Milwaukee M12 Hackzall One-Handed Reciprocating Saw Review

The M12 (2420-20) model is a one-handed and cordless reciprocating saw introduced by Milwaukee.

It is the first in line in the 2420 series and is the lightest of the trio when comparing designs between each other.

If you don’t have too much time on your hands, you can have a skim through our overview of the Milwaukee M12 Hackzall below.

  • Compact and lightweight design at 2.2lbs and 11”
  • Powerful motor at 3,000 SPM and a ½” stroke length for smaller cutting jobs
  • Variable speed trigger included for increased control over cuts
  • Battery gauge shows you exactly how much time left until the next charge
  • Accepts both Sawzall and Hackzall blades

Features & Specifications

Let’s get stuck into it, and pick apart the features of this handy little reciprocating saw.

Firstly, we’ll be starting with the specs of the 2420-20 model.


  • Weight of 2.2lbs
  • 11” long
  • ½” stroke length
  • 3,000 SPM motor
  • QUIK-LOK Keyless blade clamp
  • Variable Speed Trigger
  • Built-in LED light for dark work spaces


Variable Speed Trigger

Variable speed triggers are standard across modern-day reciprocating saws, that’s a given.

What about the smaller, one-handed reciprocating saws, however?

Yep, those too.

With the Milwaukee 2420-20 model, a variable speed trigger is included. This is a vital addition, especially if you want complete control over every cut you make.

The variable speed trigger allows you to dictate the speed on your cuts, so you can cut different materials without having a set speed to do so with.

Stroke Length & Motor

It may be a small reciprocating saw in comparison to others, but don’t let that fool you.

The power the M12 packs it impressive when compared to its’ compact design.

With a 3,000 SPM motor, you won’t have to be worried about the power, with many buyers advising that they have had no issue in cutting through woods, pvc and drywall, to name a few examples.

Partnered with a ½” stroke length, the M12 will definitely have the ability to assist you with powering through materials, whatever they may be.

Keyless QUIK-LOK Blade Clamp Changes

With the Keyless QUICK-LOK blade clamp system, additional tools and keys to adjust and remove/insert blades are a thing of the past.

Changes can be made in seconds, not minutes – and as the M12 accepts both Hackzall and Sawzall blades, you can be content in knowing there are options available for you, without the compromise on time of your project when swapping between various blades.


As this review is looking at the reciprocating saw by itself, charger, batteries, and blades are to be bought separately.

What Puts The M12 Above The Opposition?

So we’ve had a look at the standard features of the M12, now let’s cast our eye over some of the features which place the Milwaukee tool above the others.

I picked three personal, stand-out features to discuss below.

Battery Fuel Gauge

I decided upon this feature purely for the convenience it provides when on the job. The battery fuel gauge allows you to see the juice left in the battery, which can give you the upper hand in tackling jobs.

Many people would say that preparation is key, and you should have your batteries charged at all times. However, it’s easy to get sidetracked by other tasks – and it’s even easier to forget.

I’m going to have a guess and say this has happened to you, too.

Have you ever had your saw cut off unexpectedly during a project because you thought you had charged it, or simply forgot to?

Then this is perfect for you.

Lightweight & Compact Design

The design of this one-handed reciprocating saw is, in my opinion, the premier feature of the tool.

This saw isn’t made for demolition jobs, that’s a given – but it can go in many spots that other reciprocating saws can’t.

At 11” wide and 2.2 lbs heavy, you’ll be able to get into positions and tight spots that a larger saw would have difficulties to do so.

It is also an important design in regards to ergonomics. As the saw is more compact than others and built for one-handed use, fatigue doesn’t play as much as a factor as it would for a heavier reciprocating saw.

You will be able to use the M12 in one hand, and use your free hand for leverage – which is the beauty of this design, giving more versatility to us customers.

That’s an added bonus, in my books.

Don’t you agree?

Accepts Both Hackzall & Sawzall Blades

Another great addition to the features list of the M12 is that this reciprocating saw accepts both Hackzall and Sawzall blades.

Many light-duty saws only accept Hackzall blades, which can prove costly if you have a heavy-duty saw – an additional out-of-pocket expense for you.

Yet, if you’re using this as a supplementary saw for lighter projects and work, you can use your alternative Sawzall blades on this tool.

This gives you more options, which really nails home the versatility of this saw that Milwaukee has included.

Final Thoughts

With its’ lightweight and compact design, you’ll be at ease knowing this can be brought anywhere with you, whether that’s from site to site, or simply within your garden for pruning purposes.

You won’t be using this cordless reciprocating saw for big projects, yet it will be a handy addition to your expanding set of tools.

You’ll be able to tackle a lot of jobs with the design, getting into positions you thought weren’t possible before. With a powerful motor and a handful of nifty features in the variable speed trigger, battery fuel gauge, and the keyless blade clamp – the Milwaukee M12 will surprise you.

I’d love to hear what you think about this model.

What jobs will you be using this saw for?

Leave your comments below.

James Thomas

James Thomas

Tool Enthusiast

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