How to Choose the Best Impact Wrench for Your Application

There are so many different impact wrenches on the market that it can be difficult to know what to look for when choosing one. This guide gives a brief overview of the technology and puts together some simple steps to help you get started.

Familiar with mechanical structure

An impact wrench, also known as an impact screwdriver or impact gun, is a tool designed to quickly tighten or loosen bolts. It is widely used in the mechanical and industrial fields, such as changing tires, removing wheels, or maintaining oil platforms. According to different needs, impact wrenches can be divided into electric, battery-powered and pneumatic types, each with its own unique advantages and disadvantages.

Its working principle is relatively simple. The impact mechanism consists of an impact shaft, an impactor (impact hammer) and a spring, which enables the wrench to flexibly cope with tightening and loosening operations. The tool accumulates energy through one or more turns of the hammer cage. When the impact hammer hits the output shaft, a strong tightening or loosening torque is generated.

Assess your needs

Remember, there is no one-size-fits-all solution. The required torque range, power requirements and design of the impact mechanism will vary from job to job. The latter will affect the tool’s weight, vibration, speed and durability, and therefore have a considerable impact on user comfort and suitability for the task. To begin the selection process, first consider:

What features of a tool are important to you: power, efficiency, ergonomics, freedom of movement, or versatility?

Your environment: How will you power the tool?

Torque: Range and precision, what does your application require?

Product ergonomics: Are vibration and noise levels, tool design, and suggested accessories appropriate for the job?

Clutch type: Does the mechanism deliver the power you need?

Tool weight and material: Is it fatigue-free over time, and does the material match your work environment?

Learn more about tool design

The design of a tool can play a major role in improving productivity. For example, a well-positioned center of gravity is a significant advantage because it provides better support over a longer period of time, while different handle shapes and trigger locations can improve user comfort.

Remember that materials have a huge impact

The material of the tool is another important consideration. Metal tools are generally stronger, but the weight is not suitable for long-term use. Composite tools are relatively light, which allows for better maneuverability, but the material makes them less durable. Fortunately, advances in material development over the past decade have improved the mechanical resistance of composites, increasing their strength and allowing them to replace metal in many applications.

Keep in mind that the clutch housing and tool body can be made of different materials. When you compare tools, always check which part is composite and which is metal. As a rule of thumb, PWRTOOLS ¾" impact wrenches are usually made of metal parts.

Get the Right Torque Level

Always choose a tool with a higher upper torque limit than your application requires. This will reduce the time you spend using the tool and the vibrations you experience. The chart below shows different torque values commonly found in manufacturers' catalogs.

How to Choose the Best Impact Wrench for Your Application

Are you using the right impact wrench?

Legend:

A: Tool torque range

B: Time

1: Ideal torque: From this torque range, this tool is a suitable choice to ensure excellent productivity. Especially suitable for intensive use.

2: Working torque: Make sure the tool's working torque range covers the torque required for your application.

3: Upper torque limit: To be able to use frequently at this torque level, we recommend that you choose a more powerful tool to improve productivity and operating comfort.

Kindly reminder: Beware of over-tightening! In some applications, such as when changing tires on small vehicles or trucks, tightening requires accuracy and torque control. Using a tool with a torque-limiting function in combination with a torque wrench will optimize the application without over-tightening and damaging the studs.

Check Bolt Size

You can determine the ideal tool square by looking at the size of the threads. If the square is too small compared to the threads, it will not fit and the square may break. However, if the square is too large, it will be too powerful and break the bolt when tightened.

Don’t overlook ergonomics, noise and vibration

It is important to pay attention to factors that affect user safety and ergonomics, such as noise levels and vibration. Noise levels are usually referenced to the ISO15744 standard, and the lower the number, the safer the user experience. The same is true for vibration levels. Some impact systems are designed to achieve lower vibration levels, and vibration-damping gloves can further enhance safety and comfort.

By considering these seven points, you will improve the safety associated with using tools on the job, thereby protecting the operator. Another benefit of these responsible practices is that you will also improve efficiency!

Try it out

When searching for the right impact wrench, understanding the key considerations is a good start, but technical specifications alone may not lead to an informed purchasing decision. It is recommended to communicate your specific needs with the manufacturer and request a trial tool. Trying the impact wrench in the target application ensures its suitability for the task and environment, while also confirming that it fits the way you work. This hands-on experience will help you make a more informed choice.