Milwaukee Stubby Impact 1/2" VS. 3/8": Mechanic Buying Guide

Milwaukee Stubby Impact 1/2″ VS. 3/8″: Mechanic Buying Guide

You have probably seen some videos on YouTube of people using their awesome stubby Milwaukee impact wrenches and wanted to do some more research before deciding on buying the 1/2″ version (Part No: 2555-20) or the 3/8″ drive stubby (Part No: 2554-20).

Well, which Milwaukee stubby impact drive size is better for the DIYer or professional mechanic, the 1/2″ (2555-20) or the 3/8″ (2554-20) version?

Most professional mechanics agree the point of buying a stubby impact wrench is to get into tight spaces easily. Therefore, a stubby impact wrench is best paired with a 3/8″ drive as you will be using it for tighter spaces and smaller fasteners. Don’t worry, the 3/8″ Milwaukee stubby combined with one of the Milwaukee high output m12 batteries will put out plenty of breakaway torque to also quickly remove most lug nuts from all cars and light duty trucks. If you are looking for a 1/2″ cordless torque wrench then skip the stubby version first and go straight for the m18 Fuel 1/2″ High Torque Impact Wrench that everyone loves. The 1/2″ high torque Milwaukee combined with the 3/8″ stubby impact wrench should cover most of your needs for car repair. Throw in an m12 1/4″ cordless ratchet (fuel) in the mix and you will be able to handle fasteners from big to small, and from huge torque numbers to the smallest of 8mm bolts. 

Why the 3/8″ Stubby Makes More Sense:

Why not take advantage of the smaller 3/8″ sockets on a stubby impact wrench? The whole point of a stubby impact wrench is that you can fit it into tight spaces. When you have a stubby impact with a 1/2″ drive all the sudden your sockets are much larger in general and you lose out on all the space savings by having a stubby wrench.

Another big reason many people choose the 3/8″ stubby impact over the 1/2″ version is that neither of these is made for high-torque applications. Yes, these stubby wrenches paired with a good 6.0 Ah battery will rip off lug nuts on pretty much every car, but they are not made for heavy-duty applications. You shouldn’t be picking this gun up to take off CV axle bolts or high-torque suspension parts. When you encounter a bolt or fastener that it can’t take off, just grab your breaker bar and break it loose first then switch over to the impact wrench. It really isn’t that hard and is a great way to keep your tools working longer.

Really the 1/2″ drive stubby impact wrench for Milwaukee is fun to own if you already have the other Milwaukee cordless tools. Some people just love having a full set and can’t live without owning every cool tool that their favorite brand puts out. If this is you, then why are you even reading a review? Just go buy it already!

Fuel Matters:

Just as a general rule of thumb when buying Milwaukee tools it is best to get the “Fuel” versions when you can afford it. The big difference between the fuel tools vs. non-fuel is that all tools labeled “fuel” come with a brushless motor. A brushless motor basically means longer battery life and more power. The tool also tends to last longer as electric motors that have brushes need to have their brushes replaced after heavy use.

It is a lot of marketing jargon and I know it can be frustrating as a buyer. There are so many options for different tools and batteries, but the one thing to keep in mind is that brushless motors are the future in cordless tools. If you want the most power and reliability stick with brushless tools– especially from Milwaukee (Fuel).

Best Deals On Milwaukee Stubby Wrenches:

Here is the best deal I found on Amazon for the (3/8″ Stubby m12 Milwaukee Fuel Version Bare Tool 2554-20 Impact Wrench)

If you really do want to buy the 1/2″ stubby version then here is a great deal on the bare tool on Amazon– 2555-20.

Related Questions:

I wrote a long article all about Milwaukee’s return policy, read that if you want to know more about how to warranty these tools. The basic gist is that Milwaukee has one of the best warranties on their cordless impact tools and batteries. It is better than Dewalt, Makita, Snap-On, Matco, Mac, etc., and the price of their cordless mechanic tools are very competitive.

For example, you can get multiple tools and batteries for the same price as just the 1/2″ high-torque Snap-On Cordless impact (which costs like $800). Plus, many mechanics have reported problems with the Snap-On cordless tools– and just because it says they are Snap-On in 2019 DOES NOT mean they are made in the USA. Here is a guide I wrote all about figuring out what tools made by Snap-On are still made in the USA.

Here are some questions people frequently ask when thinking about what stubby impact to buy.

Do the m18 batteries fit the Milwaukee stubby impact wrenches?

Answer: No, the m18 and the m12 are two different battery system and tool lineups from Milwaukee. Make sure you buy the correct batteries for each tool or buy them as part of a kit (with the tools and charger included). Most of the time the Milwaukee battery chargers can charge both m12 and m18 batteries, so you may be able to use one charger for both systems. I highly recommend buying the higher Ah (amp hour) batteries for the m12 and m18 systems which give your tools added torque busting power and longer battery life.

Will any m12 battery work with my stubby impact wrenches? 

Answer: Yes, any m12 battery from Milwaukee will work with any m12 tool. You should be running higher amp hour batteries with these tools to get the maximum performance. Which is why it can make sense to just buy the bare tool then buy an upgraded battery separately to save some money.

Here is a link to higher amp hour batteries in the m12 lineup, and an m12 battery charger should you want to buy them individually.

Is the Milwaukee 3/8″ better than Snap-On 3/8″ Cordless?

Answer: Yes, the Milwaukee 3/8″ stubby impact is hands down better than the Snap-On version. With Snap-On cordless tools in 2019, you are basically paying for the Snap-On brand and logo. The Snap-On cordless tools are made overseas just like the Milwaukee and come with a lesser warranty. Plus, you pay like 2x or 3x the price for Snap-On cordless tools and many professional mechanics claim they really suck when it comes to torque. You will be hard pressed to find many professionals that have used both Milwaukee and Snap-On cordless and still claim Snap-On tools wins.

What is the best battery to use with my Milwaukee stubby impact?

Answer: The best m12 battery to use is the highest amp hour m12 battery they have currently on the market. If you are just going to use the small m12 batteries that come in most Milwaukee kits then you will find the stubby impact will use a battery pretty quickly. Think one battery per every tire rotation (or like removing 20-30 lug nuts) and the battery will be dead. However, with a battery like the 6 amp hour m12 battery, it may last you for most of the day and you can have the smaller batteries as a backup or for tight spaces.

What is the breakaway torque of a Milwaukee Stubby Impact?

Answer: The newest fuel versions of the Milwaukee stubbies claim to have around 250 ft-lbs of breakaway torque. Most users are finding that to be a little inflated, but they have no problem removing lug nuts tightened up to around 125 ft-lbs. Which on most cars and light-duty trucks is basically all you will be removed anyway. This is not the tool to be buying if you are someone that is just using it for tire rotations, for that you will want to grab the 1/2″ high-torque Milwaukee m18 impact wrench.

Can the Milwaukee Stubby 1/2″ and 3/8″ impact wrenches handle suspension work?

Answer: No, they are not the right tool for heavy-duty applications. I know I keep saying this over and over, but people keep buying the wrong tools for their applications. These tools are designed so that you have mid-torque breakaway power in a short and easy to use stubby impact. These are not designed to be a heavy-duty diesel mechanics main gun for suspension work. However, these tools really come in handy in tight spaces and offer amazing breakaway torque values which mean you will honestly use these tools probably more than anything else in your box.

How much do Milwaukee stubby impact wrenches weigh? 

Answer: Milwaukee stubby impact wrenches are around 5″ in length (from the anvil to the back) and weight around 2.6 pounds without a battery. Compare that to the 1/2″ high torque M18 impact wrench and you are looking at around 3x the weight at 6 pounds before adding a battery.

What is the difference between 2555-20 and 2554-20?

Answer: The 2555-20 is the stubby Milwaukee 1/2″ drive part number and the 2554-20 is the 3/8″ drive version, both with the anvil ring (preferred by mechanics over the detent pin version). The kit part numbers (to get the impact wrench with a charger and battery for both) are for the 3/8″ kit 2554-22 and the 1/2″ kit 2555-22.  All links go to some awesome prices I found on Amazon for the tools.

Where can I buy a protective boot for my Milwaukee stubby impact wrenches?

Answer: You can find the protective boot that fits all m12 Milwaukee stubby impact wrenches on Amazon here (just order one for each stubby you want to cover). The part number from Milwaukee for the m12 stubby protective boots is (49-16-2554). I recommend buying a protective boot if you are working on cars. It helps protect the tools from damage if dropped in oil or if they fall off the lift onto the floor. Don’t worry though Milwaukee also offers a 5-year warranty on your tool (just maybe don’t mention you dropped it in transmission fluid).

Do the stubby Milwaukee impact wrenches actually have 250ft-lbs of breakaway torque?

Answer: Yes, given the right conditions the Milwaukee stubby impact wrenches can definitely break a bolt loose that is torqued to 250 ft-lbs. But that is right around the maximum they can handle, and it is not the tool to be breaking 250ft-lbs bolts loose with.

Why would you do that? It will use up your battery fast, put stress on the anvil on the tool, and be loud and slow. These are not the tools you want to be used if you are just looking for big breakaway torque numbers. But yes, if you were curious they do test out okay and Milwaukee’s number of 250ft-lbs of breakaway torque isn’t just marketing– they can actually do it. Just remember there are more variables than the tool itself which can change the amount of torque needed to loosen a fastener including battery amp hours, state of charge, size of impact socket, size of fastener, extensions or adapters used, and temperature.

Do extensions make my impact lose torque power?

Answer: Yes, using extensions on your impact wrench will cause a loss of torque. How much? It depends on the length of the extensions and whether they are impact rated or not. I highly recommend never using non-impact sockets or extensions with any impact tool.

This is because they will absorb more of the impact from the tool and not transfer it into the socket. Using chrome sockets or extensions on an impact wrench can also cause damage to the anvil, and when you go to warranty your tool Milwaukee may spot the damage and know that it was used with chrome sockets. Seriously, that happens. Using impact extensions will cause less of a torque reduction than chrome extensions.

Are the different torque settings helpful on the Milwaukee Stubby Wrenches?

Answer: The most awesome feature is the setting on the Milwaukee stubby that is known as the drive control setting (the fourth setting). It basically allows you to tighten any size fastener fast without the worry of stripping or breaking it because as soon as the torque wrench starts hammering it will shut itself off. Meaning you can rip down 20 10mm transmission pan bolts quickly then come back and retorque them. You don’t have to pay attention anymore just rip at full throttle on the Milwaukee stubby and it will stop itself before over-torquing anything. The other 3 settings on the Milwaukee relate to different torque levels, 1 being the least amount of torque and 3 being the highest.


The Milwaukee stubby impact line up combined with their high-torque impact wrench and the cordless impact ratchets mean Milwaukee usually wins in the cordless tools for mechanics lineups. Many mechanics love their Dewalt tools or Snap-On hand tools but you will find the Milwaukee cordless tools in their toolboxes. Pretty simple, they offer the best options, longest warranty, and hardest hitting torque. Plus they look pretty friggin’ cool as well.

For more information and to see an in-depth review of the Milwaukee Stubby m12 lineup watch this video:


One Comment

  1. I’m a home/DIY guy doing what I can on the five cars in the family, one of which is a sorta-crusty old BMW. I got the 1/2″ Stubby so I could have a single set of impact sockets – seems like there shouldn’t be many places where I’m going after smaller bolts/nuts where I can’t get it by hand if needed – can you give some examples where I might run into trouble? My understanding was that the 1/2″ anvil would also offer more capture of the potential of the motor too – thoughts. I’m now debating whether I need to keep the M18 FUEL Mid, High or both. I got an great deal on both, but I’m wondering where the Mid is needed when the Stubby can’t deal and the High won’t fit.

    (I agree with your comment on the 1/4″ Impact too – fantastic for so many things)


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