Electric impact wrench vs. Air impact wrench

Published: 05th November 2009
Views: N/A

What should I choose: an electrical impact wrench or an air powered one?

I was looking for a comparison between an air powered impact wrench and an electrical one. Not only technical specs, but a hands on review, if possible. Unfortunately, I found only different opinions, some leaning towards the electrical tools and some toward the compressed air ones. Obviously there was no other way than to put them both to work, and see the results.

The specs

What do those numbers mean?

Here things start to get confusing. Let's get each wrench and list the specs first then make some comments.

Milwaukee 2664-22:

Voltage: 18V

Anvil Size: 3/4" Square

Anvil Type: Friction Ring

Torque: 525 ft.-lbs.

RPM: 0-1,900

IPM: 0-2,200

Length: 9"

Tool Weight: 6.8 lbs.

Aircat Nitrocat 1000TC:

Drive (in.): 1/2

Average Air Consumption (CFM): 4

CFM at Load: 4

Speed - No Load (RPM): 7,000

Blows Per Minute (BPM): 900

Max. Torque (ft.-lbs.): 1,000

Working Torque (ft.-lb.): 200 - 800

Inlet Size (in.): 1/4

Min. Hose Size (in.): 3/8

Hammer Mechanism: Twin

Variable Speed: Yes

Noise Level (dB): 85

Tool Weight (lbs.): 4.5


Aircat Nitrocat 1000TC by BriskersAuto

Aircat Nitrocat 1000TC by BriskersAuto

Ingersoll-Rand air compressor by BriskersAuto


Anvil size, Drive: most widely used impact sockets for cars / small trucks are 1/2". 3/4" anvil inch might make the wrench look stronger, but in this particular case, it's not. Harbor Freight has a good adapter from 3/4" to 1/2".

RPM - it's actually the free speed RPM, not when the tool is under load. Notice that the Aircat 1000TC is more than three times faster. This speed shows how fast the impact wrench will take a bolt/nut out, once it breaks it loose. The faster the better. Watch the videos below to see the Aircat 1000TC in action!

IPM / BPM (impacts per minute, blows per minute) - how many times the impact mechanism hits in one minute. The faster the better, but actually after talking with a tech from Aircat about two of their models: 1000TC (twin clutch) and 1000TH (twin hammer), I found out that 1000TC, although with less BPM hits harder!

Torque: obviously the Aircat 1000TC has more torque.

Weight: the lighter the better, of course! The Aircat 1000TC is lighter and feels more comfortable after working extended periods of time. It is also a little shorter and it might fit better in tight places. The only drawback is the hose.

Case construction: Milwaukee 2664-22: plastic; Aircat 1000TC: composite (I think it's based on Kevlar). Composite is definitely better than plastic for durability, although both can get scratched.

Mechanism: Aircat 1000TC has a twin clutch making the wrench smoother and having less vibration.

Portability: here the Milwaukee 2664-22 is the absolute winner, and not only between these two impact wrenches, but on the market at this moment, in my opinion. It comes with two Li-ion batteries, fast charger, and the batteries keep the wrench operating at maximum power until they die. The tool will not lose torque until the batteries drain completely! Then, you can keep working with the second battery while you charge the first one. Also, the batteries are good for any M18 tool, not only for this impact wrench.

Noise level: the AIrcat 1000TC is quieter than the Milwaukee 2664-22, and it is probably the quietest impact wrench on the market today. It feels so silent comparing to other impact wrenches! Definitely a plus.

Variable speed: both impact wrenches have variable speed, the Milwaukee 2664-22 feels easier to control, maybe because it is electric.

CFM (cubic feet per minute): how much air the wrench uses. This is useful to match the tool with a compressor. Milwaukee 2664-22: n/a. Aircat 1000TC: 4. There is no comparison here really, as one wrench is electric; however a similar impact wrench from Ingersoll-Rand uses about 24 CFM at load! The Aircat 1000TC uses only 4 - 4.5 CFM. This makes is a good choice for a portable shop, as you can get away with a smaller air compressor.

The test

Let's get to work...

As a mobile auto repair, we need something portable and powerful enough to brake loose the crankshaft bolts and axle nuts. After comparing many electric impact wrenches, some of them corded, some cordless, Milwaukee stood out from the crowd, due to its 525 ft-lbs of torque and warranty. The fact that it is portable makes it even hotter. Not having wires or hoses laying around is a big plus.The 2664-22 looks like a wrench very capable to do the job. Also the 5 year warranty sounds very good. The only tool that was more powerful (but also more expensive) was the Makita TW1000. This is an corded impact wrench. Looking at the specs more carefully, I noticed that the 525 ft-lbs do not have a "direction": forward or reverse. In the description it's written "delivers 525 ft-lbs of torque". I decided that before spending $460 on it, I should check with the manufacturer exactly what they mean. After being transferred a couple of times due to the technical nature of the question, one of Milwaukee tech support specialists lets me know that the tool has 525 ft-lbs forward, so it's good to tighten at this torque. Of course my logical question was "how about reverse?" His answer was "I don't know...we don't test our tools in reverse... But for what you need, it should do the job. You also have 30 days to try it, etc. etc".

Excuse me? How come they don't test their tools in reverse? Thinking about the bolts and nuts in a regular car or even small truck: how many of them will you ever tighten at that torque? Yes, most likely none! How many times did you get stuck in the middle of a job because of rusty bolts or overtightened axle nuts, not to mention the nightmare of removing a crankshaft pulley bolt? Many times! So, actually the reverse is the most important detail, when we talk about power.

Considering the fact that Milwaukee lets you try their tools for 30 days, I decided to give it a try.

It feels very well balanced, the battery charged pretty fast, and the unit came with 2 batteries, so one can work with one battery while the other one is charging.

The job where I needed the wrench was a Honda timing belt change. I took the wheel nuts off with no problem; the mount screws came off easily, too. Then, when I got to the crankshaft screw, no luck! Tried one time, two times, ten times, nothing! The screw just wouldn't budge!

The wrench vibrates pretty much under load, you can feel the impacts in your hand. It is pretty loud, too, but as it turns out "noise doesn't mean power", as I would find out a week later.

We finally managed to get the crankshaft pulley screw off with a big handle, and about 400 lbs of weight. Clearly the guys from Pep Boys over-tighten these things a lot. That screw shouldn't have been tightened more than 200 lbs.

Next day I tried another pulley bolt, on an Audi. Same sad result: it didn't break it loose!

I really liked the wrench, but it didn't do the job I got it for! Sure, for small jobs like taking the wheels off, it's perfect. But if you need to get the "hard stuff" done, it will not do it. So, back to Milwaukee went for a refund.



After reading some reviews about Aircat 1000TC, I decided to call the manufacturer to confirm the specs: 1000 ft-lbs in REVERSE and 200-800 of tightening torque! Finally, somebody who thinks about testing their tools in reverse, too!

Actually, these numbers are at 90 psi, at 100 psi you get 1100 ft-lbs in reverse and 200-900 ft-lbs forward! The only problem left was finding a good air compressor, small enough to be portable but capable to deliver the required cfm and be reliable.



Talking on the phone with a tech from Aircat, I was assured that I could use a 4-5 Gal. compressor with the 1000TC. After comparing many air compressors in this range, I decided to get the Ingersoll-Rand DD2T2 14.5 Amp 2-Horsepower 4-1/2-Gallon Oiled Twin Hot Dog Compressor.

It is an oil-lubed machine, which for long term durability should be better than an oil-less one. Apparently it's also rated at 100% duty cycle, which is rare in this price range. My only complaint is that he tank is rather small; at 4.5 Gallons, you can't expect continuous use of the impact wrench, yet it's portable! As you can see in the video, the compressor needs some time to keep up with the gun, but the recovering time is pretty fast. Still, it's a nice machine and it does the job, even though you might need to wait a few seconds occasionally.

A couple of days later, thanks to Amazon Prime, both the Aircat 1000TC impact wrench and the Ingersoll-Rand DD2T2 compressor were ready to use. Just in time for another timing belt job.

"Noise doesn't mean power!" That's what Aircat guys warn you. First impression when using the impact gun was that it had a muffler. It is extremely quiet. Wheel removal is a matter of 10 sec. Crankshaft pulley bolt was removed in about the same time! I tried to remove another 2 pulley bolts and I didn't have any problem at all. Axle nuts, same speed. Watch the Youtube videos to see the Aircat in action. It is simply an amazing gun!

Conclusion

OK, so which one should I choose?

This really depends on a few factors.

1. If you can afford to get them both, then maybe you should. There are times when you need a cordless impact, and the Milwaukee 2664-22 is the perfect choice. Even without an outlet to recharge, you still have 2 batteries and they will be good for pretty long time to work. For a quick wheel removal, or even better when removing parts from a junk yard, you can count on it to do the job fast. Also, having two people, you can cut the time needed to do certain jobs in half when using both guns.

2. If you only light / medium work, again the Milwaukee 2664-22 will most likely be enough.

3. If you have heavy duty work or if you have to choose just one gun for everything in the shop, then the Aircat 1000TC is the way to go. Of course it is not that portable, you have the air hoses around, but you also have the power and the certainty that it can handle anything you throw at it!
Razvan Constantin

Briskers - The mobile Auto Repair shop
http://www.briskers.com


Video Source: Youtube


Report this article Ask About This Article


Loading...
More to Explore