What Is an Impact Gun? Impact Gun vs Impact Wrench Explained
An impact gun is a power tool, formally called an impact wrench, that uses rapid hammer blows to loosen and tighten nuts and bolts. This guide explains the name, the mechanism, the main power sources and the safe way to choose one for workshop work.
In This Article
- 01What is an impact gun?
- 02Why the same tool has two names
- 03How an impact gun works
- 04Air, cordless, corded and hydraulic types
- 05Impact gun, wrench and driver compared
- 06How to choose for workshop work
- 07Sources and specification notes
- 08Frequently asked questions
What Is an Impact Gun?
An impact gun is a power tool, also formally called an impact wrench, that uses rapid hammer blows to loosen and tighten nuts and bolts.
There is no difference between the two names, but catalogues and standards use “impact wrench”, so that is the clearest term to use when specifying a tool or requesting a distributor quotation.
Why the Same Tool Has Two Names
“Impact wrench” is the formal name; “impact gun” is the workshop and search-language name.
- Dictionaries define the tool as an impact wrench: an electrically or pneumatically operated wrench that delivers a rapid succession of sudden torques.
- Standards use the same terminology; ISO 2725-2 covers machine-operated impact square-drive sockets.
- “Gun” describes the familiar pistol-grip and trigger shape.
- Search behaviour uses both names side by side, so explaining the equivalence helps buyers find the right tool.
Which Name Should a Buyer Use?
Use “impact wrench” on purchase orders and quotation requests. Add the drive size and power source—for example, “1/2 in. air impact wrench”—to avoid confusion with other tools called guns.
How an Impact Gun Works
An impact gun spins an internal hammer, lets it build up speed, then strikes an anvil to deliver short, powerful bursts of torque.
Inside the tool, the motor accelerates a rotating mass, then suddenly connects it to the output shaft. The square drive on the anvil holds the socket. Because torque arrives in blows rather than one continuous twist, the operator feels less reaction through the handle than when using a ratchet or breaker bar.
For a closer look at the mechanism, see How an Air Impact Wrench Works.
Types of Impact Gun: Air, Cordless, Corded and Hydraulic
Impact guns are grouped by their power source: compressed air, cordless battery, corded mains electric and hydraulic.
Air Impact Gun
Air is common in workshops because the tool can be compact and light for its output. It requires a compressor and air line capable of supplying the pressure and airflow specified for the model. Browse the M7 air impact wrench range.
Cordless Impact Gun
Cordless impact guns remove the hose and cable, making them practical when the work moves. Modern brushless motors and lithium-ion batteries suit many automotive and maintenance jobs. Browse the M7 cordless impact wrench range.
Corded Impact Gun
Corded models suit fixed areas with electricity but no compressed-air supply. They avoid battery management, but cable reach and safe cable routing remain part of the job.
Hydraulic Impact Gun
Hydraulic impact guns are used where high-speed hydraulic power is already available. They are more common in heavy-equipment and industrial environments than in a typical tyre bay.
For a practical comparison of the main power sources, read Air vs Electric vs Cordless Impact Wrench: How to Choose.
Impact Gun, Impact Wrench and Impact Driver Compared
Impact gun and impact wrench name the same tool; an impact driver is a genuinely different tool category.
| Name | What it is | Output end | Typical work |
|---|---|---|---|
| Impact gun | Informal name for an impact wrench | Square drive for sockets | Nuts and bolts, including wheel nuts |
| Impact wrench | Formal catalogue and standards name | Square drive for sockets | Nuts and bolts, including wheel nuts |
| Impact driver | Separate tool category | Holder for smaller bits | Screws and smaller fasteners |
Can an Impact Driver Replace an Impact Gun?
Not for larger nuts and bolts. An impact wrench accepts sockets and is designed for larger fasteners; an impact driver is the better choice for driving screws with compatible bits.
How to Choose an Impact Gun for Wheel Nuts and Workshop Work
Work back from three questions: what you are fastening, how long the tool runs each day and what power is available on site.
What Are You Fastening?
The fastener helps determine the drive size. A 1/2-inch impact wrench is a common starting point for general automotive and workshop work; larger drives suit larger fasteners and equipment. Match the drive to the socket and fastener requirement. See the M7 drive size guide for 3/8 in., 1/2 in. and 3/4 in. context.
How Long Is the Tool in Use Each Day?
Continuous workshop use and occasional jobs call for different tool grades and power arrangements. A tyre bay operating all day has different requirements from a maintenance kit used a few times each week. Tell the distributor about expected duty time and the fasteners involved.
Which Power Source Suits Your Site?
Choose air where the workshop has a correctly supplied compressor and air line; choose cordless when there is no compressed air or the work moves around. A fixed tyre bay and a mobile fitter will often make different choices.
Do You Have the Right Sockets?
Use impact-rated sockets only. Standard hand sockets may not be designed for impact loading and can fail. Choose sockets specifically rated for impact tools; see the M7 impact socket range.
How Should You Tighten Wheel Nuts?
Run wheel nuts down with the impact wrench, then perform final tightening with a calibrated torque wrench set to the vehicle maker’s specification. Do not rely on an impact wrench alone where a specified final torque matters. See the M7 torque wrench range and the torque wrench guide.
Sources and Specification Notes
- Merriam-Webster: “impact wrench”
- ISO 2725-2: Machine-operated impact square drive sockets
- Wikipedia: Impact wrench
- M7 official air impact wrench range
- M7 official cordless impact wrench range
Information verified: 21 October 2026. Product specifications and availability may change; confirm the exact model on its official M7 product page before purchase or use.
Frequently Asked Questions
What Is an Impact Gun?
An impact gun is a power tool, formally called an impact wrench, that uses rapid hammer blows to loosen and tighten nuts and bolts through a square-drive socket.
Is an Impact Gun the Same as an Impact Wrench?
Yes. Impact gun is an informal name for an impact wrench. Catalogues and standards use “impact wrench”.
Is an Impact Gun the Same as an Impact Driver?
No. An impact driver takes smaller bits for screws, while an impact wrench is built for larger nuts and bolts with sockets.
Is an Air Gun the Same as an Impact Gun?
Not always. “Air gun” can mean a pneumatic impact wrench, but it can also refer to an air blow gun used for cleaning. Ask for an “air impact wrench” to avoid confusion.
Can I Use Normal Sockets on an Impact Gun?
No. Use sockets specifically rated for impact tools. Standard hand sockets may not be designed for impact loading and can fail.
Do I Still Need a Torque Wrench If I Have an Impact Gun?
Yes, where a specified torque matters, such as wheel nuts. Use the impact gun to run fasteners down and a torque wrench for final tightening.
What Should I Ask a Distributor For?
Ask for an impact wrench and state the drive size, power source—air, cordless or mains—and the torque range needed in Nm and ft-lb.
