Milwaukee M12 Cordless Jig Saw Kit

A capable jigsaw with a good array of features


Milwaukee M12 Cordless Jig Saw Kit

Milwaukee has extended their line of compact 12-volt power tools with the introduction of a compact jigsaw, which comes as a bare tool (2445-20, no battery) or in the kit form (2445-21) that we'll look at here.

The Milwaukee M12 Cordless jigsaw Kit (2445-21) consists of the jigsaw body (2445-20), one M12 lithium-ion battery (48-11-2401), a 30-minute charger (48-59-2401), an anti-splintering insert (43-84-020), a non-marring shoe (31-15-1600), a 10 TPI blade, and a canvas carry case.

Milwaukee 12V tools now ship with the newly re-designed 'Red Lithium' battery. These batteries are externally identical to the older 12V batteries. However, according to Milwaukee, due to changes in cell construction and chemistry, the new Red Lithium batteries offer 40% more run-time, 20% more power, and 50% more recharges than conventional lithium-ion batteries. You can expect about 1,500 charge/discharge cycles from the batteries.

12 Volt, 1.5 Ah lithium-ion battery
12 Volt, 3 Ah lithium-ion battery
The 2445-21 kit ships with one 12V, 1.5 Ah (Amp-hour) battery. As with all 12V batteries, the nominal voltage under load is 10.8V. Once you begin using the battery, the voltage (i.e. the electrical power) is going to remain fairly constant, while the capacity (Amp-hours) will gradually decrease. Which is why lithium-ion powered tools run at full power until the stored energy is depleted.

Sophisticated electronic circuitry inside the battery and the tool body enables them to communicate with each other to control the energy discharge. This prevents the battery from being discharged beyond safe limits.

At only 6 ounces the battery adds very little weight to the jigsaw. An extra battery cost $45.99 CA ($31.99 US). If you already have Milwaukee 12V tools you can swap batteries around; however, if this is your first Milwaukee cordless tool, it's a good idea to purchase a spare battery. There is nothing worse than running out of power half way through a job, and having to wait while the battery recharges.

If you'd like to have a longer run-time, and don't mind some extra weight (14 ounces) and a longer recharge time (60 minutes), then you might want to purchase the optional 3 Ah 'M12 XC High Capacity Red Lithium' battery (48-11-2402), priced at $77.44 CA ($69 US).

12 Volt diagnostic charger
Canvas tote bag
The diagnostic charger that comes with this kit will recharge the new Red Lithium or older lithium-ion batteries. The charger has built-in circuitry that interfaces with electronic circuitry in the battery to control energy charging. This prevents the battery from being charged beyond safe limits. While you typically recharge only after the battery has run out of its charge, you can top up the battery at any time without adversely affecting its life cycle.

Most cordless tools come with a storage bag - some are barely useful, while other, like this Milwaukee tote bag, are highly functional. The bag has ample room to store the jigsaw, charger and battery, along with a second battery and a supply of blades. Additionally, there are six side pockets in which you can store a range of accessories - tape measure, drill bits, small hand tools and the like.

On-board battery fuel gauge and trigger lock switch
Whenever you press the variable speed trigger two things happen. The on-board battery fuel gauge lights up to let you know how much battery life remains, and the work light comes on. The fuel gauge turns off after a few seconds. I find fuel gauges very useful - it enables me to quickly check battery status before heading out to a job site, and either grab a couple of charged batteries, or top up the batteries before I hit the road.

Bright LED work light and wire frame safety guard
The LED work light isn't always needed, but can be a very welcome feature in poor lighting, as the light is very bright, and it does a good job illuminating the cut line. Even though it's constantly on while the trigger is depressed, it consumes very little current.

Smooth, removable shoe protects delicate surfaces
I like the removable shoe on the 2445-20 as its smooth surface protects pre-finished ply, laminates, or sanded wood surfaces from scratches. To conserve the shoe and maintain it's smooth surface I remove the shoe when cutting rough stock. You can purchase a replacement from Milwaukee. 

The 2445-20 lacks both an air blower and a port to connect the tool to a shop-vac. Both features are handy if you do a lot of sawing with a jigsaw. Their absence isn't an important consideration for me, as I use a jigsaw occasionally - to cut sink holes in countertops and to cut curves in sheet goods or solid wood when I can't make the cuts on a bandsaw.

Anti-splintering insert
Jigsaw blades cut on the up stroke, and any tear out occurs on the top side of the material you're cutting. An anti-splintering insert - a small block of plastic that surrounds the blade - acts much like a zero clearance insert on a table saw, helping to reduce splintering as the blade rises through the stock. The anti-splintering insert on the 2445-20 is clear, which makes it somewhat easier to see where your cutting. It's also replaceable should it become damaged.

While anti-splintering inserts are helpful in reducing splintering, particularly plywood and melamine, they don't eliminate it. You also want to use the right blade for the type and thickness of material you're cutting. The 10-TPI blade that comes with the 2445-21 kit is fine for general cutting. But for fine, near-splinter free cuts a 20-TPI blade is a better choice. There are also blades designed to cut on the down stroke, which work well on laminate. If you use a down stroke blade exercise a bit of caution, as the saw is more likely to push upwards and jump about. To counteract this movement use a firm grip and apply steady downward pressure. In any event, jigsaw blades aren't overly expensive, so it's a good idea to keep a selection of blades on hand - for general purpose cutting, fine cuts in plywood, soft metal, and plastics.

45° bevel capacity both left and right
The 2445-20 features a tool-free bevel adjustment that works great. Pus a bevel release and simply tilt the head left or right. You can bevel the head up to 45° to either side. The scale is reasonably easy to read.

90° positive lock
There is a positive lock at 90°. I made cuts at both 30° and 45°, and found them to be quite accurate. Once the bevel lock is applied the head locks securely in place.

The blade is square to the base
I'm all for tool-free blade change, and on the 2445-20 it works like a charm. Push a spring loaded blade tension lever, insert a blade into the plunger, and then release the lever. Pretty simple. To change blades you simply repeat the process, but you don't have to manually pull the blade out - a spring pops the blade out of the plunger. This is a nice feature as blades can get very hot in use.

A support roller helps keep the blade running straight
Right behind the blade is a support roller that helps prevents the blade from moving backwards under pressure, and probably provides a bit of lateral support. This helps keep the blade running straight when cutting, particularly in thick stock.

The 2445-20 has trigger controlled variable speed, with a range of 0 to 2,800 SPM (strokes per minute). This is comparable with most other cordless jigsaws. I would like to have seen a speed dial, which makes it easier to control speed rather than relying solely on trigger pressure. The 3/4" stroke is best suited for cutting thinner stock - sheet goods and 4/4 solid wood. 

Even with a short stroke I found the saw cut quickly. On a full charge I cut an average of 192 linear inches (16 feet) of 3/4" plywood - which is not too shabby. With the 3 Ah battery you could expect to cut double the length. I was also able to make 22 crosscuts in 1-1/2" x 2" birch on a single charge. 

As you see in the photos below, crosscuts made with a 10 TPI blade are fairly rough on the top side; but on the bottom side the cuts are very clean. Whenever possible make cuts with the good side down; otherwise, if you want cleaner cuts choose a premium blade.

I was pleasantly surprised at how comfortable the 2445-20 was in use and how little vibration the saw generated. Noise level is comparable to other cordless saws I've tried.

Typical crosscut with a 10 TPI blade on 3/4" pine

Reverse side has a much cleaner cut

You'll get somewhat cleaner cuts when ripping or cutting curves
At just over 4 pounds with the battery installed, the 2445-20 is light, and well balanced. I found the saw very easy to control one-handed. The motor housing is padded and serves as an auxiliary handle.

Furniture makes, finish carpenters, hobbyist woodworkers and avid DIYers will find the 2445-20 a very capable jigsaw. It has a good array of features, is light and easy to use, has ample power for cutting a range of sheet goods and solid stock up to about 1" thick, and a generous 5-year warranty.
  • 12-Volt, 1.5 Ah lithium-ion battery 
  • 0-2,800 SPM 
  • 3/4" stroke length 
  • 45° bevel capacity, left and right 
  • 90° positive lock 
  • Uses T-shank blades 
  • Tool-free bevel adjustment
  • Tool-free blade change 
  • LED work light 
  • Trigger lock 
  • On-board battery fuel gauge 
  • 3" W x 7-1/8 H x 8-7/8" L) 
  • 3 lb 13 oz (no battery)
4 lb 1 oz (with battery) 
  • 5 year warranty 
  • jigsaw body (2445-20); 
  • M12 battery (48-11-2401); 
  • 30-minute charger (48-59-2401); 
  • anti-splintering insert; 
  • non-marring shoe;
  • 10 TPI blade; 
  • carry case 
MANUFACTURER:Milwaukee Electric Tool Corp
AVAILABLE AT:Tool and equipment suppliers nationwide
Carl Duguay, February 2011 
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