I recently tested Milwaukee’s M12 Gen II Stubby 1/2-inch Impact Wrench. The size-to-power ratio drove me crazy. It’s remarkably powerful for its size, yet small and light so you can take it anywhere and use it all day without a problem. But as good as it already is, Milwaukee could have made it even better.

Milwaukee’s M12 Gen II Stubby Impact Wrench linehas been expanded with the addition of the 3/8-inch version. It sent one over for review along with the 1/2 inch model. While you may be quick to write off the differences, there is a big advantage to the smaller unit. It is what I would consider the perfect impact wrench for a roadside kit or any other job that takes you out of the shop.

Bottom line

The specifications

The only difference Milwaukee’s Gen II Stubby 3/8-inch drive is the size of the anvil. It means that all good things carry over. Again, that includes the absolutely wild PTO despite its compact size.

The M12 Gen II Stubby delivers an astounding 550 foot-pounds of breakaway torque. That’s a lot of grunt from a tool that’s smaller than most impact drivers and weighs next to nothing. It comes in at 2.2 pounds without a battery and 2.7 pounds with one 2.5 Ah battery. Installation of 5.0 Ah battery bringing the total weight to 3.2 pounds.

The 4-mode ride control also carries over. Modes one through three are simply gradual increases in speed and power, with the fourth mode being Auto-Shut Off. Modes are selected by placing the drive unit in neutral and pressing the trigger twice. The 3/8-inch Gen II Stubby also shares the same $199.00 price with its 1/2-inch counterpart.

Features Milwaukee’s Gen II M12 blunt impact wrench

Performance testing of M12 Gen II 3/8-inch Impact Wrench consisted of using it for a variety of jobs around the shop and outside of it. I recently started tearing down the 4.7L V8 in my 2003 Ram 1500. This has seen me through a lot of the work alongside the 1/2 inch version. I also tackled some suspension jobs and took it for a trip to the junkyard.

In the case of the 3/8-inch model, the maximum power is nice to have but not always necessary. You will almost never come across a fastener that this tool is intended to work with that requires nearly 550 foot-pounds of torque. Most of the time I leave it at the second power level setting. This setup is more than capable enough for most fasteners but isn’t so powerful that you need to worry about breaking things. The third mode is mostly for special occasions.

Still, the compact size fits nicely with extreme power. When working under a car or in an engine bay, you don’t have much room, if any, to get a larger shock or breaker bar in there. This has no problem getting in and going to work. Weighing just three pounds, it’s also easy to handle for long periods of time. And that kind of power means you don’t have to stop and change tools, even when you have room to do so. It will be the only impact wrench you need for many jobs, and it really adds value.

The insane power-to-weight ratio is really good even outside the shop. When building a roadside kit or to-go tool bag for junkyard trips and other remote jobs, the key is to keep things simple but effective. You want to bring as few tools as possible and will likely build your selection around that 3/8-inch drive socket. This allows you to throw a spanner into the mix that actually is can handle nuts and other larger fasteners. Walking around the junkyard, I barely noticed the extra weight in my tool bag. And while I was lucky enough not to need it on a recent road trip in my ’69 Charger Projectthe small size allowed me to build a fairly light and space efficient torso tool kit. While I have tons of trunk space to work with, it’s nice to have room for cargo and other necessities.

The verdict

Overall Milwaukee Gen II 3/8-inch impact wrenches is a big win for Milwaukee. They’re almost a cheat code for the minimalist because they work so well for so many occasions. The pricing isn’t too bad either. $199.00 for the bare tool and the batteries that come with it will bring the total investment close to what you will pay for some high torque impact wrenches– even more in some cases. But the power-to-weight ratio really adds a ton of value to it. At 3.2 pounds, it’s a tool you can use all day and easily throw in a tool bag. The ability to dish out 550 foot-pounds of torque makes it a great choice as your primary impact wrench in professional and DIY environments. Again, you’ll rarely, if ever, call on the max power of this thing. Still, it makes for a combination that you’ll realistically get more use out of than many full-size models.