What is an Impact Wrench?

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An impact wrench is a power tool used to deliver high torque output with minimal effort by the user. It is commonly used in automotive repair, heavy equipment maintenance, product assembly, and other types of high-torque projects.

The most important feature of the impact wrench is its torque. The torque of the impact wrench is produced by the epicyclic gear system. It is typically measured in Newton meters (Nm) or foot-pounds (ft-lb). There are two main types of torques in the impact wrench such as tightening torque and breakaway torque. The RPM measures the speed of the impact wrench.

Impact wrench collet holds the socket for tightening and losing tasks. Impact wrenches have two main types of collets such as quick change collet and friction ring collet. Quick change collet is easy to use, while hog ring collet is safer than quick change collet.

According to the power supply of the power tool, impact wrenches are mainly 3 types such as pneumatic impact wrenches (powered by compressed air), electric impact wrenches (powered by electricity), and hydraulic impact wrenches (powered by hydraulic oil). Among these the hydraulic impact wrenches have minimum noise with maximum torque than the other two types.

An impact wrench torque is produced by the torque multiplier mechanism with a planetary gear system. The number of impacts of the impact wrench is measured by the Impact per Minute (IPM). The higher IPM is more powerful. When the impact mechanism is activated, it will be 100-105 dB. Hence, an impact wrench is a noisy tool.

The advantages and disadvantages of impact wrenches depend on the tool’s performance, power supply, and user experience. If you do not use an impact wrench properly, you can observe many problems, such as overtighting the lug nut, under-tighting the lug nut, higher impact noise, higher vibration, workpiece damage, and wear and tear in the tool. An impact wrench can be overheated, reducing performance when its inner heat is high. In order to prevent these, you should use the impact wrench properly.

What is the Torque of the Impact Wrench?

The torque in an impact wrench refers to the force that the wrench uses to rotate an object around an axis or pivot point. It is typically measured in Newton meters (Nm) or foot-pounds (ft-lb). The higher the torque, the higher the tool’s capacity to undertake heavy-duty tasks such as removing nuts or bolts that are extremely tight. There are two main types of torques: tighten torque and breakaway torque.

  1. Tightened torque (forward torque) – The tightened torque is the torque for tightening the lug nut.
  2. Breakaway Torque (reverse torque) – When you need to lose the nut, you will need more torque than high torque. This is breakaway torque. That is always less than the tightening torque. Breakaway torque is the maximum torque that a tool can produce.

Impact wrench torque can be measured as in-lb (Impact driver) or ft-lb (Impact wrench). You can convert each other using this. 1 ft-lb = 1.3558 Nm = 12 in-lb

You can see some tested dates for Milwaukee, Rigid, Dewalt, Ingersol rand, and AC Delco as below.

Tool with PriceForward Torque (psi)Backword Torque (psi)
Milwaukee (156$)17502000
Rigid (168$)15001725
Dewalt (143$)9001000
Ingersol Rand (190$)675650
Delco (96$)450275

What is the Speed of the Impact Wrench?

The speed of the impact wrench is defined by the rate at which it can rotate or spin. Typically speed is measured in RPM (revolutions per minute). It influences how quickly the wrench can tighten or loosen fasteners or bolts.

Higher speeds impact wrenches generally allow for faster completion of tasks. Some impact wrenches come with adjustable speed settings for greater control over different applications. Impact wrench uses an epicyclic gearing mechanism. Therefore when its speed is reduced, the torque is increased.

What are the 2 Types of Impact Wrench Collets?

The impact wrench collet is a component of the impact wrench that holds the socket or bit in place. The impact wrench collet is a part of the tool that you attach the socket to in order to carry out your work. Most impact wrenches collet sizes are 1/4″, 3/8″, 1/2″, and 1″. 1/2 and 1″ are used for extremely heavy-duty works in industrial level usage. Impact wrenches have two main types of collets such as quick change collet and friction ring collet.

  1. Quick change collet – This type of collet (pin detent) allows for quick and easy changing of bits without the need for any additional tools.
  2. Friction ring (Hog Ring) collet – This type of collet is designed to hold the socket with a steel ring in the square driver. It allows for a stronger grip and is ideal for heavy-duty applications. However, changing sockets might require more effort compared to the quick change collet.

There is a difference between friction ring vs pin detend impact wrenches. Hence you should know this before select an impact wrench.

What are the 3 Main Types of Impact Wrenches

There are 3 main types of impact wrenches according to the way of power supply.

1. Pneumatic Impact Wrenches

Those tools are used for extremely high torque requirements. Compressed air is used to power up the tool. Pneumatic impact wrenches are used in garages, industrial usage, etc. Compressed air is supplied using the hose, and when it moves through the impact wrench, it releases the compressed air power by rotating the tool. Those are with high noisy high power.

2. Electric Impact Wrenches

Electric impact wrenches are mostly used for domestic purposes. Electric impact wrenches are mainly two types according to its power supply. Those are corded and cordless electric impact wrenches. Corded impact wrenches are more powerful than cordless. But these are not portable. Cordless impact wrenches are powered by the Li-Ion rechargeable batteries. These are portable and can be used for any DIY or professional task.

3. Hydraulic Impact Wrench

The power source for the impact wrenches is hydraulic. It is used to achieve proper tightening or loosening of a connection. A hydraulic torque wrench is significantly quieter, lighter weight and more accurate than pneumatic impact wrenches capable of similar torque output.

How Does an Impact Wrench Work?

An impact wrench is used to lose or tighten the lug nuts, which requires more torque tasks. Therefore impact wrenches need more torque for the tasks. When considering the impact driver, there is a rotational hammering mechanism that helps to produce the torque for the driving process. That much torque is enough for driving screws inside the wood.

But when we consider the impact wrench, we need more torque.

How does it produce that torque by using the same tool? There is an amazing engineering solution called torque multiplier. The torque multiplier is the main mechanism that is added to the impact driver mechanism.

Torque Multiplier – A torque multiplier is a combination of a gear system. It is named planetary gears. Epicyclic gearing mechanism can control the gear ratios and then change the torque. According to the rotational speed, torque can be controlled. That is more than the impact driver. There is no such mechanism in the impact driver.

The number of impacts is measured as impact per minute (IPM)

Epicyclic gear system
Epicyclic gear system

Finally, the impact driver produces more torque using the epicyclic gear system.

What is the Noise Level of Impact Wrenches?

Impact wrench noise is 92-97 dB when the impact mechanism is not activated. When the impact mechanism is activated, it will be 100-105 dB. The suitable noise level is 85dB therefore, using an impact wrench is a bit noisy.

What are the Advantages and Disadvantages of Impact Wrench?

The advantages and disadvantages of impact wrenches depends on the tool performance, power supply, and user experience. These are the advantages and disadvantages of the impact wrench.

Advantages of Impact Wrench

  1. Impact wrench has a high torque output.
  2. Impact wrenches are efficient and fast-operation
  3. Impact wrenches reduce user fatigue.
  4. Impact wrenches are versatile for a variety of tasks.
  5. Impact wrenches are durable and long-lasting.
  6. Easy to use and operate
  7. Portable and compact for easy storage.

Disadvantages of Impact Wrench

  1. Impact wrenches are expensive to purchase and maintain.
  2. Impact wrenches can damage screws and bolts if not used properly.
  3. Impact wrenches can be quite heavy and bulky.
  4. Impact wrenches require a power source, limiting mobility.
  5. Impact wrenches are noisy and disruptive.
  6. Impact wrenches require safety equipment to use safely.
  7. Impact wrenches are not suitable for delicate or precision work.

What are the Problems of Using an Impact Wrench?

Impact wrench problems can arise due to the force, noise, vibration, and user experience it generates. These are the common problems can be seen while using an impact wrench.

  1. Over-tightening the lug nut – The most common problem with using an impact wrench is over-tightening. This can lead to stripped threads, broken bolts, or damaged equipment.
  2. Under-tightening the lug nuts – Impact wrenches can also under-tighten bolts if it is not powerful enough for the job or if the operator does not apply enough force.
  3. Higher impact wrench noise – Impact wrenches noise is generated by the hammering action of the wrench, which creates a loud, repetitive noise that can be disturbing to others.
  4. Higher impact wrench vibration – The hammering action of an impact wrench also generates significant vibration, which can be uncomfortable or even harmful to the operator over time.
  5. Damage to the workpiece – An impact wrench can easily damage the workpiece if not used carefully.
  6. Wear and tear on the impact wrench tool – Impact wrenches are subject to a lot of wear and tear due to the high forces they generate.

In order to prevent most of the impact wrench problems you should grease the impact wrenches properly.

Why is My Impact Wrench Overheat?

An impact wrench can overheat due to these 7 reasons such as.

  1. Continuous Using of impact wrench
  2. Applying maximum load on impact wrench
  3. No lubricants in the impact wrench
  4. The carbon brushes of the impact wrench has worn out
  5. Impact wrench ventilation are covered
  6. Impact wrench is using in a sunny area
  7. Wrong battery is used in the impact wrench

Tom Mackency

Tom Mackency

Hi, I am Tom Mackency. It has been 10 years that I have been working as a professional woodworker since 2013. I am really enjoying my carrier by creating many kinds of projects in my workshop. But mostly I like for home improvement projects. Home improvement and DIY projects are the most interesting things for me. More than that, the coolest things are power tools. Those are very precious and efficient than a decade ago. So I try to introduce so many things about power tools, woodworking, DIY projects, home improvement and many more interesting topics here.