3/8 vs 1/2 impact wrench

by Joost Nusselder | Updated on:  March 12, 2022
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In the case of nuts and bolts, if your tools are not powerful enough, you will have difficulty with the heavier things. If you are facing such a situation, an impact wrench can be of great assistance. There are a variety of impact wrenches out there, but it is best to choose the one that suits your needs.

Among the most popular choices, we have chosen two of the most commonly used impact wrenches, which are 3/8 and ½ impact wrenches. In this article, we will compare the 3/8 vs ½ impact wrench to find out the best fit for you.


What Is An Impact Wrench?

Basically, 3/8 and ½ impact wrenches are classified according to the diameter of their impactor drivers. Though they both have almost similar functionalities, you cannot use them in the same field due to their different sizes, structures, power, and other features. However, before moving to the comparison part, let’s have a brief explanation about this tool. Because it is necessary to know what an impact wrench is to understand the comparison properly.

An impact wrench is simply a hand tool that creates torque after giving a sudden rotational impact. As the tool runs on electricity or uses specific batteries, you need very minimal effort in most cases and sometimes no effort at all. And, the simple function of an impact wrench works when the electric energy directly converts to rotational energy.

After getting the sudden rotational force on the shaft of your impact wrench, you can easily rotate your nuts and bolts. Not to mention, an impact driver is also known as an impact gun, impactor, windy gun, torque gun, air gun, air impact wrench, etc.

3/8 vs ½ Impact Wrenches

We’ve already mentioned that these two versions of the impact drivers are categorized, measuring their driver’s diameter. Now, we will compare them relative to one another.


First and foremost, the first difference between these impact wrenches is their sizes. Generally, a 3/8 impact wrench is smaller than a ½ impact wrench. As a result, the 3/8 impact driver is lighter and allows better handling than the ½ impact wrench. Though the size difference is tough to notice sometimes, it is obviously a considerable thing when choosing between them.


The compact size of the 3/8 impact wrench helps to fit in tighter areas, and you can use it for small nuts and bolts. To be precise, you can remove 10 mm or less sized bolts effortlessly using this tool. So, it can be a great tool when you are in need of more acceptable accuracy and precision.

However, you can choose the ½ impact wrench for higher power and precision. Actually, the ½ impactor falls in the middle of the chart when we compare all sizes of the impact wrenches. So, basically, it comes with enough driver size to handle bigger nuts and bolts, which you cannot do properly using a 3/8 impact driver.

Though the ½ impact wrench has more power, you are worry-free about getting a controllable force. Generally, the ½ impact driver ensures the safe removal of nuts and bolts. Although this may be true, a 3/8 impact wrench also works perfectly for small-sized bolts and nuts.


We don’t need to mention again that the ½ impact wrench is more powerful than the 3/8 impact wrench. Mostly, the ½ is suitable for heavy-duty projects and gives a higher torque. In this way, you will get higher pressure output from the wrench.

If we take a regular ½ impact wrench to test the output power, it generally goes up to 150 lbs-ft starting from 20 lbs-ft, which is a massive amount of force for wrenching tasks. Using such power, you can remove and drill the nuts as well as complete other similar rigorous tasks using this impact wrench.

On the other hand, the 3/8 impact wrench comes with low power output. And, it cannot withstand heavy conditions. Using this impact wrench, you may get up to 90 lbs-ft of force starting from 10 lbs-ft, which is quite low compared to the ½ impact wrench. So, the ½ impact wrench is a preferable option when you are looking for precision over power.


Let’s say the 3/8 is usable in only smaller forms of works like zip nuts, woodworks, DIYs, and other similar projects. The compact design of this product is considered ideal for simple precision jobs.

On the contrary, you can use the ½ one in construction works, industrial maintenance, automotive tasks, suspension works, lug nut removals, and other hefty jobs like these. This performance becomes possible only because of its higher level of power and torque. So, it is better not to choose the ½ impact wrench when you are not a professional or attached to any kind of heavy work.


Specifically, you won’t get the same design for different models of the same size. Similarly, the 3/8 and ½ impact wrenches are available in many designs and models that are offered by different companies. Usually, the structure looks like a gun, and you can hold it easily to get a good grip.

The typical build design includes a push-button system for both sizes. You need to push the trigger to start running the impact wrench and release the trigger to stop it. Besides, both of the impact wrenches come with LED flashlights and display monitors. However, the significant difference in design between the 3/8 and ½ impact wrenches is their driver sizes. Though most things are similar in both impact wrench designs, the driver size is always bigger in the ½ impact wrench.


After knowing all the related things, we can suggest you get both products if you are a professional. Because, you will be able to work in both cases whether you need precision or power. However, if you are only interested in one side, then you can choose one.

For simple tasks, a 3/8 impact wrench provides the best precision control, while the 1/2 impact wrench is best for heavy-duty applications requiring high power.

Also read: these are all the different adjustable wrench types and sizes you might need

I'm Joost Nusselder, the founder of Tools Doctor, content marketer, and dad. I love trying out new equipment, and together with my team I've been creating in-depth blog articles since 2016 to help loyal readers with tools & crafting tips.