Milwaukee Tool currently offers Cordless M18 FUEL and M12 FUEL Straight 1/4″ Die Grinders and only offers a right angle 1/4″ die grinder in an M12 FUEL version. Choosing the right die grinder for your uses will depend on the job you need to complete and the amount of room you have to get the tool into.
The video above is Milwaukee Tool’s newest die grinder, he M12 FUEL Straight 1/4″ die Grinder. This model is very compact and offers 3 speeds with a maximum RPM of 21,000. The tool is the perfect size for use with a 1/4″ x 1/8″ Reducer Collet Reducing Adapter. If you do not have one, you should check that out! With the size of the tool, it is best used for getting in tight places and cutting or using a smaller burring tool. We also had great luck with this tool using a Rotary Thread File for correcting nuts and bolts that have poor threads. This unit is not made for putting down large amounts of power, nor for completing large jobs unless you upgrade to the 6.0 Ah M12 Battery.
Milwaukee Tool M12 FUEL 1/4″ Right Angle Die Grinder is the first cordless right angle die grinder on the market. There have been M12 sanders and polishers that can be fitted with 3M Roloc pads, but never one with the versatility of a die grinder.
Milwaukee Tool always wants to properly compete with the tools that Mechanics are using, so they worked to provide more power than cordless models. Another benefit to going battery power is the ability to use the 4-Mode RPM control and variable speed trigger to know what the max RPM will be. This allows for a larger range of attachments that might have lower RPM ratings, and the mobility to fit in the tightest spaces. The right angle die grinder has a max RPM of 24,500.
This tool is best used with 3M Roloc 2″ Disc Pad Assemblies. Our most favorite is the 3M Roloc Bristle Disc but they also make a Scotch-Brite style pad in different grades that will clean metal up very well, like the 3M 01397 Green Corps Roloc.
The oldest and most powerful cordless Die Grinder is the Milwaukee Tool M18 FUEL Die Grinder. Milwaukee Tool claims the M18 FUEL Die Grinder (Model 2784-22) was the first brushless die grinder in the world. This cordless M18 die grinder delivers corded performance with over 20 minutes of grinding per charge with a 5.0Ah battery.
Milwaukee’s M18 FUEL, ¼” Die Grinder delivers 20,000 RPMs and has a maximum capacity of a 3” flap wheel. In our shop, we stay away from those sized accessories because it would drag our corded models down. Milwaukee designed the die grinder to have a very similar feel to the M18 angle grinder. The main difference, other than the heads of the tool, is the slide switch on the die grinder. The slide switch is easily operated with one hand by using your thumb to slide the switch forward and allow it to lock the tool on the on position. The cooling intakes are covered with the same dust screens used on the M18 angle grinder. Features 20,000 RPM brushless motor is designed to deliver corded performance. Fits all 1/4″ shank accessories but would also benefit from a 1/4″ x 1/8″ Reducer Collet Reducing Adapter for smaller jobs. This tool is mostly used with Double Cut Carbide Rotary Burr Sets in our shop.