Tool Fight: Bosch 12V Impact PS42 -vs- Milwaukee M12 FUEL Impact

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Bosch vs Milwaukee 12V Mechanical HubSometimes in order to get a true sense of how a tool stacks up against others in it’s category there is no better way to find out than pitting it against other tools in a head-to-head battle. You may have read a recent review of the Bosch 12V impact driver (PS42) here on The Hub and if you have you’ll know there was mostly positive feedback from the three ProStaffers who worked with the PS42 but also a couple notes of contention from myself. Mainly my reservations against the Bosch impact driver were based on my longtime work experience with the Milwaukee M12 Fuel impact driver [2453-22] and its now almost five years at being one, if not the best in the 12V category. So naturally I was curious if my claims of under-powering were true about the Bosch 1/4″ driver.

Some notes on the comparison:

Both impact drivers are built with brushless motors. The EC Brushless motor and drive system puts out no-load rpm numbers of 0-2600 [speed 2] and beats per minute (bpm) of 0-3100 [speed 2]. Typically the telling rating of torque is what most buyers will look at which the Bosch puts out 975 in. lbs.

The Milwaukee on the other hand puts out a class leading 1200 in. lbs of torque with the FUEL motor and drive system. No-load rating for rpm’s are 0-2650 [speed 2] and bpm 0-3550.

Each impact was mated to a 2.0Ah battery pod, and each were fully charged. My personal preference for drilling small diameter holes for water piping and heating lines has me constantly reaching for my 12V impact driver and loading it with the Irwin Speedbor MAX tri-flute self feed drill bit. Each of the impacts were loaded with unused 1′ diameter, 1/4′ hex chuck drill bits.

The test I used was that of a typical residential or wood-frame commercial wall in which I stacked two 2″x8″ Douglas Fir boards in my Rockwell JawHorse vise. With identical bits, fully charged battery packs and identical requirements I started both impacts at the same time in a head to head match. Here is the test:

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I never expected that!

To be completely honest I expected the M12 to win. By the numbers it had every advantage but in this case the rpm’s of the Bosch and the smooth motor and drive technology may have been the difference that kept pace with the er hitting Milwaukee. My view on the Bosch has changed slightly from our PorStaff review; I have always maintained that the PS42 by Bosch is well built but now I feel my comments of being under-powered were slightly misguided. I have used the impact for a few months and at times felt it fell short of my previous favorite (the M12 FUEL) but I did know the ratings and hadn’t pitted them in a head-to-head battle. Both are very impressive tools and worth a look without a doubt. A lot of professionals skip the 12V tools and write them off only to insist that anything less than 18V power is not worthy of their time or money. Honestly, that’s a result of experience with old outdated technology and misinformation or lack of new tool education. Today’s brushless 12V tools are powerhouses that get the job done in a lot of arenas. I’m happy we were able to test the Bosch because now I have a second favorite impact on the truck!

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