Air Impact Wrenches

Air impact wrenches – also known as pneumatic impact wrenches – are powerful tools designed to deliver high torque output with minimal effort from the user. Commonly used in automotive workshops, construction, and heavy-duty maintenance tasks, these tools are essential for quickly loosening or tightening stubborn bolts and fasteners.

At Pipestock, we supply a range of high-quality air impact wrenches suitable for both trade professionals and DIY enthusiasts. Whether you're removing wheel nuts or working on industrial machinery, our pneumatic tools deliver the performance and reliability needed for the job.

An air impact wrench – also known as a pneumatic impact wrench, rattle gun, or torque gun – is a type of powered tool used primarily for tightening and loosening threaded fasteners such as nuts and bolts. Unlike a standard socket wrench or spanner that relies solely on user strength, an air impact wrench delivers sudden, high-torque rotational force generated by compressed air, allowing for fast and efficient removal or tightening of even the most stubborn fixings.

Key Characteristics:

• Square Drive: Most air impact wrenches feature a square drive (e.g. ¼", ⅜", ½", ¾", 1"), which is designed to accept sockets. The size of the drive directly relates to the tool's torque output and suitable applications.
• Impact Mechanism: Unlike drills or rotary tools, impact wrenches feature a hammer-and-anvil mechanism that delivers high-torque bursts rather than constant rotation.
• Power Source: Air impact wrenches are powered by an external air compressor, which supplies compressed air via a hose, typically at 90 PSI (6.2 bar). This makes them exceptionally reliable in industrial settings, as they don’t rely on batteries or electric motors.

Air impact wrenches use compressed air supplied from an air compressor to drive an internal hammering mechanism. This mechanism builds up rotational energy and delivers it in short bursts (impacts) to the output shaft. This method allows the tool to provide exceptionally high torque without transferring excessive reaction force to the user’s hand. Here's a step-by-step explanation:

1. Compressed Air Input: Compressed air is forced into the wrench's cylinder from the compressor.
2. Motor Rotation: The incoming air causes the motor's rotor to spin rapidly. 
3. Energy Storage: The spinning rotor accelerates, storing kinetic energy. 
4. Hammer Mechanism Engages: As the rotor spins, it drives a hammer. The hammer is often mounted on a cage or has a spring and cam system that allows it to slide down a spiral path on the driving shaft. 
5. Impact Delivery: When the hammer is forced off the cam, it slams into the anvil, which is connected to the socket. This action is the "impact". 
6. High-Torque Output: The impact releases the stored energy in a sudden, high-torque burst, twisting the fastener. 
7. Free Rotation: The hammer then spins freely again until the cam engages it to reset for the next impact. This cycle repeats, delivering a series of powerful blows to the fastener. 

Regular maintenance is key to prolonging the life of your air impact wrench and ensuring consistent performance. Here are essential maintenance tips:

• Daily oiling: Use pneumatic air tool oil (such as ISO 22) before and after use. Simply add a few drops into the air inlet to lubricate internal parts. Alternatively, use an in-line lubricator or filter-regulator-lubricator unit to maintain clean and lubricated airflow.
• Check air lines: Ensure hoses are free from leaks, kinks, and moisture. This is also vital to ensure user safety.
• Drain compressors daily: Prevent water vapour from entering and corroding the tool and rusting the compressor tank.
• Store properly: Keep the tool in a dry place and ideally in a case when not in use.
• Avoid over-torquing: Use torque sticks or appropriate pressure regulation to avoid damaging fasteners and the tool itself.