Some questions about impact tools

There very well might be threads around discussing this, but “impact” is such a general term with multiple meanings that it’s hard to search for. I also have a couple of very different Q’s… But feel free to just send me link(s) to discussion(s) if it(they) exist(s).

Keep in mind that I am a DIY’er and anything I have in the category of impact tools gets occasional use. I’m not beating the crap out of things all day every day.

I currently have an air impact. It’s an “ok” tool - 1/2" Ingersoll Rand. It maxes out at about 700, and I’d rather have something with more torque. I bought it probably 10 yrs ago(?) as the strongest one I could find at the time that my compressor could handle. (21gal, 6hp, 6.0cfm @ 90psi. The IR spec is 5.5cfm @ 90).

One question about that - it’s spec’d for 3/8" line. So I set it up with 3/8" fittings on a 3/8" hose. But why does it seem more typical to have 1/4" fittings on air tools with a 3/8" hose? Common sense tells me that if a 3/8" hose is spec’d than the fittings should also be 3/8." But what do I know? Does it either help or hurt to keep the fittings smaller than the hose?

But I guess the real question is that there are apparently great options for cordless impacts these days that have great torque. It’s not that big of a drag to pull out the air hose and whatnot, but a cordless would just be so much easier.

Especially for the pros who do beat the crap out of their stuff every day (but obviously for anyone else) , do you have one? What do you have? Anything to recommend? I already own a decent line-up of Milwaukee M18 tools, and I’m sure they make a good one that would at least make it to 1,000-1,200 ftlbs? Anyone have a Milwaukee? Their website is really hard to search on the basis of power. Just pictures with no specs. I don’t have hours to click into every darned model and find the specs.



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I have both air and battery 1/2 impacts. Neither have the power you want. The air is more compact than the battery and if I need more torque I can increase pressure. Nothing to do with the battery.

The air is Campbell Hausfeld. Over 40 years as a DIYer this is my 3rd air impact and 2nd C-H. I think it is 500 ft lbs but not sure. I can’t think when I needed more than 115 psi into that gun to bust something loose.

I have a 3/8s air ratchet but rarely use that. My 1/4 hex battery impact gets used with 1/4, and 3/8s socket attachments and it can be pretty handy for low power stuff. B and D brand.

I’d like a battery ratchet but I had a Craftsman air ratchet and did not use it much.

For cordless tools if I’m not buying Snap On I’m buying Milwaukee. That’s just been my personal experience. I’ve tried other brands but those 2 have given me the best bang for the buck as far as reliability, battery life, and power.

I know you’re not a pro, but remember cordless impacts can get pretty heavy if you’re using them for an extended period, like under a truck pulling a trans. Despite the fumbling with hoses, I still prefer air tools.

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Now that’s what I’m taking about - 1,600 lbs. “nut-busting” torque. Thanks @Tester

That was actually another question that I didn’t ask. The typical rule of thumb is 90 psi on air tools, but you can ramp up the pressure. (I know from checking that w/ 50’ of 3/8" hose that I need my regulator set to 100-110-ish to get 90 at the tool). But how much can you crank the pressure?

I’ve never tried to measure what I needed and 80% of the time I’m just changing tires, so the 110-ish is fine. But the IR struggles sometimes on higher torque things like, e.g., old rusty stuff, caliper bracket bolts, esp if rusted and/or blue-threadlocked. And the like.

And…I’m haunted by an “episode” (long time ago now) where I just needed to change out a half-shaft and couldn’t get the axle nut. My impact at the time (some Kobalt thing from Lowe’s) wouldn’t do it. I then literally broke a 1/2 breaker bar (using a long pipe extension) trying to get it. Finally drove it to my local shop and asked if they could just bust it loose for me. And, you know, the guy just put his impact on it - whack whack whack - and there it went. And he said “it’s all about the air.” ? A two minute thing turned into an all day thing for me there.

99% of the time, I’m set up fine. But I was thinking if I want to go cordless, I’m going as big as I can, I guess, for that 1% of the time.

Awesome. Thank you. Since I’m into the M18 already I’ll lean toward the Milwaukee. And I’ll never get rid of the air, so can always go with the hose and less weight when needed. But really useful info. Thanks.

Do you have a regulator/oiler feeding your pneumatic tools from your compressor?


And if not, do you add oil to the tool prior to operation?


I have a regulator and a filter/dryer, but not an oiler. But I always oil before using any of the tools with moving parts - certainly the impact. 3-4 drops of oil before using and I’m not shy about adding some more if it turns into a marathon.

As much as your compressor and regulator can supply! Mo Powahhhhh!
You are right to consider the size of the airlines and fittings. I prefer to use as big and consistent of fittings as possible. More air pressure can help overcome that but isn’t efficient.

Keep in mind that you are not assembling cars here so the total volume of air is not terribly important for an impact wrench. A small compressor might run a bit low but you can wait a moment until it refills the tank. Total output is more a problem with spray painting, grinding, paint buffing/sanding than impact tools because of the constant demand. My compressor runs continuously if I am using my air-buffer to polish a car but not when I’m impact wrenching the wheels off.

The electric tool gets larger and heavier for every job just for the 1% that needs the extra grunt. And it’s a double hit… bigger motor AND bigger battery. You might get tired of that after a while.

I’d just buy a bigger air impact if the additional pressure can’t 'git 'er done".

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Since I’m a public employee and don’t “flag hours” I use mostly air tools

I’ve been let down too many times with cordless batteries, plus they can get pretty expensive, to the point you may be better off buying a whole new kit, if a battery fails and needs replacement

As long as the air compressor is working, the air tools have been quite reliable

I have both Snap on and Ingersoll Rand air impacts, but I feel Ingersoll Rand has slightly less power, but is also slightly more reliable


I thought 1/2" drive was limited to around 400 foot pounds. How are they advertising a 1/2" impact that does 3 to 4 times that?

Not much in the way of experience , but I’d guess the best compromise for a diy’er already owning a compressor is the air-tool route. Not as convenient as electric, but more compact so may be easier to get it into tight spots, and not as expensive either. You can use the money saved to purchase differently configured air versions as well, 90 degrees, maybe one w/less force but smaller, etc.

Do you have a specific use for this tool in mind?



That IR would be a great choice if money was no object or you were a pro.

That is some nut bustin’ torque!

$380 almost seems like a bargain for something like that.

This one’s no joke either: W7152 20V High-Torque Cordless Impact Wrench| Ingersoll Rand

Just convenience. Let’s say I have to just pull a wheel b/c I have a leak and want to drop it at a shop. To haul out the hose and impact and oiling and yada yada to pull one wheel is a drag. Obviously I can just do it by hand - and will if that’s all I’m doing. But I also sometimes like to use my concrete patio for jack/stands as my drive is gravel. I have 50ft of hose on a reel that barely makes it, and then only if I’ve gotten the car in the right spot on the patio. Obviously I can add more hose, and have at times. But if all I had to do was pick up one thing (2 including the socket) and take it anywhere I want…it’s convenient.

But more to the point? I like power tools. :stuck_out_tongue: (panting). And I have a set of M12 and M18 already - they both include impacts, but those are just the drill/driver type. IDK what kind of torque they have but they aren’t suitable for auto work.

Ever have to remove the crank bolt from a Honda?


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It does seem like a great tool. But Diy’er economics are different than what’s best for a pro-mechanic. If a diy’er could purchase a less robust tool but otherwise w/the same specs for half that amount, and it failed after only a dozen uses, the less expensive one still might be the better option. On the other hand if a pro-mechanics tool fails mid-job and they can’t finish a customer’s car on time, that could easily cost the mechanic more than $380 in future business.

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Most home use air compressors such as my 30yo 5HP 60gal are set to 90PSI, I have never had to turn it up for my IR impact… But most Pro shops run pro air compressors with the air pressure set at around 170 psi… in my area anyway…

Almost every shop, including my own (back in the day), pro shops use a 1/4" air coupler/nipple M-style, kind of industrial standard in my area anyway for shops, so if/when mechanics relocate to another job/location they don’t have to buy all new air nipples for all their air tools… and most bigger shops will use a 3/8 air hoses vs a 1/4 mainly because it acts like a bit of reserve with constant use, however 3/8 is heavier, harder to move around (when 50-100’ long) than the 1/4 air hose… I just run 1/4 at my home shop… Now hard lines with drop downs are much bigger…

One advantage to an air impact is if you are working on both sides of the vehicle, you can slide your impact across the floor to the other side and then grab the air hose to pull it back, helps if laying under a vehicle on jack stands etc…