Dewalt and other Stanley Black & Decker cordless power tool brands use UWO, or unit watts out, as a way to compare the performance potential of cordless drills and drivers.
In a nutshell, the takeaway is supposed to be that a Dewalt cordless drill with a higher UWO rating will perform work, such as a drilling or driving task, faster than another Dewalt cordless drill with a lower UWO rating.
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Let’s say you have a Dewalt cordless drill with 340 UWO rating, and a Craftsman cordless drill with a 280 UWO rating. The Dewalt is going to be more powerful.
UWO is intended to give a fuller picture of a cordless drill’s power or performance potential than torque specs alone.
In North America, Dewalt, Craftsman, Porter Cable, and other Stanley Black & Decker cordless power tool brands generally do not publish the maximum torque specs of their cordless drills and drivers.
Can you convert UWO, or unit watts out, to a maximum torque rating, to allow for easier comparison across multiple brands?
The short answer is that you can’t. What follows is a detailed explanation about how and why UWO simply can’t be converted to a torque rating.
If you’re not in the mood for math, stop here!
UWO, or Unit Watts Out: What Does it Mean?
Unit watts out is a measure of the power output that can be achieved by a cordless power tool’s motor and drive components. It can be considered as a measure of a drill’s ability to perform work, and is a function of torque and speed.
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Torque is a measure of a tool’s ability to produce turning force, and is often used as a way to compare different cordless drills and other power tools with respect to power. However, maximum torque ratings alone can lack context.
Dewalt adapted UWO as a way to combat the misconception that the higher the torque rating, the faster a drill can perform or complete an application.
The issue with this, or at least consumers’ frustrations, is that no other brands use UWO outside of Dewalt and other Stanley Black & Decker power tool brands.
The Math: Power, Torque, and Speed
Let’s talk about the relationship between a cordless power tool’s motor’s power, torque output, and speed.
For the sake of simplicity, we should consider the entire power transmission system as one component. The motor, gearbox, and chuck together are what deliver cordless drill/driver or power tool performance. For ease of explanation and analysis, let’s assume this is all combined together as “the motor.”
For a typical power tool motor:
P is power, in Watts, 
If you want to use in-lbs of torque, you’ll need to add in another step. 1 Nm is equivalent to 8.85 in-lbs. I’ll spare you the details, here’s the Wolfram Alpha conversion if you want to double check. So, if you have torque specs of 885 in-lbs, you’ll need to convert it to 100 Nm.
Since we typically work with motor speeds of RPMs, rotations per minute, we need to do some substituting. The angular speed is in units of radians per second. 1 rotation per second is equivalent to 2π radians per second, so you just plug in 2π for proper conversion.
N is the rotations per minute (RPM). Since we actually need that speed to be in rotations per second, we just divide by 60 (1 min = 60 seconds).
That gives us:
Simplifying for the constants, we get:
If you want to use torque values in inch-pounds, N that equation becomes:
To simplify things:
K is just a constant that depends on the units you’re using. If you want to use foot-lbs of torque, for example, that constant K is what changes. For torque in Nm, K = 0.1047, and for torque in inch-pounds, it’s 0.0118.
Convert UWO to Torque
Okay, so how do you use that equation, 
Let’s say you want to buy a new cordless drill, and its specs say it’s rated at providing a maximum power output of 500 UWO. Another cordless drill that you’re looking at from another brand is rated at 640 in-lbs of max torque. Which cordless drill is more powerful?
Here’s the hard part, and I know some of you are going to get frustrated now. The short answer is that you cannot convert from UWO to torque. It simply doesn’t work that way.
UWO is a measured specification, derived from measured torque and measured speeds.
When you look up a Dewalt or Craftsman cordless drill, its box or product page will usually have a power specification, such as 500 UWO, and speed range specifications, such as 0-450 RPM and 0-2000 RPM.
The maximum torque will be available at lower speeds. But at 450 RPM? That’s hard to say, because those speed ratings are no-load settings, when the drill is allowed to free-spin. Cordless power tools sometimes operate at slightly different speeds under load.
Let’s say you have a Dewalt cordless drill with the following specs:
- 820 UWO
- 95 Nm max torque
- 0-450 RPM lowest speed range
- P = 820 W
- N = unknown
- K = 0.1047
So, solving for N, you have:
N = 82.4 RPM
If you are given the max power of a drill in UWO, and a speed range, such as 0-550/0-2000 RPM, you simply don’t have enough information to determine the maximum torque of that drill.
With this equation, you can calculate the max power output of a cordless drill motor, or any other cordless power tool or DC motor, using measured values of torque and rotational speed. The constant K is only a unit-conversion factor that allows for deviation from Nm and radians/second.
Working Backwards
In the European market, Dewalt and other Stanley Black & Decker brands provide added specifications for their cordless drills:
- Power output in UWO (unit watts out)
- Max soft torque in Nm
- Max hard torque in Nm
- Speed
Hard and Soft Joint Torque
A soft joint is a physical connection where the material between a nut and bolt have low stiffness when compress when tightened. Additional tightening is needed to tighten things up snug.
A hard joint is a physical connection where there is high stiffness in the material between the nut and bolt surfaces. With such a connection, the fastener is tightened snug and then can only be turned a little more before it reaches final torque.
So, let’s say that you’re fastening two steel plates together. The nut and bolt are tightened to snug, and then you reach full torque in less than 1/8 turn. That’s a hard joint.
Now let’s say that you are instead fastening a wood board to a wood stud. Once snug, the fastener needs another full turn or more before it’s at final tightness or torque. That’s a soft joint.
There are different ways of defining hard and soft joint parameters, but we won’t get into that here. A cordless drill or driver will have a higher hard torque rating than a soft torque rating.
Generally, a “hard torque” rating will be its “maximum torque.”
Some Examples
| Dewalt Cordless Drill Specs | |||
|---|---|---|---|
| Model | UWO | Torque (Nm) |
Low Speed (RPM) |
| DCD777 | 340 | 65 | 500 |
| DCD790 | 360 | 60 | 600 |
| DCD791 | 460 | 70 | 550 |
| DCD990 | 650 | 80 | 450 |
| DCD991 | 820 | 95 | 450 |
You can get the torque specs in inch-pounds by multiplying by 8.85 if you’d like. For instance, 60 Nm hard torque is 531 inch-pounds.
| Dewalt Cordless Drill Specs | |||
|---|---|---|---|
| Model | UWO | Torque (in-lbs) |
Low Speed (RPM) |
| DCD777 | 340 | 575 | 500 |
| DCD790 | 360 | 531 | 600 |
| DCD791 | 460 | 620 | 550 |
| DCD990 | 650 | 708 | 450 |
| DCD991 | 820 | 841 | 450 |
Regardless of the units, there’s no patterned correlation between these numbers.
Imagine that the torque isn’t given.
K is 0.1047 when Nm is used, 0.0118 when in-lbs is used. But that’s not important here.
You can use this equation to determine any value, if the other two values are known. Let’s say you know that the DCD791 cordless drill can deliver 460 UWO, and that its max torque is 620 in-lbs. Well, it can give you this max power output at ~63 RPM. But you’re not given that information!
A Broken Equation
A valiant attempt was made by another tool review website to find a way to ballpark-estimate max torque from UWO.
Their equation:
Torque (in-lbs) = MWO x K / Speed (RPM), where K is 560.
Unfortunately, this just doesn’t work.
Using a set of known values for max torque, MWO (maximum watts out), and speed, they saw the ratio to be ~560. However, that ratio isn’t a constant. When looking at multiple data points, such as those shown above, things don’t match up.
Unit watts out is instead calculated using torque and speed measurements. You’re given zero-load speeds in on-paper specs, and there’s no way to use that to calculate torque. You need UWO and speed under load to determine torque.
So for UWO, torque, and speed, you need 2 corresponding values to get the third. In testing, speed and torque can give you UWO. On paper, UWO and speed can give you torque, or UWO and torque can give you speed. You’re never given that speed at which maximum power is achieved, and so you can never calculate max torque.
Can We Find a Pattern?
DCD777 is rated at having 340 UWO, 65 Nm max torque, and 500 RPM for the lower setting.
DCD791 is rated at having 460 UWO, 70 Nm max torque, and 550 RPM for the lower setting.
Both are compact cordless drills. Comparing the two, DCD791 has 35.3% greater UWO, 7.69% more torque, and 10% faster speed at the low speed/high torque setting.
Looking at the different examples in the table above, we can use the UWO and max hard torque specs to calculate the approximate speed at which the torque was measured for the calculation of UWO.
| Looking for a Pattern | |||
|---|---|---|---|
| Model | UWO | Torque (Nm) |
Speed Ratio |
| DCD777 | 340 | 65 | 0.100 |
| DCD790 | 360 | 60 | 0.096 |
| DCD791 | 460 | 70 | 0.114 |
| DCD990 | 650 | 80 | 0.173 |
| DCD991 | 820 | 95 | 0.184 |
Take that speed, N, and divide it by the max speed of the high torque setting, such as 450 RPM, to get a ratio.
Potentially, we *could* take an average and come up with a category estimate, say 10% for compact drills, and 18% for heavy duty.
The first three model numbers are compact cordless drills with 2 speed ranges, and the other two are heavy-duty 3-speed models. All of these models are brushless drills, by the way. The more different drills have in common, the more reliable, or rather less unreliable, any conclusions can be.
So, let’s say we now have an unknown, such as the Dewalt Atomic series DCD708 cordless drill. The Dewalt Atomic DCD708 is rated at 340 UWO, with a lower speed range of 0-450 RPM. With 340 UWO and 450 RPM, and guessing that its max torque is at 10% of its speed, we can calculate a ballpark torque of 72Nm. However, I dug up a Czech product catalog, where they say that the DCD708 has a max torque of 65 Nm, just like the DCD777.
Looking at those two models,
DCD777: 340 UWO, 65 Nm max torque, and 500 RPM for the lower setting.
DCD708: 340 UWO, 65 Nm max torque, and 450 RPM for the lower setting.
There’s no high-confidence pattern, but I’m open to being wrong. If you play with these or other drills, and can find a pattern which can be used for a simplified UWO to torque conversion equation, please let us know!
However, there’s also the fact that UWO is a measure of a cordless drill system’s performance, including the motor, gearing, chuck – the power transmission from motor to accessory mount. Different motors and gearboxes will challenge any patterns that might appear.
Maybe this pattern can still be used for rough calculations? I reviewed a Craftsman compact cordless drill a few months ago. It’s a brushed motor drill not brushless. It’s rated at 280 UWO and 0-350/0-1500 RPM. Using the pattern from above, let’s assume that the maximum torque is achieved at 10% of the low-speed max, or 35 RPM.
So, 280 UWO divided by (35 * 0.0118) = 678 in-lbs max torque? That’s definitely not right. Based on performance, I’d guestimate that the maximum torque is under 300 in-lbs, since this drill seemed to lack power compared to the Skil 12V brushless model. If true, this would mean that the max torque is achievable at around 80 RPM, which would be nearly 23% of the max speed at the high torque mode.
Additionally, there is no guarantee that UWO is calculated at the time of max torque. UWO could be at an intermediate speed, corresponding to an intermediate torque.
Dewalt now describes UWO on their website as:
The point where the drill’s speed and torque output are the highest.
That point might not be at the maximum torque point in a speed vs. torque chart. We can make assumptions, simplifications, and generalizations based on trends and perceived patterns, but there’s no way to validate any of them, unless you either work for Dewalt or Stanley Black & Decker, or have a dynamometer, a very expensive piece of equipment used to measure motor torque, speed, and power.
So What’s the Point of UWO?
A cordless drill or driver’s max torque tells you about its maximum torque at 0 RPM.
More than 10 years ago, when UWO came out, Dewalt explained that UWO was a more accurate portrayal of a cordless drill’s performance. Indeed, looking at UWO is a great way to compare different cordless drills in Dewalt’s product family. It’s a measured value that is dependent on speed and torque combined.
One drill is rated at 400 in-lbs max and with 0-400/0-1500 RPM speed settings, and another at 380 in-lbs max torque, with 0-550/0-2000 RPM speed settings. Which is the more powerful tool?
With UWO, you can look at different values and see how different tools compare against each other. It’s intended as a measure of performance and application speeds, rather than simply being a zero-RPM torque measurement.
Unfortunately, as helpful as it might be, there’s no quick, easy, or confident way to convert a UWO value into max torque specs.
If you want to know the max torque of a specific cordless drill, your best bet is to look at Dewalt’s UK website, or overseas retailers’ product pages, where soft and hard torque values are often published alongside UWO.
If you want to know the max torque of other Stanley Black & Decker brands’ cordless drills, such as Craftsman or Porter Cable, you might simply be out of luck.
You can’t draw parallels between different models either. Two drills might both be rated at similar UWO ratings, but one could potentially deliver higher torque and lower speeds, or lower torque at higher speeds.
Dewalt intended for UWO to be a new standard by which cordless drills could be better compared against each other. However, no other power tool brands outside of Stanley Black & Decker are using it yet. Given the amount of time that has passed, other brands might never adopt UWO as a measure of cordless drill or power tool performance, at least not in marketing materials.
To summarize everything, UWO is a marketing convention that can be used for comparing cordless drills and drivers by Dewalt, Craftsman, Porter Cable, and other Stanley Black & Decker brands. Unfortunately, there’s no easy way to use that UWO when comparing SBD brands’ drills with other brands’, such as by Milwaukee, Makita, Bosch, Metabo, Ridgid, Ryobi, or any of the power tool brands that typically publish max torque specs.
But, hopefully at least this discussion helps you better understand what UWO is and what it means.
I am definitely open to different opinions. If you know of an accurate and consistent way to determine maximum torque from UWO and no-load speed specs, please let us know!
Also, I took all reasonable efforts to check, double-check, and triple-check all my math, assumptions, simplifications, and conclusions. Please let me know if you find anything that doesn’t add up, make sense, or hold true.
Chris
Just buy the drill with the highest UWO. That’s how I solved the problem
Stuart
And how does it compare power-wise with the latest Milwaukee M18 Fuel and Makita models? That’s the issue a lot of people face when doing their purchasing decision research.
Chris
Well, I already had the Dewalt 20v max system. Soooo, I guess that doesn’t help others looking for a cordless platform.
Hrmm.
lou
May I have your opinion on the 20v max system??
Carlos Bertolli de Gouveia
Comparar com o que? Só pode fazer isto dentro da mesma marca.
Chris
In all UWO is a better measurement of power then peak torque IMO because I think most brands overstate their torque numbers
Stuart
Agreed. But I don’t see other brands jumping on the bandwagon.
I have heard opinions that Dewalt developed the standard because their torque specs weren’t working in their favor.
Based on the very many questions I’ve been asked over the years, I’d say that UWO is almost as confusing as 18V vs. 20V Max.
Thom
And because I can’t readily compare Dewalt with other companies products I just don’t buy yellow anymore.
OldDominionDIYer
Bingo! That was my conclusion as well…
Trevor Colin
DeWalt’s own claims is getting destroyed by private torque testers, where these tools are over exceeding- by A LOT.
THE TORQUE TEST CHANNEL on YouTube puts them all on his fancy dyno.
The 900 is doing like 1600 lbs-ft of torque
The 891 600 and 800 in reverse.
They are killing it in everything!
The real answer is whatever batteries you’re invested in. But DeWalt has been great with warranty as well’ Milwaukee is kind of stuck with their 18V batteries
Drew M
I can say with confidence that Bosch overstates their torque, Milwaukee is about right and Makita understates their torque.
If Dewalt was serious about “UWO” then they would publish a testing specification and method for their competitors or an independent lab to test and verify their numbers. IMHO, UWO is just a dumb number that some marketing person is having printed on the box. I’m honestly surprised they don’t add a few zeros to it, to make it sound more impressive.
Chris
Yeah. UWO means nothing if other drill brands don’t use it.
Aaron
Agreed. Publish the test spec. That’ll be the easiest way for it to be adopted
Adam Sperry
They won’t publish that test spec any sooner than anyone else will publish theirs. Marketing on power tools is a self serving distraction at best. The only way to tell is to buy whatever you’re looking at or trust someone who already has. I trust them all as much as I trust my 6 year old alone in the kitchen.
Jim Felt
Wouldn’t it be a hoot if Consumer Reports weighed in on some of the better brands? But wouldn’t they too would need to measure them all by some (maybe new to the industry?) consistent means?
We know Taunton Press has tried for decades in their Fine Homebuilding/Fine Woodworking Tool Reviews. .
But they cherry pick similar style tools, I imagine, simply because there are way too many darn tool models and brands to do more.
And they tend to shy away from dealing with manufacturer’s claims of “power”.
AKA we’re all slightly in the dark.
But here again Stuart is putting in s whole lot of research and effort to help us all as tool consumers. Thanks, man!
William McGrath
Thank you for such an in depth explanation!
Stuart
Thank you! I was worried that I over-did it.
Chris
I found myself skimming the math looking for a conclusion. It was easy for me to make the assumption your math was right after the first few paragraphs.
I found myself wondering if the post was needlessly detailed, but then determined if you would not had had the details there would have been many questions sent your way about how xyz worked.
In the end I appreciate the effort and believe it was a good compromise between detail and brevity.
Aaron
As an engineer I love all the math. It helps explain the difficulty in comparing models. It would be nice if there was some asme standard test.
Thanks for urging this together!!
J
Yup. Great info. Its kinda nice to know i wasnt just me.
Unfortunately i fo have the dewalt set-
John
More BS from Stanley Black & Decker. Buyers are suckers with bright yellow and red. In the end, the point of tools is to perform work by building or repairing things. The more you build or repair the more you realize how much crap marketing means nothing and you stop paying attention. I build for clients and they don’t care what tools I use, just how good the end results are for the price paid. I wish people would spend as much time building better quality in their daily work than reading, comparing and debating specs.
fred
Amen. When we were considering buying a new tool – we took the advertising hype and printed specs with a grain of salt. I can’t remember having any of the crews tell me that a new drill (as an example) had dramatically improved their craftsmanship. I might have heard that they liked or did not like some new feature of a new tool – maybe thought it could make them more productive or safer – and that could be a reason for phasing it into our tool inventory. There is however, a cult that seems to demand having the newest, most powerful, shiniest or whatever else we might use for comparison. If that makes the tool buyer/user feel good – I guess that’s OK. But tools are a means to an end and having the newest and best is good but it is not a substitute for having the skills, knowledge, training and talent to use them.
Meanwhile. let’s thank Stuart and Toolguyd for continue to educate us and help us sort through tool “specs” so we can make better informed buying decisions.
lou
Hello! some recommendations for hammer drill or driver drill, average use?
Thanks in advance.
Corey Moore
Damn lol I dug that up from when I went hunting awhile ago, and seems I ended up perpetuating false information. Sorry, Stu and those I replied to!
Stuart
Not your fault, or theirs. Well, maybe theirs for not verifying the math, but it was a good attempt with good intent. I started questioning the “constant,” because the last time I tried to find a conversion factor it fell flat, and that took me down a long journey today to see if I could settle things for good.
A W
Thank for setting the record straight.
It makes sense that UWO as a measurement of peak power would not have a direct conversion to torque at zero RPM.
HTG
Just one nit to pick, Stuart. You said, “1 radian per second is equivalent to 2 x pi rotations per second.”
I think you mean, “1 rotation per second is equivalent to 2 x pi radians per second.”
Sadly, that’s what a PhD in physics has for me!
A different question- is UWO a more useful way to compare with corded tools? This side of the pond, we do that in watts, while you tend to count amps, I think. But watts and amps are more predictably related. So you only have to assume an efficiency.
Stuart
Thanks! *Fixed*
I agree, UWO would indeed seem to allow for fair, or at least reasonably fair comparison between corded and cordless power tools. But UWO specs seem to be limited to cordless drills.
CountyCork
What’s the most reliable method to measure torque. Do all brands measure torque using the same method? If not it’s all kind of meaningless to compare torque between brands anyway.
taras
Skidmore Wilhelm makes torque/bolt testing rigs. They are a benchmark standard for testing torque tools and bolts. The simplest way to test torque output would be to measure bolt tension. Set up a rig where a nut gets tightened onto a fixed bolt/stud, and tighten the nut. Then use an extensometer (an ultrasonic tension measuring device) to record the tension value in the bolt. It’s more accurate than typical torque measurements.
Faux Slim Shady
You can’t reliably use that as a means to measure torque as the bolts themselves are variable in the amount of torque they can handle being applied to them, lol.
To remove variables you have to remove production made inconsitencies and many companies specializing in measurement devices go to extremely long lengths to do just that, having ideal setup testing conditions as well as zeroing out procedures just to account for the variances in their OWN measuring devices.
Simplest methodology will produce the most variable testing results. Might as well try to test bolt torque in field applications by using springs as it will give similar, all over the place, readings.
Tests need to remove screw(/aka bolt) induced variations, so a non threaded rod far exceding the strength requirements needed to test for typical load applications coupled with a means to load the rod with resistence and a means to accurately and precisely measure everything through the startup to stopping phases of work aplication.
ie, use another drill rewired to produce quantitative and qualitative output mesurable across all other drill testing, then procedurally zeroed out throughout the testing phases.
Doug
Great article, Stuart. Good, clear, technical writing. Lots of work for you I bet, but well worth the effort.
The What?
There’s a very good and simple reason that Dewalt and sbd use uwo specs to rate their tools. And I’m surprised nobody has picked up on it this whole time they’ve been printing specs on the packaging. First of all the methods they use to get these specs are done in a lab or in an environment that ain’t got shit to do with real world applications. There’s an infinite number of variables that have an effect on the torque output of a drill or driver that it’s impossible to give a definitive single number. Especially when rust enters the equation. And last time I checked, there’s no dry or head snapping torque rating on a box of bolts or screws. Just like there’s no torque rating on a piece of steel for a drill bit to put a hole through it. Any situation that involves tightening a fastener to spec is done with a wrench and a spec sheet or a manual listing specs. The applications in which people use a drill/driver doesn’t require fasteners being fastened to spec. So if you’re one of those individuals that thinks that the specs are realistic, then shame on you. Sbd obviously figured out a long time ago and this is why they use UWO. Anybody that claims their impact or drill has numerical torque rating is full of shit. Sbd is smart for using uwo. Everybody else should follow suit or just do away with it.
Stuart
Max torque ratings for drills and drivers are also resultant from lab testing.
A lot of fasteners DO often have suggested or recommend torque specifications. For example, check out the last page of: http://www.kerrlakeside.com/wp-content/uploads/page01-11inchsocketheadcapscrews.pdf
But torque and UWO ratings aren’t so that fasteners can be tightened to spec – that would be completely unrealistic. Cordless drills can produce repeatable torque in a qualitative sense, where fasteners can be driven in to the same depth in the same material for a given adjustable clutch setting.
Max torque and UWO gives some context as to the power and performance of a cordless drill. The more powerful a drill and the higher its torque delivery potential, the easier and faster it will perform with larger and more demanding accessories. A 460 UWO drill will be much more capable with a 3/4″ spade bit than a 280 UWO drill, and the same is usually true for a drill rated at say 600 in-lbs than one rated at 300 in-lbs.
Marc
In case someone interested hd has de dewalt dcd460t1 on clearance for 280 (399)apparently is no going to be sold at the store anymore
Koko The Talking Ape
Well, electric motors tend to have constant torque, regardless of how fast the motor is turning. That is why even weaker electric cars can smoke their tires.
Given that, it seems like torque would be a resonable way to compare or rate electric motors, and thus drill/drivers. It leaves out terms that don’t matter.
Dewalt’s “Unit Watts Out” or really just “watts” (or “horsepower”) or really just “power,” lets you correct for differing torque at differing speeds. So a DW drill could, for instance, put out a huge amount of torque when the drill isn’t turning at all, and that would have the same UWO as a drill putting out a small amount of torque when spinning at high speed. The thing is, we don’t care about the torque at zero RPMs, because then it isn’t doing any useful work. And as I said, electric motors tend to have constant torque anyway.
So why not just use torque?
I think a testing facility could just measure and publish the torque of DeWalt tools (maybe at a few different operating speeds, just to be fair), and ignore their UWO measurement.
Aaron
That makes sense. Plus it seems the drills are powerful enough. Certainly as a diy it is plenty powerful for my needs.
Nick
Electric motors certainly do not have constant torque over the speed range. They have their highest torque at the low end and it tapers down as the speed increases.
Electric cars can smoke their tires specifically because they have all of that torque at the low end of the speed curve. That excess of torque helps them overcome static friction a lot better and the dynamic friction is a lot lower now that it’s spinning, hence why they can smoke their tires.
Koko The Talking Ape
You are right; I was mistaken.
But torque appears to have a linear relationship with RPMs, meaning you can take just two measurements and get a good idea of the tool’s torque curve.
http://lancet.mit.edu/motors/motors3.html
In any case, it doesn’t appear that measuring these tools meaningfully is a complex task.
Stuart
It can be linear, but that’s not always the case.
According to that, maximum power is going to be at the point where torque = 0.5 max torque, and speed = 0.5 max no-load speed.
However, this doesn’t work if we try to work backwards from known specs for the aforementioned Dewalt models.
For instance, DCD791 is rated at 460 UWO, 620 in-lbs (converted from Nm), 550 RPM at the high torque, low speed setting.
If we take torque as an unknown, and calculate 0.5 max torque using 0.5 of max speed, we get 283 in-lbs for max torque. But, that’s not the max 0 RPM stall torque that is often given as the hard/max torque limit.
Also, keep in mind that generalizations that might work for motors might not keep true for power tool motor assemblies and transmissions.
With the data available, we can roughly extrapolate the highest speed we can expect to correlate with the highest torque. From there, I’d guess that lower speeds don’t result in any higher torque. That could be why Dewalt sought to promote the UWO standard, because a torque rating at 0 RPM might have been under-reporting the power of their drills compared to other tools that might be similarly rated at 0 RPM but with greater torque drop-up as RPMs increased.
Still, while we can extrapolate some numbers that *could* hold true, there’s not much we can do to understand what we might see at other speeds, at least not without knowing the exact shape of the respective speed vs. torque curve.
TonyT
Correct. Specifying motors is part of my job, so I’ve looked at quite a few torque curves, primarily for small (<400W) servo and stepper motors.
It really depends on the motor type, drive circuitry, etc. Stepper motor torque is great at low speeds, but drops off quickly. Typical brush less DC servo motor torque curves are flat until a certain speed, and then slope down. I haven't looked at enough AC induction motors, and you can have added complications like peak torque (available for a few seconds for most servo motors), field weakening (AC induction motors), and more.
Stuart
The problem with getting independent measurements and specs is that the equipment starts at around $10K and up. And when you take into account how powerful modern cordless drills have become, the cost and complexity climb steeply upwards from there. The equipment is no problem for a company like Dewalt, but there’s not much of a market for 3rd party testing.
Koko The Talking Ape
Hm. Well, then I might think about improvising a very low-precision testing setup. All you need is a repeatable load, such as a paddle wheel buried in water, or just spinning in air. It would need to be calibrated, but that could be done a few different ways; one way might simply to attach a 1 kg weight to a 1 meter arm held parallel to the floor, letting that torque spin the shaft, and videotaping it to see how the rotational speed changes. Taking the derivative of the acceleration would provide instantateous rotational velocity, no?
Stuart
A non-contact tachometer can provide RPM readings.
The problem is in having an improvised setup calibrated and well characterized.
There are smaller and less expensive dynamometers out there, but they can’t handle anywhere near the torque even a compact cordless drill can output.
Promit
And so we get “guy on Youtube drills 400 holes into a 4×4 and tells us what he thinks” instead. I don’t love it.
Ryan Baiad
When I was reading through all this I was thinking in the back of my mind that this measurement seems to be similar to the way car manufacturers list the specs of their engines in horsepower and torque. Glad someone else noticed that too!
glenn
Frankly, the advertised numbers mean nothing. They are simply just numbers. If the tool does the job, then its good enough.
Stuart
If you’re shopping for a new cordless drill, how do you compare models without some quantitative basis for comparison?
Seth
One already can’t compare models with a quantitative basis because the comparison doesn’t work with SBD vs everyone else. I’m guessing only the least informed consumers are shopping SBD vs SBD, since the entire marketing strategy in the industry is tiered into consumer/pro/industrial levels and SBD is attempting to capture all of that with their branding. The consumers can’t compare Craftsman vs Rigid or anyone else and the pros can’t compare Dewalt vs Milwaukee or Makita.
Stuart
You can at least compare non-SBD to non-SBD offerings, and SBD brands’ drills to each other. SBD does publish torque specs for their cordless drills marketed in Europe, and so at least some cross-brand comparisons are possible.
Consumers need on-paper specs for comparison purposes, which is why there’s so much interest in deciphering UWO. Unfortunately, there’s no direct conversion possible by which UWO can provide torque specs for comparison purposes.
taras
You can’t necessarily accurately compare SBD-SBD because when it comes to UWO ratings, those ratings may be skewed depending on where that measurement was taken. In theory, on model may have lots of torque output at low RPM in a very narrow band (a short and abrupt torque curve), but another may have a lower peak value, but have a flatter torque curve, giving you more power over a larger RPM range.
Peter
Easy, try them out. All the manufacturers and/or stores have 30-90 day returns. Algebraic formulas will never compare to spending 30 seconds holding the tool in your hand and using it on real wood/metal. And even if the numbers had useful meaning, which I do not believe, much of the buying decision is subjective and that’s fine. Subjective does not mean frivolous. How does the tool feel in YOUR hands? How does the tool fit in with YOUR work style. Do you enjoy holding and using it? Yes, enjoy. Our tools are extensions of ourselves. Work is hard enough without being stuck with a “highly rated” tool we loathe. I love Bosch cordless while my friends love Makita or Milwaukee. We never debate tools. The proof is in the pudding-the quality of our work.
Stuart
There’s a limit as to how that can be done.
If you order online, you often have to pay return shipping for a product you return for subjective reasons. “I don’t like it” is a valid reason for return, but it’ll cost you.
And if you’re talking about pricier tools, that’s several hundred dollars added to your credit card bill. If it takes you a week to receive and then test a few models, a week for the product to be returned, and a week or longer until the refund is processed, you might end up with a larger credit card balance for longer than anticipated.
One of the things that led to ToolGuyd was my exploration of different options when I was building up my toolbox. Steel-handle hammer vs. wood? 12 oz ball pein vs. 16 oz? Brand A of Phillips screwdriver vs. brand B. Trying different things is time-consuming.
In a perfect world, yes, everything would be available for hands-on demonstrations and testing prior to purchasing commitment, but that’s simply not possible.
ToolGuyd’s goal with reviews isn’t to tell readers what to buy, but to provide a lot of the information that’s not available on the front of a box, or in an online product listing.
However, when researching purchasing decisions, everyone has to start somewhere. With a lot of different products, it starts with specs and ratings of some kind. How much torque? How many megapixels? How much range? How quiet? How much weight capacity?
These values are a way to quickly filter out the better-suiting options from a pool of too many choices.
Blythe
That’s why if I need to do a real life evaluation I buy tools in store. I realize that many specialty tools aren’t available this way, but for the drills and other standard tools we are comparing here buy and return is a viable comparison strategy. If they offer a satisfaction policy then I have no problem taking advantage of it. If it’s a tool that I will have to use regularly for years to come then I need to do my own testing in hand. Sites like yours definitely help to narrow down the choices to the ones I actually buy and try out
glenn
I stand by my comment as I can assure you from actual use that one particular brands 12v drill that claims 30nm is less powerful in real use than another brands version that claims the same torque .And this is having used them back to back.
Stuart
I don’t doubt that. But that’s not going to be universally true.
I personally treat torque specs as a way to generally characterize a drill. Is it a compact drill? Mid-range? Budget? Heavy duty?
It would be fair to anticipate some “fudge factor.” 10%? 15%?
But if one drill from a top brand is spec’ed at say 500 in-lbs, and another at 400 in-lbs, that 500 in-lbs model is generally more powerful. If the speeds are wildly different, that could be a red flag.
If one drill is spec’ed at 300 in-lbs, and has 0-350/0-1500 RPM speed settings, and another is spec’ed at 290 in-lbs and has 0-550/0-1800 RPM, I’d think that second model is more powerful. The first would have some speed sacrificed for higher torque, which to me would suggest a lower performance motor overall.
Specs give consumers a place to start.
aj
A great article but still all confusion. UWO is more useful than other brands, but since they’re the only one doing it people don’t like it.
Publishing an actual torque curve, or even just a point along the curve, such as torque when loaded down to half the rated RPM, would also be more useful.
Rman
Wow I asked if there was a way and you delivered a math equation that took me back to college. Nice write up but way too involved for joe public to convert and then compare
Surely a DeWalt marketing scam
Dave
None of any of that matters. I admire the work that took to research and write, but all I care about is which drill will bore the fastest, largest, deepest hole, or which impact will set the largest lag in hard wood.
Theory never built anything; always remember it’s a results-oriented world.
Still an impressive effort even if all for naught.
Line ‘em up, start drilling and driving. Best results = winner..
Companies all lie anyway so who cares about ANYONE’S claimed numbers? Certainly not anyone who gets something done while the pencil-pushers aren’t.
JoeM
In my personal experience… I think SBD stopped caring about comparing specs with other brands, and put together a more honest spec on their tools just to avoid lawsuits.
Think about it. All brands’ power tools are built in factories, tested in labs, and put out to the public with the specs of the TESTED Model printed on the box/manual/etc. Now, let’s say, for a moment, that the people who are using these tools are not stupid (AKA Reality.) and let’s also say that they have expectations for their tools. If they are using their tool, and something drastic happens, like it can’t get a single hole drilled in X or Y conditions… They’re going to look at the specs, look up the equations that apply to the amount of work those specs would have on the material they’re working with… and see the numbers don’t even remotely match.
Now. Is a spec on a box a guarantee that, in all the steps the machines took to manufacture that product, the end product is guaranteed to perform as if it is in the lab at all times? Reality says no. We, as people who live in Reality, and are not stupid, would therefore never hold a company to those specs in real world conditions anyways. So… Why print them at all? In the case of first-time buyers, trying to maximize their money’s worth in spec values, they may well lack our collective experience when it comes to the variations that come from real-world use. And in THESE cases, I believe the modern tendency for litigation against companies for false advertizing becomes an annoyance that none of these manufacturers want to be bothered with.
What if SBD got too big to bother with this? UWO being so much more difficult to quantify as a performance rating in the real world settings, doesn’t this sound more like an admission that the number is just a rating of what the Model tested at in the Lab only? So that, if anyone punches in enough of the numbers, the + or – 10% difference between the various global conditions the tool is in, end up getting rid of all these frivolous lawsuits? And, ultimately, just pays attention to what the SBD brands compare to themselves?
The What?
Everything that they print and advertise as specs is designed for the one purpose and that is to lure you into buying their products. It’s an advertising gimmick that is intended to give you the impression that you are buying this awesome super powerful tool. When in reality it’s not all that and a bag of chips. This is why they print inch lbs and not foot lbs on the packaging along with rpm, ipm, and so on and so on. None of which has anything to do with what matters to the intended use of the tool. Inch lbs make for a much higher number therefore it gives the impression that it’s super powerful. In reality Inch lbs are very seldom used to spec a fastener. I’ve been doing my own mechanic work for a long time and I don’t recall ever tightening a bolt to inch lbs. Everything is done in foot lbs. If you really want to find out how much torque a drill/driver has then get a torque wrench hold it with a vise and put a torx socket on it tighten your drill chuck on it. Set the wrench to the correct foot lb value and squeeze the trigger. You may have to adjust it several times in order to dial in the exact amount. Remember 12 inch lbs =1 ft lb. When it clicks that’s your torque. You’ll be surprised by what you get compared to what they print. 1200 inch lbs looks a lot better than 100 ft lbs when printed on the box. But in reality 100 ft lbs is the number that counts.
Stuart
It’s a matter of perspective.
Infants aren’t aged as 0.1 years, 0.33 years, 1.2 years. It’s 6 months, 12 months, 18 months. After ~2, their age in years is more conventional to use.m
inch-pounds allows for greater resolution if you will.
4V-class cordless screwdrivers often deliver ~40 in-lbs of torque. That’s a number that allows for proper matching to certain applications. 3.33 ft-lbs?
in-lbs is the convention for cordless drill/drivers and impact drivers. Impact wrenches often have ft-lbs specs.
I get it that you’re more used to ft-lbs. But that doesn’t mean that inch-pounds is a bogus advertising trick. $19.99 vs. $20.00? That’s a marketing trick. Inch-pounds instead of ft-lbs? I’ve never heard anyone complain about inch-lbs being deceptive, gimmicky, or otherwise related to marketing.
You can’t just attach a torque wrench to a drill and compare what you get to on-paper specs. You need a hard-joint coupler and a properly calibrated torque meter, and you take the measurement as RPMs approach zero.
If you were complaining about the max torque not being that useful a specification, you’d have a point. But the units? C’mon. You can’t say that ft-lbs is the number that counts, because it’s the same thing. 1200 in-lbs, 100 ft-lbs. One dozen, twelve, same thing. Is it wrong to market a package of 12 bagels vs. 1 dozen bagels? 20 ounces vs. 1.25 pounds?
The Dewalt mower has a 20″ deck but 19″ cutting capacity. https://toolguyd.com/review-dewalt-cordless-mower-2x20v/ When Ben measured gas mowers, the advertised sizing corresponded to the blade length. So why are cordless mowers advertised by their “deck size” rather than their blade length and cutting capacity?
There are many hidden marketing tactics in the tool industry, but inch-pounds isn’t one of them.
fred
Much of the rest of the world would laugh at this Tow-may – tow/Tow-mah-tow discussion – and probably agree with the Gershwins – i.e.: “lets call the whole thing off”. I can’t get worked up over the manufacturer’s using inch-pounds versus foot-pounds – might have a problem if they started spec’ing things in inch-ounces – but sometimes agree with our metric brethren that newton-meters might make better sense.
Grady
HUH!?
That’s what happens when you mix engineering and marketing!
Same thing happened years ago when the engineering/manufacturing firm I worked for promoted the VP of sales to VP of engineering. Both engineering and sales went down, way down. All because the sales person sold the owner a bag of cow chips.
aj
At least SBD is publishing power, unlike anyone else.
It’s like thinking car is impressive with 250 ft-lbs of torque and a 10,000 RPM redline, only to realize it’s a 150 HP Nissan Leaf.
OldDominionDIYer
Nice article Stuart but in the end it only serves to demonstrate that the marketing decision by SB&D to use UWO has no real world usefulness just as perhaps the lab testing results of torque has little usefulness in the real world. What the use of UWO does do is definitively prevent the consumer from being able to compare like measurements thus possibly creating a certain amount of doubt about what SB&D is hiding behind with their singularly unique measurement method which cannot be reasonably converted for useful comparison. I think Dewalt makes some really good tools but their marketing department isn’t doing them any favors… I know it won’t happen but an industry wide standard with independent testing would resolve this issue once and for all.
Michael
A simple graph showing power and torque at different speeds would make comparison easy and accurate.
Nathan
WOW – great article and try Stuart. It’s why I like this site.
ANd there are some great comments in here pointing the other issues.
The biggest one isn’t marketing, it isn’t UWO it’s the lack of a clear standard point.
Read that again. For the people that bash on SBD’s use of UWO – what’s the stall torque of a milwaukee fuel ______ driver. Is it the listed 1200 in lbs or _____. At what RPM was the 1200 measured with.
As someone else pointed out motors don’t have a constant torque to RPM – as power curve. It’s far worse with brushless motors which can vary per design as needed. It’s one of the reasons you now have such control over inputs like a special setting for running down self tapping sheet metal screws – on a drill that will also run a 6 inch hole saw into 3/4 ply.
So you know – there is a standard testing model – use for engines for decades. These motors (motor gearbox assemblies – whatever) are run on a dynamometer anyway. So post up the chart. OH nobody wants to see that.
Golly I bet many of you did when you bought your last vehicle right? It’s the same physics.
TO SBD’s point they only do this with drills but the same thing applies to so many other tools. Circular saws – golly what torque does it make when running at 5100 RPM? Gee I don’t know but it sure slows down when my 60 tooth blades hits that 3/4 ply birch. It cuts it though, mostly.
Impact drivers – X inch lbs. ANd Z impacts per minute. K – what’s the stall torque. OH right that wouldn’t matter would it. Does it really apply 1800 inch lbs on a bolt – in wood.
Do you see where I’m going here – and the same motors used in the drills are often used in the other tools with different gears.
Some of the best testing – as is done on this site too – is practical example. This drill punched ________ holes in this 4×4 using a 1/2 inch drill bit of ______ make. This other drilled punched in ______ holes . . .. . . using the same bit. Both using their respective compact batteries. . . . . . . .
WOuldn’t matter that the binford 3/4 HP hammer drill with 4 gears and reverse has so much more power than the HitachiCocao driver drill. Because the Hitachi Cocao put in 16 more holes in the test because the motor was that much more efficient.
Then it might be other features you need in a drill – like you can carry it without a support crane. It’s battery doesn’t dim the lights when it charges. It comes in pink, who knows. but feature sets help.
I’d really like drills to bring back the level via or have a flat – square spot on the top so you can ride it against a square. I mean I could use the hell out of that. I do it now but it’s not easy peasy.
Anyway – great read. OH and I agree that if I had to pick I’d prefer UWO – but I want to see it applied universally. Won’ t every happen. Just like in audio systems while standardized a bit. How can 60Wrms/channel fill a room with sound better than 200 Wrms per channel? Or you know pick whatever market.
Steve the Gullible
Thank you Stuart for the great article. I think John hit the nail when he said the customer doesn’t care about the tool, they care about the quality you produce. Yellow, red, blue, green, or pink have almost no bearing on how well you us it. I live across the street from an 1871 flour mill all built with hand tools and craftsmanship. My work is not craftsmanship and I’ll die DeWalt max 20 because I have a bunch and I like them. Logic be damned.
Farid
Sorry, but this is just more marketing BS, trying to look legit to the eyes of customers but at the same time making it impossible to compare across brands. It might as well be a label saying good, better, best or a color coded label, etc.
Just ask the Dewalt engineers what they look for when they shop for motors: the answer will most likely be a torque- speed graph. This how any decent motor is specified, whether electric or gas. Tool companies can easily produce a graph for each tool model they produce and it would make it easy to compare across brands – perhaps so easy that it will reveal the BS too much.
One other note, it is a bit irritating to see torque specified in in-lbs or ft-lb. I know it is a colloquial expression, but it is really lb-ft. The other way is a unit for moments.
bobad
The only way I would trust UWO would be measured at the chuck. There’s just too many ways to lose or gain efficiency in the drive train to use UWO as a standard. Similar to a car, which you measure real HP (or watts) at the rear wheels, not at the crankshaft. Until something better comes along, I’ll trust torque.
UWO should give you an idea how long your battery should last, but it’s just a rough comparison.
Stuart
I can’t imagine that they would test things any other way than as a tool assembly.
ChrisP
I think Dewalt are trying to make the point the max torque is not a reliable indicator of real world performance. If you look at the 991/996 max torque is way below the claimed ratings of Dewalts main competitors (Milwaukee, Makita, Hitachi) yet that drill is as good if not better than any of them.
HTG
I think that the choice of tool is much more complicated than we are giving Stuart credit for here. If there were a single specification which could tell us which is the best tool for us to use/buy, then we would just buy that tool. But we don’t, and that’s because it’s complicated. We are influenced by price, brand, battery system, previous experience with stores or manufacturers, friends, colleagues, co-workers, adverts, the press, internet blogs, and many more. Even if we do get specific about something – we decide we need a tool that weighs less than X, or is more powerful than Y, or shorter than Z – we can still make a short list of tools that meets the needs, and then we choose based on all the other more subjective things.
You see fundamentally, human beings are not rational. No-one has ever actually needed a sports car, for example. Yet I have one. It’s not the most economical, it’s not even the fastest. It’s definitely not the most reliable. But it’s the one I wanted. Cars are a good example. People have mentioned how cars often are specced with torque curves. But I don’t believe anyone would choose between, for example, a Lamborghini and a Ferrari based only on the torque curve. So many other things influence us. Which is the tool we will get the most satisfaction out of using? That’s a really important question for me.
So is UWO or power a better discriminator? Probably each is better is some situations. I do find it frustrating that they can’t be compared across brands. Slightly. But this is at the root of why what Stuart does here is so valuable. Choosing the right tool is hard. Help from people like Stuart is valuable to us, and that’s why we read here, and probably other tool-related websites as well.
Personally, I do use the specs to choose cordless tools, but like this. I am bought into M12 and M18. I have one DeWalt 8V max tool. Typically, I will look only at tools on one of these platforms. I’ll use the specs to find the right point in the extensive range (at least of red tools) for the task in hand. Sometimes, I’ll use the specs to weigh up whether it’s worth the cost increment for the next model up. And that works well enough. So the specs do help.
A while ago, I did jump platforms. I had a range of perfectly good yellow tools, and a set of old, broken NiCd batteries (remember them?). It wasn’t worth getting new batteries, so I sold all the tools on eBay and chose another platform. Then, the reviews were vital. I read a lot of Stuart’s back catalog of articles, and many other people’s too. It was really important that I chose the right platform for me. I chose red. Yellow would, I’m sure, have been just fine, but cost, availability and price/performance (in a very general sense) at that moment were the deciders. I don’t regret it, but I’m sure 20V Max would have left me feeling just as good. Since then, choosing the next tool has been relatively easy, and specs have mattered. But torque is just as good for me as UWO would have been.
My final thought is that there really is no perfect answer. Specs help, but they won’t ever lead us to the best tool. (Example – my most powerful drill is a country mile ahead of any of my others. 1500W! Wow! But I hate it viscerally. It is cheap junk and I begrudge every one of the pennies I spent on it. I actually hurts me to use it, it is so brutal ad hard to control.) We should relax, be content that like every other human being, we are not machines and choose based on subjective as well as objective criteria. And then spend time enjoying the choices we make – so long as Stuart helps us make the right choices for us!
aj
Watts out is the best measure for tool performance.
However, I’m not sure DeWalt knows what a watt is.
They incorrectly rate watt-hours on their batteries. Yes you can measure 20V and yes you can measure 5.0 amp-hours. But there is no possible way to get 100 watt-hours out of that battery because the voltage will average 18 or less over the discharge.
Charles in Richmond
I’m starting to think SBD is drowning in marketing nonsense. A shame, as they used to be a good tool company.
Currently, on jobsites, m18 is killing it. Than Makita (excellent system, I’ve got a gazillion, but I’m migrating to m18). Dewalt is dying off on jobsites, as people compare to other tools, but still has holdovers.
These days I’m actually shocked whenever a dewalt tool is quality. And yet I was 100% dewalt almost in 2005.
In the real world, the plastic gears in my dewalt 18 impact melted when I built a deck. Repaired under warranty, but even the dewalt repair shop at the time had nothing good to say about the interior parts. That’s when all jobsites started switching to Makita in eastern Mass. Now if I need power I go hunting for who took the m18 brushless.
Mike
HP = Torque ft-lb x RPM ÷ 5252
373 UWO is 0.50 HORSEPOWER (1HP = 746W)
Graham
This would be very useful if torque ratings from manufacturers were given at a specific rpm, but they’re all at 0 rpm, that I know of, since that’s where peak torque of an electric motor is.
So if I plug that in with, say, 250ftlb,
(250 x 0) ÷ 5252 = 0
That’s not helpful at all.
Now if I’ve got an impact that does 250 ftlb at 200 rpm,
(250 x 200) ÷ 5252 = 9.5hp (~7000W)
That’s awesome, but no electric impact or drill is pulling that off.
Jonathan Phillips
Unfortunately, it is easy to confuse watts with uwo. Since most engineers aren’t real creative with acronyms, and just smart enough to give marketing something to promote, I’d guess that uwo stands for Useable work output or unit watts output. The number they give is never followed with any label, which leaves us guessing the real words behind the acronym and if it’s per unit watt, then the numerator also needs to be watts or without unit such as revolutions or radians. Fortunately, the European consumer agencies weren’t impressed, and if you search European sites you can find torque numbers. This is how I learned that my old 18v actually could produce more torque than the early brushless models. Which is why I didn’t buy into the 20v system until this year.
Torque at zero rpm on the new drills, if you have it truly locked up is zero because the power control software won’t allow self destructive balls to the wall power, which could easily lead to battery fires and lawsuits and lost reputation.
Ray Adams
I am dis-appointed in Dewalt, If I need a specific amount of torque I cannot find that the Dewalt tool may not have enough power? I am not going to do a math conversion before buying a tool. Many lug nuts on a car requires 120
Ft. Lbs. I do not know if the Dewalt tool is sufficient? Some bolt tightening
requires 100 Inch. Lbs. I do not know if the Dewalt tool is sufficient. Just based upon the amount of discussion in this Email, Dewalt is only confusing the issue. I have been buying Dewalt for 30 years, it is time to switch to Milwaukee.
Stuart
Dewalt rates their cordless drills in UWO. Their impact drivers and impact wrenches are spec’ed in inch-pounds or foot-pounds.
Ray
Reading your article my college physics came back to me !
Stuart
Woo!
Jonathan Phillips
I love DeWalt tools, but coming from an engineering background, I hate the UWO. It was invented to purposely confuse consumers at any level by eliminating comparables that people understand. Torque tells you how big a bit that drill will turn. To some people it doesn’t matter how fast it turns as long as it turns! So max torque happens on the lowest speed setting, duh. NOBODY looks at power numbers in terms of drilling. That requires maximum cutting efficiency, bit design, lubrication factors, heat buildup, material being processed, and yes, torque times rpm to figure power output. And then there’s the ratings on the batteries where you could actually calculate motor and transmission efficiency, because electric power from the battery is volts times current, just like with household electric. So if the motor is 90% and the transmission is 95%, you multiply the two and get the system efficiency. These are things people can google and calculate and make educated decisions with. DeWalt has chosen to obfuscate, obscure, and basically lie to their loyal customers and to potential new customers because they knew that the competition was going to catch up! But who cares. The best strategy is to stay ahead of the competition with product development and quality and new features. It’s no wonder they are struggling. Sad really.
Brett
This was a great article. Thank you for a well-written, in-depth explanation of torque vs UWO.
muftakis
I still cant figure this out.. i have dcd985 drill how to identify each torque setting in nm or in-lbs??!!
Pls help
Stuart
According to Dewalt UK, here are specs for the Dewalt DCD985:
Max Torque (Soft): 38 Nm
Max Torque (Hard): 80 Nm
KSanger
I once worked. I was predicting color to within a tolerance measured using industry standards. But was unable to tell customers what the units were. Marketing wouldn’t let us as they were afraid the customers would hold us to the estimates and complain when they were unable to reproduce them. We estimated the color and the standard deviation. All we could do was tell the customer that the lower the number the better the estimate.