Which Brand most powerful impact Wrench? “Inside: Air & Power Impact Wrench comparison sheet” (2019 version)
  • 2019-05-03

In last 5 years, 3 changes happened in air and power Impact Wrench Industry

1.) Thanks to structural improvement, the torque of the Air Impact Wrenches continues to grow to monster level
2.) Power Impact Wrench become more popular because of improvement in structure and battery life

3.) Compact Impact Wrench continues popular because of light and easy to carry in confine space


As a result, many tool brands keep introducing various pneumatic or power impact wrenches. Above chart shows Amazon's first page of impact wrench, you can see many pneumatic impact wrenches, power ones, or cordless ones.

Which one is more powerful, by power or by air?

The following table is a comparison sheet for maximum torque among different brands’ pneumatic impact wrench and power ones by each drive sizes in 2019. We chose these brands by our personal experience. Still many premium tool brands not include, so please email me if you got other data from missing tool brands. Email: service@tien-i.com


The chart shows two type Maximum Torques:

1.) Max Tightening Torque: the maximum torque of the impact wrench can output when tighten screw during test. The data should be collected in lab environment.

2.) Nut-Busting Torque: *Nut-Busting Torque refers to the tool's ability to remove a bolt tightened down using methods other than the tool itself. For Nut-Busting Torque, a bolt is tightened with a torque wrench calibrated to 1100 ft-lbs, then removed with the tool being tested.

Usually tightening torque is lower than removed torque. Because if tightening torque is too high, it would cause bolt damaged or stripped screw. That’s why when tighten the bolt, it will set up the fix lower torque to avoid possible damage.


The 1/4" impact wrench is rare because of the lower torque requirements. The maximum torque is 136 Nm, so far.

For example, for DIN/ISO impact socket 1/4"DR. x 13mm, the minimum torque requirement is 80.4 Nm. The good quality impact socket can achieve 1.5 times the minimum torque, which is 120.6 Nm. Impact Wrench torque 136 Nm could be very enough to drive all small size bolts or nuts.

3/8" Dr. (9.5mm)

Currently, 3/8" compact impact wrench is getting popular in the market, and many brands focus on introducing the lightweight models. It’s common to see in the auto shop. Do not underestimate compact models. For now, the compact model torque could reach up to 746 Nm. It is more than enough for 3/8"dr. impact sockets.

For example, impact socket 3/8"DR. x 25mm, ISO/DIN minimum torque required is 280 Nm. Good quality of impact socket can achieve 1.5 times torque tolerance, 420 Nm. Take 746Nm as given power, screw or even impact socket would be broken.

1/2" Dr. (12.7mm)

1/2" dr. impact wrench is king for now, no matter pneumatic or power ones, various style is available for choice, from compact to electric 18V to 20V. It’s higher difference among each brands’ maximum torques, from 186 to 1762 Nm. That’s because the range of 1/2” DR. the nut size big gap. The below table shows the relationship between nut size and the lowest torque of impact socket. The minimum size is 8mm (M5), but the maximum is 32mm (M22).

For example, the lowest torque value the 1/2" dr. impact socket size from 19 to 34mm could afford is 650Nm. Lets’ estimate 1.5 times value is about 975 Nm. In other words, even the large size 1/2" Dr impact socket, the impact wrench torque over 1000 Nm is likely to cause socket cracked.

Is it necessary to use such a higher torque?

For example, in the BMW tires auto shop, the standard of tightening tire torque is from 80 ft-lbs to 120. Converted to Nm, it is around from 108 Nm to 163 Nm.

By the way, some tire shops want to save time. Some operators directly use the highest torque of the impact wrench, which is dangerous. It could cause the screw collapsed or slipped. Moreover, to tighten with higher torque means to loosen the screw need higher torque as well. This cause two-time damage on bolts and screws. Maybe damaged on the screw is nothing, if you compared a fear of accidents when driving for a long time.


Above simple table is to easily show the torque among various brands’ power and pneumatic impact wrenches. However, if you need to buy an impact wrench, we suggest to consider following points:

1.) What Purpose? Is it for construction site, woodworking, or repairing a car? What is the maximum torque need for your tasks? It is not recommended to seek higher torque which you don’t need at all, and it costs a lot of money with heavier and bigger wrench body.

2.) What’s suitable body weight? Considering for long time use, please hold two bottles of water for one hour to see how you feel.

3.) What’s maintenance convenience, and warranty?

4.) What’s battery life (battery size)? When you work on the construction site all day, you don’t want to carry a bunch of batteries. If you don't know how to tell the spec of battery, you can simply remember that the two numbers: higher volts (V) and amp hours (Ah), better.

If you feel confused about the suitable impact wrench, please consult with the local hardware shop with good reputation, and ask for recommendation, and do more homework on brand comparison tests.

Our standard exceeds the European DIN/ISO and American ANSI torque requirement. We are happy to cooperate with various industries for new tool development. Please contact our sales team if you are interested in our quality impact socket business.

PS: This article is based on personal observation. Any mistake, please feel free to correct us by email: service@tien-i.com Tien-I has produced impact socket for high-level brands all over the world since 2003.


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