Mac 12V 3/8″ Impact Wrench – BWP038


As you know, we recently reviewed Mac’s new 20V 1/2″ BWP050. It was a great performer and really surpassed my expectations. Aside from the placement of the LED light, it really didn’t have any downside. I loved the gun and intended to use it on our race trailer, but I quickly realized it was simply too much gun for an ATV application. Aside from the size, the level of power the BWP050 offers could easily damage the aluminum covers and housings.

I really like the platform and seeing how we’re using the Mac 12V ratchet (reviewed HERE), I really wanted to stay with it. The BWP038 fit the bill perfectly.

Mac 038 2



The BWP038 has all the features of it’s big brother (minus the crazy torque), in a smaller, lighter, package. From the compatibility with Dewalt’s 12V Max platform, to the smart charger system and automotive fluid resistant body, the 038 is built to work. As with the other 12V tools, it does not feature a battery status gauge like it’s 20V brother. It features the LED under the bell housing, and while it hindered the lights performance on the 20V, it performs much better under the smaller bell of the 038. The variable speed trigger, cushioned rubber grip, hog ring style anvil, and protective bumpers, give the 038 all the convenience the mechanic is looking for.

 As you can see, the BWP038 offers a much more compact stature than the BWP050

As you can see, the BWP038 offers a much more compact stature than the BWP050



Max. Torque: 150 ft-lbs / 200Nm

Max RPM:      1,700

BPM:             1,900

Weight:          2.6 lbs. *

Length:          6.75″ *

Height:          8.25″ *

Warranty:      3 year tool / 2 year battery

* Measurement taken with battery installed



In all honesty, I had never wanted a 3/8″ impact wrench prior to now. I guess I’d never really stumbled upon the occasion where I couldn’t get by with a 1/2″ gun, but as soon as I popped a socket on this thing and put it to work, I realized what I’d been missing. At 150 ft-lbs of torque, we aren’t going to be popping off 1-1/2″ trailer hitch nuts or Honda crank bolts, but we don’t want to. The compact size, light weight, and everyday practicality is kinda the appeal isn’t it? Make no mistake, the 038 is a hard hitter for such a little guy, but it’s still very practical for the assembly and disassembly tasks you’ll do every day. It also seems to handle even long extensions well.

Mac 038 5

Our primary uses for the gun will be removing the clutch/transmission cover, lug nuts, and suspension bolts on our racing quad. The highest torque rating on the bike is in the 120 ft-lb. range, so the 038 is exactly where I wanted to be torque wise. With a length under 7″ and height just over 8″, it’s pretty easy to maneuver around nerf bars and suspension components. I appreciate the fact that it still feels like an impact wrench as opposed to that cordless screw gun feel some compact models have. A matter of preference I suppose, but worth mentioning. For the automotive guys, the 038 is compact enough for a lot of tasks in the engine compartment. Messing around under the hood of my full size pick-up I was able to get on many of the fasteners that would usually require a ratchet. With some extensions and a U-Joint, I’d say you could get on a lot more.

Mac 038 3Mac 038 4

Mac lists the gun at 150 ft.-lbs. of breakaway torque and doesn’t list a forward torque rating at all. We covered the reasoning behind this in our BWP050 review, and while I understand the logic behind not publishing them, I wouldn’t be much of a tool writer if a just told you what you already knew. With the crazy torque output of the 1/2″ gun, it’s really difficult to do any scientific testing without very expensive equipment, but with the everyday torque rating of the 3/8″ gun, torque tests are well within our capabilities.


Breakaway Torque Tests 

Using my 1/2″ Proto torque wrench which is known accurate (20-25 cycles since last calibration), I torqued the nut on a 19mm course threaded ROPS bolt on my tractor to 150 ft.-lbs. Try as it might, it just couldn’t bust it. I dropped the torque to 140 ft.-lbs. and it still wouldn’t bust it. I dropped to 135 ft.-lbs. and it finally broke loose. I then increased the torque rating in 1 ft.-lb. increments until it wouldn’t come off anymore. On this fastener it topped out at 138 ft. lbs. of breakaway torque. Not too bad when you consider that 19mm is on the very upper end of the normal operating range for 3/8″ drive.  I repeated this same test on a fine threaded 13mm frame bolt and was able to bust it loose up to 141 ft.-lbs. While we never achieved the 150 ft.-lb. the gun is rated for, we were very close and it is certainly plausible that it could under optimum circumstances.


Forward Torque Tests  

Most manufacturers don’t focus too much on forward torque ratings and due to the many variables, some (including Mac) don’t publish one at all. This isn’t as precise a test with a torque wrench as reverse torque, but we were able to establish a pretty decent operating range. I tightened up a dozen or so fasteners from 10 – 19mm with different arrangements (nuts and bolts, with and without washers, lock washers, course and fine thread, etc.) and got pretty consistent performance around 55 ft.-lbs. I was able to get some of the smaller sizes up slightly over 60, but even on the 19mm stuff I was getting at least 50 ft.-lbs. Again, this is in no way a precise method of testing, but it does give you an idea of what you can expect.



The BWP038 is another fine additional to the Mac cordless lineup. For the lower torque requirements, aluminum components, and tighter spaces on our racing ATV, I really can’t imagine anything better suited for the job. When used in conjunction with the 12V ratchet, our repair times should be drastically improved. The BWP038-S2 kit (2 batteries) retails for $299 on Mac’s website (which is currently being upgraded). You can also purchase the tool bare, although it isn’t available online and will have to be purchased on the truck. Like the other Mac cordless tools we’ve reviewed, the 038 comes with 1 year free service in addition to the standard warranty. If you’re like I used to be and use 1/2″ for everything, you can get the same compact gun with a 1/2″ anvil and 50 extra ft.-lbs. of torque (200 ft.-lbs.) as the BWP050C for the same price. Oddly, the 1/2″ Compact IS available online as a bare tool for $199.

As for critiques, once again, our only real wish is for a 5 year warranty on the tool. It’s not a huge deal, but it would make an already awesome tool that much “awesomer” (Yes, I am fully aware awesomer isn’t a real word).

As always, stay tuned to TIA for more from Mac Tools!




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