Milwaukee 2101-22 M4 Screwdriver – 4 Volts of Joy!


When you think about 4 volt tools you usually think of Ryobi’s 4V Tek platform, which is a good platform for the home owner.  Well, now Milwaukee tool is sharing some 4V love with the M4 screwdriver for the pro.  This pocket driver for the pro is quite handy to have around.  Like the DeWALT DCF680 that we just recently reviewed, this is designed for those light duty jobs like trim plates and ceiling boxes, and even cabinets.  Anywhere precision is needed and a standard 18V or even 12V is overkill, the M4 is the tool to use.

The 2101-22 has 2 configurations, a pistol grip mode and a straight shaft mode for getting into those really tight areas.  One thing that the M4 is lacking, that is kind of a big deal, is an LED light.  It really needs an LED light!  A few times I found myself lacking light and didn’t have a flashlight with me.  The unit has momentary, a forward and reverse switch.  There is no variable speed here.  It’s either 200 or 600 RPM, depending on what speed you have it on, 1 or 2.  The unit puts out 44 in lbs of torque which will drive a 3″ screw through a 2×4. There’s more than plenty of power for all the tasks you can throw at it.

The one-handed 1/4 hex will also hold 1″ bits.  Power can be controlled by the 21 clutch settings.  I really liked the clutch feature. It powers off after it clutches out in forward. This gives it a really precise, quality feel. In reverse it works like any other driver clutch.  2 batteries come with this kit and the included charger will charge them in about 45 minutes.  A fuel status gauge built into the side of the tool will keep you up to date on your charge status.  Overall, the M4 is a great tool for those who need a precise, small driver.


  1. Great writeup Dan, I am looking forward to see what manufacturers have in store for these smaller volt lines. A tool fight would be neat to see the big difference in volts with the 8v DeWalt. Milwaukee is usually really good about having lights on there tools…..I wonder what happened there..I wonder why it takes longer to charge these smaller volt batteries, 45 minutes for this, 1 hour for the DeWalt…? Keep up the great work!

  2. This is one of those tools I would want to keep in my go to tool bag. Not as nimble as other compact foldable drills but still very useful. Like Chase said, that charge time is a while especially since Milwaukee’s m12 can recharge in 30min. I suspect it is because they don’t have any quick charge circuitry in the battery. Just like the Dewalt’s gyro screwdriver. I’m actually surprised Milwaukee did not update this tool during their recent new product release event. You guy’s are rocking a review a day. Wow. Your amazing!

  3. I have the makita 4v and it was a time saver when i change my hard drive i whish it was 45 min charging time but it takes 3 hours 🙁

  4. This tool seems good but no light, no variable speed and long recharge keep it from being great. It wont make me switch from my m12 brushed screwdriver. Now thats an excellent tool. Everyone Ive come across love that thing from fellow workers to friends and family. I just used it to remove and install 2 ceiling lights. Well back to the m4 screwdriver, Ive always thought this and the dewalt 7.2/8v max screwdrivers were shaped awkwardly and too long. Ive never held one so maybe it would make sense if I held one.

  5. For those wondering why it takes so long to charge the battery – It’s partly due to the lithium ion cells that are used. When the manufacturer makes the cell, they have to optimize it for either energy capacity (long runtime), or power capacity (how much power it can instantaneously deliver). This is similar to lead acid car batteries, in that you have high capacity deep-cycle and high power starting batteries.
    So – because the cells used in these single cell (3.6V nominally, but 4V if you’re a marketing exec) screwdrivers don’t need to deliver as much current as say, a cell used in a battery for a cordless circular saw, the manufacturer can use a higher capacity cell. HOWEVER, you can’t charge energy cells as fast as you can power cells (think 15 minute/30 minute chargers). In fact, depending on the cell used, the manufacturer recommended charge rate may be as low as 0.2C (or 0.2 x the capacity of the battery), though typically the charge rate is 0.5C. For example, lets say i have a 2400mAH (or 2.4AH) cell. to charge it at 0.5C, I would need to charge at a rate of 1.2 amps, and it would take approximately 2 hours to charge (1.2 amps x 2 hours = 2.4 amp hours). In contrast, a 1500mAH power cell can be charged as fast as 4C or 6 amps and should charge in approximately 15 minutes.

    On a side-note, I have a strong suspicion these are made by Panasonic for milwaukee like the oldschool 2.4V screwdrivers – true workhorses and built better than most anything TTI is used to spitting out (tek4, i’m talking to you with your plastic screw-on battery cover). I have two of the panasonics and one milwaukee and they’re the exact same thing with different colors.


  6. I purchased one of these for an assembly project I had underway. It was great to have a battery inline screwdriver but I had one small issue the screws were inserted at different torques leaving me with runtime issues.


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