Battery powered impacts have more torque than corded?

[ggielen]

I'm doing a bit of research on impact wrenches, corded, powered, and air. I'm looking to add an impact to my setup and would prefer electric. Air still is king of the hill when it comes to torque, but it requires a solid compressor setup to unleash that power. I was reading recently about pressure drop, and that suggests the average (even toolnut) homeowner setup is lacking in the pressure numbers right at the output (tool), even though compressor specs may seem up to the task, thus rendering part of the air tool capability unused. I don't know what impact (hah) that has on an impact gun's torque exactly though, and i should do some more research.

Anyway, partly because of compressor setup reasons (don't want to drive a costly installation, though i'll get something decent), and partly because of the instant-on convenience of electric, i'm leaning towards electric.

Next question is corded or battery. I love battery powered tools, the convenience and mobility is hard to beat, and ever since 18V li-ion they've come a long way. But in this case i figured, corded has to have more torque right? Torque is good, i want me some more torque, so i looked up the numbers. To my great surprise, i find the opposite of what i expected... battery powered impacts offer significantly more torque than their corded brethren! Here's an example, The Milwaukee 18V fuel appears to be the highest torque battery offering around, so that's my benchmark. It's corded counterpart isn't even playing in the same league, just based on these numbers, i'm not even sure it's playing the same sport:

Milwaukee 18V fuel 1/2"
700 ft-lbs torque
1,100 ft-lbs nutbusting torque
http://www.milwaukeetool.com/power-tools/cordless/2763-22

Milwaukee Corded 1/2" impact wrench (7A motor)
300 ft-lbs torque
Nutbusting torque not listed (not biased left or right?)
http://www.milwaukeetool.com/power-tools/corded/9071-20

Now, there are more powerful corded 1/2" impacts out there, i just kept the comparison to Milwaukee for illustration purposes, and you can go to bigger drive sizes, but on an apples-to-apples same drive size basis, i couldn't find a corded impact that beats the Milwaukee 18V fuel impact.

My real question is, how's this possible? Can you get more torque out of a DC motor than a comparable size AC motor? That's the only thing i can think of, in every other respect the corded options seems to have better numbers backing it up: higher voltage, higher wattage, essentially no amperage draw limitation, so manufacturers could choose to make them more powerful (other than cable AWG and your breaker). I'm an engineer, but my electrical (theory) knowledge is weak, and this observation really puzzled me.

 

[franzdom]

It's not an EE thing, it's a marketing thing, all of the development money is going into battery tools, particularly impacts, much less so into corded impacts.

 

[dnschmidt]

It's a fact. I think development of corded power tools has basically ceased. All effort now is directed to cordless, in Milwaukee's case FUEL brushless technology. No doubt if they put forth the effort to make a 1000 ft-lb corded tool they could do so, there just isn't any market for it. If you need killer power you're going with air tools anyway. That's who the cordless are competing against.

 

[CobraRed]

The eliminating cost by not needing an air set-up makes sense to me, but after 3-4 tools aren't you just buying an expensive lithium battery, charger and electric motor over and over?

 

[rlitman]

The eliminating cost by not needing an air set-up makes sense to me, but after 3-4 tools aren't you just buying an expensive lithium battery, charger and electric motor over and over?

It depends on how many tools he needs. And if a system allows him to share batteries (so only the motor is repeated). The "Bolt-on" system and similar ideas try to get past this, but purpose-built motors generally work out better on these cordless tools.

That, and there is still a big advantage to cordless over pneumatic in that there is no cord/hose. There are advantages and drawbacks to going either way, and for each individual, one choice may make better sense than the other.

 

[bcradio]

Everyone nailed it pretty much. Not much R&D going into corded electric right now... It's all going to cordless.

As for your compressor conundrum, you will get full power out of your impact if you have a decent sized tank... No issues there. Also there is zero install cost for one. You buy one, plug it in to the wall, and plug in your air hose and go. Only cost is an air hose and some fittings. You can do as simple or elaborate install as you like.

 

[scw1991]

I tend to agree with franzdom. It's like buying a 5HP Shop-Vac.......

I have the Milwaukee 9072 corded impact and it buzzes lug nuts off my K1500 truck as fast or faster than my IR231C pneumatic impact coupled to my IR2475-N5 80 gallon 2-stage compressor.

 

[ggielen]

I think you guys are definitely right about the general market shift to battery, and with that the manufacturers R&D $$. But boy is the difference huge with these impacts' performance. Anything that needs some oomph i just instinctively think of corded, my Makita battery angle grinder for example is a joke, barely gets through a nail because it stalls when it draws too much current, whereas my corded Bosch will eat steel for breakfast. With the impacts it's a complete 180 degree different conclusion.

CobraRed, you're right about the motor, you have to buy that every time, but most of the time you can buy the bare tool (no battery and charger) and the battery is were a good chunk of the cash is. And a good compressor setup will still be required for other applications, so i can't totally elimiate that anyway. I guess culturally/growing up i'm just not as used to air powered tools. I grew up in Belgium and now live in the US, and i never really saw air tools used back in Belgium, whereas in the US they're more broadly adopted it seems. I'm generalizing of course as i'm extrapolating my own limited experience. Personally i definitely think of electric first for that very reason, you stick with what you know to a degree, if only simply because you never knew there was a better alternative out there. And i haven't eliminated air impacts by the way, i'm willing to learn new tricks if they prove better than the old ones

 

[redmed]

That's the dilemma I find myself in. I have a air impact that I pull out maybe 2-3 times a year. I will add a pipe to my ratchet first, if that does not work, I fire up the air compressor and pull out the air hose. All that for a few bolts. I'm thinking I might use a corded impact more often, but I'm sure I would use a M18 impact even more. I just can't justify spending the bucks for a M18 impact. I have M18 & M12 hex impacts that I'm going to try using before deciding what to do. Maybe I might find the hex impacts quite useful and just keep pulling out the air impact a few times a year. But there have been times the air impact has worked real hard to loosen something and a couple times it could not budge the bolt without soaking in PBblaster overnight. The torque of a M18 impact is verry tempting.

 

[shanny19]

Milwaukee Corded 1/2" impact wrench (7A motor)
300 ft-lbs torque

I have a corded Dewalt rated at 240 ft/lbs, and it has done everything it's ever been asked to do. (Cars, light trucks, antique tractors, & scrapping).

 

[shampoop]

I don't think it's the lack of development that everyone seems to agree on. I've noticed that corded and cordless electric tools develop their power in very different ways. Corded tools seem to be use very high rpms and not much amperage to develop power. Cordless tools seem to be the opposite, less rpms, but much more amperage and torque. You can very easily hear it when you free spin a corded drill vs free spinning a cordless drill. The corded takes a while to reach max speed but it's max speed is crazy fast, the cordless reaches max speed instantaneously but is not as high of rpm as the corded.

 

[yohn]

Feels like everywhere I look, battery is claiming to be better than pneumatic. We all know that isn’t true, but a Matco pneumatic 1/2 in impact claims 900ft. lbs. of fastening, while the Milwaukee battery powered 1/2 in claims 1000ft. lbs. fastening. There’s no way a battery is stronger on the same drive size right? Or am I just wrong?

 

[tak1313]

I wonder IF someone worked on a uber corded impact, what is the max potential?

TO ME, if it's a seriously high number that could blow cordless away, I would think there would be some kind of good market for it, especially in the pro/industrial sectors.

 

[hogdaddy]

Feels like everywhere I look, battery is claiming to be better than pneumatic. We all know that isn’t true, but a Matco pneumatic 1/2 in impact claims 900ft. lbs. of fastening, while the Milwaukee battery powered 1/2 in claims 1000ft. lbs. fastening. There’s no way a battery is stronger on the same drive size right? Or am I just wrong?

This beast Matco claims 1700# breakaway & 900# install.
Is this the one your referring to?

1/2" DRIVE AIR IMPACT WRENCH - PURPLE MT3779PP | Matco Tools

www.matcotools.com

I just recently bought a Husky 1/2" air impact and it's 800# breakaway and 650# install.

 

[garfunkle24]

Feels like everywhere I look, battery is claiming to be better than pneumatic. We all know that isn’t true,

Do we? Based on what data or evidence?

What's the world coming to? Soon enough some egghead will be telling us electric cars can work as well as IC ones.

 

[WWheeler]

Feels like everywhere I look, battery is claiming to be better than pneumatic. We all know that isn’t true, but a Matco pneumatic 1/2 in impact claims 900ft. lbs. of fastening, while the Milwaukee battery powered 1/2 in claims 1000ft. lbs. fastening. There’s no way a battery is stronger on the same drive size right? Or am I just wrong?

In actual torque testing (not manufacturer claims) the current strongest 1/2" impact, air or cordless, is Dewalt's VTec 20VMax DCF961 that tested at 1015 ftlbs.

Milwaukee's strongest 1/2" dr cordless (at the moment-they and Dewalt have been in a sort of arm's race) is their 2967-20 which tested at 920 ftlbs. Matco's 1/2" dr MCL2012BIW tested @ 894 ftlbs.

As far as 1/2" dr pneumatic's go, the current strongest is Matco's MT3779 which tested at 898 ftlbs.

 

[Leaflessshadetree]

My 1/2" M18 works as well or better than my pneumatics, as long as the nut/bolt comes loose. Not having the hose or compressor can be a huge advantage.

 

[KnurledNut]

It's crazy how far battery tool performance has come in just the decade since this thread was originally dropped in 2014.
Even before then, I remember when Makita first introduced the LXT lithium series. It was night and day difference over its predecessor. We received the very first impacts and drills the local authorized distributor received and those tools were a joy to use professionally. Then brushless motor technology was introduced along with newer battery designs and they have continued advancing ever since.

Getting back to the necro-bump inquiry by @yohn, check out the 3/4 drive Makita XGT. Its quite impressive.

Ultimately, all these impact wrenches are limited to the strength of the drive anvil.

 

[BrandonV]

The market doesn't want corded impacts.

While consumers might be satisfied with a corded impact in their garage, professionals working on construction sites or in remote areas without power drive the demand for battery-powered tools.

I've been watching the construction of a high-rise building, and all I see are millions of dollars of big red tools being used everywhere in areas where running temporary power or a pneumatic line would be impractical.

 

[acer66]

In actual torque testing (not manufacturer claims) the current strongest 1/2" impact, air or cordless, is Dewalt's VTec 20VMax DCF961 that tested at 1015 ftlbs.

Milwaukee's strongest 1/2" dr cordless (at the moment-they and Dewalt have been in a sort of arm's race) is their 2967-20 which tested at 920 ftlbs. Matco's 1/2" dr MCL2012BIW tested @ 894 ftlbs.

As far as 1/2" dr pneumatic's go, the current strongest is Matco's MT3779 which tested at 898 ftlbs.

How strong do they have to be for a home guy or is bigger always better?

 

[vanapplebomb]

I tend to agree with franzdom. It's like buying a 5HP Shop-Vac.......

I have the Milwaukee 9072 corded impact and it buzzes lug nuts off my K1500 truck as fast or faster than my IR231C pneumatic impact coupled to my IR2475-N5 80 gallon 2-stage compressor.

Just to clarify, are comparing air to electric, or new tools vs antiques?

Keep in mind the 231 series is a 40 year old design… It was top dog in its day, but it has only had minor changes along the way. Stronger now than 40 years ago, but doesn’t really keep pace with other modern air impacts.

 

[tiredoldironworker]

Ironworker here. We beat on Milwaukee big dog impacts all day long. Some have rattled up over tens of thousands of 3/4 inch bolts. They ALL outlast their 5 year warranty.

 

[Fedwrench]

Corded impacts are just huge compared to everything else that's available today.

 

[shannonw]

The high torque milwaukee is the version of the lineman 2865-20 i have that (linemen) , and it's a beast and your arm will feal it too. Drives 11/16, 7/8 3/4 augers or whatever thru 10" pilings all day like nothing, cranks off salt water nuts sitting 30 years in cca like nothing, drilling lag bolts ,etc , pulled off a honda crankshaft bolt ziirp done 2 second. i use an impact adapter with it for sockets because i mainly use it for drilling pilings and such. That's said it's heavier and bigger than ****...not something i'd want to use in the garage but i do for the this ain't breaking loose any other way stuff. But when i do use it my noodles clearly tell me....