Can Miter Saw Cut Thick Aluminum? | DeWalt Miter Saw Change Blade + Precision Setup

**tiger carpenter** · Mar 8, 2021, 12:50 PM

This video answers the question whether the miter saw (mitre saw) is capable of precisely cutting the thick aluminum (aluminium) stock.

DeWalt Miter Saw DWS780 XPS:
https://amzn.to/3brT5LV

Freud Aluminum Blade 120T Thin Kerf:
https://amzn.to/3ccsSjM

Square DIN875 Grade 00 INOX 75 x 50 mm:
https://amzn.to/2PNn1tF

I needed to cut a 2 inch x 2 inch x 2 inch (51 mm x 51 mm x 51 mm) aluminum cube for one of my projects.

I used the 2 inch x 2 inch solid aluminum square bar.

Because my project requires a high level of precision / accuracy, I was debating whether I should be using the miter saw for that cut. I used to make similar cuts on
the table saw and the cross cut sled, and I was overall happy with the table saw cuts in the past.

I will need to make many cross cuts in the thick solid aluminum stock in my future projects, and I thought I would give my miter saw a chance. It is much faster and easier for cross cutting after all.

My only concern was the precision of the miter saw crosscuts, as many people like to classify the miter saw as the contractor grade tool, and not suitable for the fine carpentry, where the high precision is desired.

I changed the blade to 120T carbide thin kerf DeWalt blade specialized for the aluminum cutting, and suitable for the fine finish of the cut surface.

I demonstrate in this video how to change the blade and use adapter ring for the blade to fit the 1 inch arbor size on the DeWalt miter saw, because believe me, it is not intuitive or easy at all. I had to use the adapter ring from 30 mm OD (outer diameter) to 25.4 = 1 inch ID (inner diameter).
I also showed in details how to setup the DeWalt miter saw, using just a good quality square (INOX DIN875 Grade 00), and obtain the best accuracy you can get out of it.

I showed how to:
1. make the table flush with the yellow insert (raised or lowered insert can lead to tilting your piece and disqualifying your cuts),
2. change the blade from 60T to 120T specialized for the aluminum fine finish cuts,
3. adjust 90 degrees between the table and the blade, using the super important blue thread locked bolt,
4. adjust 90 degrees between the fence and the blade, using stainless steel miter plate and indents (dents).

Finally, I demonstrated the actual cut of the thick aluminum (aluminium) stock. I used the stop block to get the desired length (I used the wooden scrap piece to setup the stop block to the perfect position giving me exactly 2 inches cut - not shown in the video to shorten it). I also clamped the material tightly, to avoid any movement due to the strong vibrations, while cutting the soft metals.

I measured the temperature of the cut face using the digital thermometer, and it was only 41 C = 105.8 F, which truly surprised me, as I was expecting the pece to be very hot, and was "cool" (normal) to touch (I live in tropics).

The weight of the 2 inch x 2 inch x 2 inch aluminum cube is 349.95 grams = 12. 344 oz.

The results were superb, I measured the length and it was perfectly 2.005 inches. I verified all 4 factory sides being perfectly square to my cutoff face. The cut face quality is very good, it can be further polished if needed, as it does show some radial saw blade marks.

The overall conclusions are: yes you can cut the thick solid aluminum stock on miter saw, and you can expect a very high precision results, should you have put effort in setting up your miter saw.

**FEM2008** · Mar 9, 2021, 11:32 PM

Thank for the great tips and demo.

I cut aluminum on a miter saw all the time. This year, I am coaching an FTC robotics team, and we use all kinds of aluminum channel, bar, and profiles. So I bought a 10" Hitachi miter and Freud 84T non-ferrous blade.

The first think I noticed is the plastic insert was not flush and flexed in some spots because there was gap between the shim and the frame. So I 3-D printed a shim to make it level with the top an added extra support. The saw blade was already spot on square withe table when checked with machinist square.

Some of the pieces I cut are small and there is large gap in the middle of the fence. This can very dangerous, as I cut pieces, the drop piece can fly violently and ricochet back into the blade. The other situation is, if the drop piece flexes as the blade is nearing the end of the cut, it can bind the blade solid and twist it with a really bad outcome (aluminum has a very high coefficient of friction with steel). The least damage is some broken blade teeth. Having something solid as a backer with minimal clearance around the blade is a must.
So I got a very nice and flat piece of wood and clamped to the back fence on both sides, then I cut through it, creating minimal blade clearance. My local hardware store has cabinet grade hardwood that is milled very flat and it worked perfect. Now, I can literally shave tiny slivers or cut washers out of aluminum tube without risking parts flying off or damaging anything.

The other hint is when cutting small pieces that cannot be practically clamped on both sides, is to keep the blade down after the cut is finished and until the blade comes to a stop. There is less chance of the blade marring the cut surfaces on the way up or catching the drop piece causing damage.

**tiger carpenter** · Mar 10, 2021, 05:54 AM

Thank you for your very good tips indeed.
Yes I had aluminum cut offs flying in the air in the past, and nobody would want to stand in their way, that's for sure.

Yes zero clearance insert is a must for small parts, and back fence too.