Tool Box Buzz

Greenworks 12-Inch Cut-Off Saw [Power Cutter]

We recently looked at the Greenworks 12-Inch Cut-Off Saw . The 12-inch Greenworks cutter is powered by an 82V 3.2kW battery platform. The beauty of a battery power cutter set up like the Greenworks is all you have to do is insert a battery and start cutting. There is no pull start, 50:1 gas ratio, spark plug, stale fuel or clogged air filters.

Greenworks currently is offering 4 battery sizes, we tested our unit with w 4.0 Ah battery.

Greenworks Cut-Off Saw | Specifications

• Volts: 82V
• Motor: Brushless
• Performance: 3.2kw
• Cutting Speed: 5248 RPM
• Torque: 5.2Nm
• Blade Diameter: 12″
• Blade Arbor Size: 1″/20mm
• Electronic ON/OFF: Yes
• Integrated LED: Yes
• Cut Depth: 4.3″
• Blade Speed: (F/S) 279
• Speed Settings: Variable
• Water Connection: Yes
• Adjustable Flow :Yes
• Adjustable Guard: Yes
• Guard Material: Magnesium
• Aux Handle Material: Metal
• Overmold Grip: 1/20mm
• IP Rating: IPX4
• Sound at Ear: 94 (dBa)
• Vibration Aux: 3.99 (m/s)
• Vibration Rear Handle: 2 (m/s)

First Impression | Greenworks 12-Inch Cut-Off Saw

The Greenworks 12-Inch Cut-Off Saw is a brushless, direct drive, zero- emission power cutter that allows users to work indoors without the worry fumes. It is compact and seemingly well built. This 82 volt cutter has a 4.3″ depth of cut and is lightweight and well balanced.

The LED light on the blade guard is a nice feature, we wondered, due to its proximity to the blade if slurry splatter would build up and obscure the LED during our testing. It did not!

Operating the saw is simple and intuitive with an electronic power button, safety switch and trigger.  This two-step process to turn on and off the tool is easy to follow and we liked the simplicity of it.

Testing the Greenworks 12-Inch Cut-Off Saw

The cutter has a deeper cut than other competitor 12″ gas saws, 4.3 vs 3.9 inches, and we liked that the 4.0 Ah battery charges in 30-minutes. We tested the Greenworks 12-Inch Cut-Off Saw in several materials: concrete with embedded rebar, metal pipe and rebar.

Metal Cutting Test

Outfitted with a fresh battery and abrasive cutting disk we used the Greenworks cutter to cut metal pipe, and five #4 ganged rebar. The cutter made fast cuts and was easy to use. 

Concrete Test Blocks

We poured 3500 psi concrete blocks, 12” x 24” x 4.5″ deep for a Head-to-Head test we were working on, so it made sense to use the same blocks to test the Greenworks concrete cutter. Each concrete block also had two embedded #4 rebar running along its length.

Note – the Greenworks cutter was not able to cut all the way through our test blocks. We maxed the cutter out for cutting and counted the slices completed.

Performance Testing | Concrete with Embedded Rebar Cutting [Ave. Speed]

Run-time on cordless concrete cutters is important when discussing how battery and gas operate differently.  The number one question we are asked is,  “How do this saw compare to a gas power cutter? In order for us to address this question we included the Husqvarna K770 gas saw as a comparison.

Run-time Test Procedure:

Without a test rig to eliminate these types of variables, it is very hard to have a controlled test. Technique is important and we recognize that we needed to let the tool do the work and not bog it down, which is why we designed our tests with the following criteria:

1. The Greenworks had two fresh batteries and new diamond cutting blade
2. The Husqvarna K770 had a full tank of gas and a fresh Milwaukee Diamond blade
3. 4 operators per saw.
4. We used the 24″x12″x4.5″ concrete test blocks
5. Each cut is timed and recorded.
6. Water was used on each cut
7. Each operator will make 3 cuts and swap out to prevent fatigue. [Fatigued users tend to lean on the saw]
8. Every operator will employ a “stepped” cutting method.
9. Every operator will let the tool do the cutting, and listen to the motor. Operators could apply pressure if the tool would allow it, and if the motors seem like its bogging down they were to let up on the pressure.
10. The test ended when the saw battery died, and when the K770 ran out of gas
11. The total slices [including partial cuts] were recorded for a total lineal foot measurement.

Note on Run-time Testing

With any power cutter you will experience varying results based on the material you’re cutting, you’re cutting style, operator experience, blade used, etc.  Ambient temperature also affects run-time. The more demand you put on the motor, for example leaning into the saw too much, the more Amps it will pull from the battery to keep the power output. The same effect can happen with a gas saw, except runtime is just not usually taken into consideration given the quicker refueling vs. recharging time.

Cutting Results | Greenworks 12-Inch Cut-Off Saw

We made 14 cuts in concrete [14-lineal feet] before draining both batteries. The Husqvarna K770 gas saw completed 30 cuts/feet and was able to cut completely through the test blocks. We recognize that we were cutting with a 4.o Ah battery and had we had the 8.0 Ah battery to test we probably would have had 28+ cuts. and be much closer the the K770 saw.

We did notice that the Greenworks 12-Inch Cut-Off Saw if pushed too hard can be bogged down and it was important to let this tool do the work and not bear down too hard.

The reality is that with two batteries, the Greenworks cut-off saw can compete with a gas saw.

Improvements

If we were to offer Greenworks advice on improving their saw, it would be the water connection. The saw has a flexible water hose which makes one-handed hose connecting impossible. We recommend that the water connect be mounted to the side of the saw as a solid connection.

Price and Where To Buy

The Greenworks 82 volt power cutter costs $439.99 as a bare tool, and $699.99 as a kit. The kit includes:

• 82V 12″ 2.5KW Power Cutter – 82PC12
• 12″ Diamond Blade
• 4Ah Battery
• Charger

I included the Greenworks graphic below because it tells an interesting story comparing cost of ownership between the Greenworks saw and a gas power cutter.

Final Thoughts

We enjoyed using the Greenworks concrete cutter and all agreed when paired with a 4.0 Ah battery its best suited for lighter masonry work such as cutting pavers. If you plan on cutting basement slabs open, or doing any full depth concrete cutting, then we recommend pairing it with an 8.0 Ah battery.

We think that battery power cutters have their place, especially when remodeling indoors. It’s our opinion that contractors who cut concrete with 2 tanks of gas or less a day are in the “sweet-spot” to convert to a battery power cutter.  If you are cutting all-day and using 5 to 7 tanks of gas you should stay with a gas cutter or invest in more batteries.

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