motors.

Both of them have the same working principle with the basic difference being that the brushless types use magnets to convert the current into mechanical energy while the brushed type makes use of carbon brushes and slip rings.

In terms of effectiveness, the brushless motors are more efficient, powerful and last longer, the only downside they have to their brushed counterparts is that they are more expensive because of their complex mechanism of operation.


The importance of torque when it comes to impact wrenches cannot be over-emphasized. The torque is the force responsible for performing the work that the impact wrench does on the bolt.

Each job application has a required amount of torque needed to perform the job effectively. A small 3/8 impact wrench will have a considerably smaller torque than a 3/4 impact wrench. This is mainly because they have different applications and hence require different amounts of force.

While the ¾ impact wrench is used in automobile industries, construction sites, and for working on large trucks that require a great amount of force, the 3/8 wrench is more suited for simple home uses and for changing the tires of vehicles.

Another important term to consider when it comes to torque is called Nut Busting torque or breakaway torque. This refers to the initial amount of force the tool applies to breakaway the nut before it continues with its normal operation.

Impact wrenches typically have a Nut Bursting torque value that is way higher than their torque specification. For example, a wrench rated 1000Nm of torque can have a Nut busting torque of 1600Nm.


The RPM of an impact wrench refers to the speed of the Impact wrench.

Nowadays a lot of cordless impact wrenches come with variable speed options to enable the user to maintain control of the speed required for a particular job.

Safety Fractures

When using power tools there are certain safety guidelines to follow to avoid workplace accidents. If you are an armature with power tools, a good rule would be to ensure the area is clear so as not to trip.

It would also be to your advantage to read the manual that came with the tool before you use it.


Initially impact wrenches used a Nickel-cadmium battery commonly known as NiCad. later on, the Nicad batteries were improved leading to the development of NiMH batteries which last longer than their NiCad counterpart.

However, Nowadays with the advancement in battery technologies, most impact wrenches come with Li-ION batteries which are more durable and last longer.

The cordless impact wrenches are powered by a battery that powers the motor. When selecting an impact wrench, it is critical to consider the wrench’s battery specifications.

It is also worth noting that some impact wrenches come with two batteries, so do your homework before purchasing a cordless impact wrench.

LED Light

Some cordless impact wrenches come with LED light which can provide illumination in the dark. This feature can come in handy if you are ever stuck in a car tire situation at night with no source of light.

Cordless or Corded

Electric Impact wrenches come in two forms, the corded type which requires an electricity source before it can be operated, and the cordless type which uses a battery as its source of power.

The advantage of the cordless type is that it is handier and can be used in a variety of situations where electric supply might not be available or in tight situations where moving the cord about might be cumbersome.

Size and Weight

The size of an impact wrench is a very important factor to consider before purchasing an impact wrench. The type of bolt or nut that the impact wrench can work with is determined by the size of the chuck drive.

Impact wrench of say 3/4 inch would work with bigger bolts found on trucks while the small 3/8 inch would work with smaller bolts found on home appliances.

If you are at odds as regards the size to go for, it’s best to go for the 1/2-inch size which can perform a wide variety of jobs and have a perfect combination of power, speed, and efficiency.

The weight of an impact wrench tells you how heavy the impact wrench might feel when you carry it. The bigger the size of the wrench the heavier it gets.

Brand and Reputation

With varieties of manufacturers out there producing impact wrenches, the choice of which product to go for becomes a herculean task. Generally, it is much safer and better to go for reputable companies that have been in the industry for a while.

When it comes to cordless impact wrenches, manufacturers like Milwaukee and DEWALT have proven themselves and are therefore a good option to choose from.

For Pneumatic wrenches, Ingersoll Rand is a good option considering they have been in the wrench niche since 1934. That’s a whole lot of experience if you ask me.

Key Takeaway

An Impact Wrench is a highly effective tool used by mechanics in the construction and automobile industries. With the proper training, even the most inexperienced home and vehicle owners can also use an impact wrench to avoid injuries.

There are several types of impact wrenches available, with significant differences in size, torque, and power source. Before purchasing one, it is important that you conduct thorough research to determine which type is best suited to your needs.

If you are unsure which one to get, you can always consult an expert to help you make your decision.

However, If you are a simple home or car owner, the 1/2-inch cordless impact wrench is your best bet due to its versatile operation and efficient combination of Torque and comfort.

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Jason D. Turner

Hi there! My name is Jason, a keen enthusiast in power tools and their mechanisms and the sole mastermind behind the Noisy Tools. Working in a multi-national construction firm in Brooklyn for over a decade, I have developed a fair flair for different construction devices, gadgets, and their diverse operational aspects. By the dint of this platform, I have researched and reviewed various tools with utmost details of even the most trivial matters that will provide valuable insights for any prospective user.

135 thoughts on “Types of Impact Wrench – Choose the best one for you”

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