Milwaukee M12 Pin Nailer

Milwaukee M12 Cordless 23-Gauge  Pin Nailer 2540-21

Milwaukee M12 Gauge Pin Nailer

Manufacturer: Milwaukee
Model number: 2540-21
Price: 249.00
Power source: M12 cordless
Motor size: Nitrogen Tank
Weight: 3.3 lbs
We recently tested the Milwaukee M12 Gauge Pin Nailer 2540-21. The new pin nailer runs off of Milwaukee’s M12 battery platform.

This pin nailer weighs 3.3 lbs. and drives 23-gauge headless pin nails ranging in length from 1⁄2” to 1-3/8″ and is best suited for the most delicate of trim pieces, tiny furniture trim, and super thin veneers where other larger-gauge guns might split the wood.

23-gauge pin nailers leave a tiny and barely visible mark on the wood, which is huge when dealing with prefinished molding and trim, for us that translates mostly to finished kitchen cabinetry and molding.

Milwaukee M12 Gauge Pin Nailer Specifications

  • Nail Length: 1/2” to 1-3/8”
  • LED Work Light
  • Reversible Belt Clip
  • Battery Fuel Gauge
  • Secondary Work Contact Tip
  • Magazine Reload Indicator
  • Tool-Free Depth Adjustment
  • Weight (w/out battery): 3.3 lbs
  • Warranty: 3 Years

Safety Trigger

Milwaukee chose to use a traditional-style double trigger system vs. a contact tip, and I’m glad they did. If you’ve used pin nailers on small trim parts you know that the contact tip when depressed, can move your trim piece – the double style trigger eliminates that frustration.

The M12 pinner has a dual trigger system. The first trigger serves as the safety switch, and you need to pull it to disengage the switch. Then you need to pull the second trigger to fire the pin into the workpiece.

One interesting feature on the trigger that you may not know is that the M12 pinner has an electronic time-out on the secondary trigger. If the trigger is held down for more than 40-seconds and NOT fired the tool will shut off and you will need to recycle the trigger to activate it.

I think this is a great feature but the time should be reduced to 20 seconds.

Nice Features Not Easily Noticed

If you look fast you’ll miss some interesting features on this pinner.

Magazine Magnet

When loading the pins into the magazine if you look close you’ll notice a small magnet. Missed by many, this magnet is your third hand when reloading or changing pin sizes. The magnet is strong enough to hold a small clip of pins in place to avoid them falling or getting cock-eyed. Nice touch Milwaukee!

Tapered Tank Design

Looking at the top of the tool you’ll see that the nitrogen tank tapers, back toward the front. This keeps the business end of the tool narrower and more compact, allowing better maneuverability, something we appreciate in a finishing tool.

Non-Marring Tips

Another nice feature is the non-mar contact tips. The reserve tip is clipped on the rear of the magazine. If you look closely at it you’ll notice it is a “half” tip. The half tip takes an already nicely designed front end of the tool and makes the tip area more visible. The half-tip is for the carpenters that argue that the tip blocks their line of sight of the feed-lips. [the area where striker and pin feed-thru tool]

Depth of Drive

The M12 pin nailer has a tool-free depth of drive knob. This is something that I immediately noticed and appreciated since all of my pneumatic pinners needed an Allen wrench to move the nose back and forth. The depth knob is faster to dial in and obviously way easier.

Dryfire Lockout

The M12 pin nailer has a magazine reload indicator which I never seem to notice or look at. It does have a dry-fire lockout which is useful for preventing unnecessary holes in our workpieces.

Nitrogen Tank

The pin nailer’s cylinder has two parts that make up the tank: an inner cylinder and an outer cylinder. The space between those two cylinders is the area that is filled with Nitrogen. The striker & piston travel within the inner cylinder, using the pressure in the tank to provide driving power for the fastener.

There are two reasons Milwaukee uses nitrogen instead of compressed air, and limiting condensation is one of them.

  1. When the tool is filled, during manufacturing or service, they pull a vacuum so the tank is completely cleared. The tank is then filled with 99.9% nitrogen so there’s essentially no condensation in it. This could be done with air using a compressor that separates condensation/moisture out of the air, but it’s easier and more effective & repeatable to do this with pure 99.9% nitrogen
  2. Nitrogen also limits any seal permeation. Any sealed, pressurized vessel will experience some small level of permeation through the seals over time. Nitrogen permeates much slower than air. By using nitrogen, permeation can be kept so small that it would be many years (if ever) that a user/owner would ever experience degraded performance due to permeation 

This pin nailer comes with a 3-year warranty and was designed to provide a user 3-4 years of heavy use without the need for service. That should equate to 50 to 70k barads installed.


Runtime: This pin nailer can fire up to 750 pin nails, per charge, when equipped with a 1.5 Ah battery.

LED Light

In the past, I’d scoff at the idea of light on a nailer, especially a pinner. After using this on a project with mediocre lighting, I actually have to eat crow and admit that I really like this feature.

Using the Milwaukee M12 23 Gauge Pin Nailer

I used the M12 pin nailer in the shop building a cabinet to cover a stove hood and also on a cabinet crown molding installation project.

Besides the fact that this pinner is cordless and eliminates the hose, there are three things I like about this pin nailer:


Items like the depth or drive, magazine magnet, LED light show thought and care went into this design. They look at this tool, innovated it, and tried to eliminate pain points for the user.


It’s accurate! The double-action trigger and non-marring precision point tip provide sequential driving and accurate pin placement, with a great line of sight.


When I think of performance I’m thinking of size, weight, and power.  The M12 pinner is pretty close to my pneumatic nailer in size and punches pins into hardwood like nobody’s business. This nailer has the power to sink 23-gauge 1-3/8” pins sub-flush into Oak, Maple, and other hardwoods with ease. That is something that I’ve not seen in competitor pinners


The Milwaukee M12 Cordless 23 Gauge Pin Nailer 2540-21 sells for $249.00 as a kit at Ohio Power tool.

The Kit Includes:

  • M12 23 Gauge Pin Nailer,
  • M12 CP 1.5Ah Battery Pack,
  • M12TM Charger
  • Contractor bag

Overall Impression

This pinner now lives in a Packout shelf unit, in our van, with our other finish nailers.

At $249 as a kit, we think this is a worthwhile investment. If this nailer lasts 4 years when you amortize the cost that’s $62 bucks a year. What would you pay for no compressor and hose set up?

The overall impression is that this pinner is a win. Cordless, no hose, and the power to get the job done.

Milwaukee M12 Pin Nailer Video Review



About the author

Rob Robillard

Robert Robillard is a remodeler, general contractor, and principal of a carpentry and renovation business located in Concord, Massachusetts, and serves as the Editor of Tool Box Buzz and founding editor of A Concord Carpenter . Rob is in charge of our Tool and Product Review - Tool and Product Review - Video Channel, , where we post all of our tool reviews and video tutorials. Rob enjoys using his knowledge and experience to help and educate building professionals as well as DIYers on best practices in the remodeling industry. The Concord Carpenter's motto: "Well done is better than well said!" : Read more about Rob Robillard

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  1. FSP

    Will I break this gun shooting slight-head pins instead of headless?

    1. possibly – I wouldn’t do it

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