Impact wrenches such as the electric impact wrench and air impact wrench, though most often used in removing vehicle lug nuts, are also used for removing engine parts where greater and more adjustable torque is required. Other applications include the use of these wrenches in construction and on assembly lines. Although both types of impact wrench are effective, there are differences between them. To understand some of these differences, refer to the information below.
Power that operates the air impact wrench is supplied by an air compressor, while power to the electric impact wrench comes from an electrical source such as commercial power or battery. Some authorities and testers, such as Gault Technology, rate the air wrench as superior when viewed from a power-to-weight ratio perspective.
2. Usable Features
Both types of impact wrenches operate the same in terms of the direction the chuck turns. Another similarity is these wrenches almost all require the pull of a trigger to turn the gun on. To shut off power, release the trigger. Optional features some of these wrenches offer is an additional handle mounted on the left side of the wrench. This handle provides extra holding power for the user.
3. Drive Size
Most impact wrenches, both electric and air powered, come with four drive sizes: one inch, ½-inch, ¼-inch and 3/8-inch.
4. Battery Power
Except for a heavy duty wrench which comes in a two-volt model, standard wrenches in both electric and air powered models are available with 16 volts or 18 volts. Wrenches operating from battery power are equipped with lithium ion batteries. These batteries retain a charge for longer periods of time than does the rechargeable battery and are especially useful where greater torque is needed.
5. Pricing Differences
You will find prices for wrenches of similar size and features can vary considerably, depending on brands. Owing to their portability, electric cordless wrenches usually have the highest price tags. In part, this portability affects pricing because the wrench does not require the use of an air compressor. Impact wrenches that fall into the lower price ranges are usually the air-powered models, while electric corded models are typically priced in the intermediate range.
6. What to Look for in an Impact Wrench
In evaluating the various models of impact wrenches, you should consider the drive size you'll need, along with the location you'll likely be working with the wrench. If you expect to do much moving or climbing, you will most likely want to invest in a battery operated model that can save you from having to pull an air hose or electric cord along with the wrench.
Another consideration is the length of time you'll be operating your wrench. If you plan to use it in sustained operation over longer periods of time, you will more likely need either an electric cord type wrench or one that is powered by air.
Finally, if you will require extra torque the air-powered model may better suit your needs. However, with this model, if you don't already have an air compressor, you will need to consider the cost of buying one, since air operated impact wrenches typically are not sold with the air compressor included in the price.