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Reply by DavidNJ

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Posted on What is the Best Blade for Cutting MDF on a Table Saw?

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DavidNJ

384 posts in 498 days


#1 posted 455 days ago

I talked with Freud and Amana on the phone.

Freud recommended the LU80, a Hi-ATB 80T labeled Ultimate Plywood/Melamine. The catalog shows a 2° hook, the person on the phone said it had a -2° and the catalog was in error. I questioned the wear on a Hi-ATB in MDF, and he suggested the LU98, a TCG 80T with a 5° hook. It is labeled Single Sided Laminates.

Amana suggested an 80T TCG with a 10° hook. They were pretty definitive: a Hi-ATB will wear too quickly and he wanted the hook to cut into the material, not unlike a ripping blade (which typically has a 20° hook). The person at Amana said that for materials with long fibers—wood, plywood, veneers—a Hi-ATB or ATB produces a clean cut. He continued that manmade materials with a uniform composition didn’t need that and would work best with a TCG tooth pattern. That makes sense.He also said the difference between the Amana line and their A.G.E. line was limited to the anti-vibration method: the Amana has copper inserts while the A.G.E. uses laser cut patterns.

I also found a 1994 Fine Woodworking article on MDF. That article said:

“Sawing—-A 50-tooth combination blade is suggested for rough-cutting large sections of MDF on the tablesaw. But I make so many things out of cutoff pieces that I go right to my finish-cut blade. That used to be a 60-tooth triple-chip. I loved that blade; with a pair of hold-downs and my pride and joy, shopmade, European-style adjustable splitter, a piece of MDF would slide down the fence and exit the blade with a new edge so smooth that I had to stroke it. Then I bought the other blade manufacturers recommended for MDF, a 60-tooth thin-kerf alternate top bevel (mine is a Freud TFLU88). It seemed to cut even cleaner than the triple-chip, and material moved more easily through the blade because of its semi-thin kerf (nominally .090-in.). Its teeth angles fit the NPA’s specs for a blade to saw cleanly top and bottom surfaces of overlaid panels. They are a 15° hook, 15° top bevel and a 10° alternate
face bevel.

“I use 6-in. blade stiffeners for a slightly finer cut, and I made a zero-clearance insert to keep the dust down where it belongs. I’ll talk more about MDF dust problems and solutions later.

“My friends in the cabinet shop have good results using the tablesaw to kerf MDF sheets, so they can be bent into curved forms, as shown in the photo at right.”

The LU88 is a vanilla ATB crosscut blade, and inline with Freud’s Hi-ATB recommendation.

Freud has three blades labeled for laminate, melamine, and other manmade materials. One is a full kerf blade for single sided materials. The others are a full kerf and a thin kerf for double sided materials. All three are TCG designs. Where they differ is in the hook angle. The single side blade has a 5° hook. The double sided has a -3° hook. That begs the question: is a negative hook necessary to avoid chipping (the manmade material equivalent of tearout?) on the bottom side?

The Solid Surface blades have a similar TCG and a 0° hook. The differences look small, pretty much limited to the hook. What other difference could there be?

Freud uses different composition teeth on their blades. The LU80 recommended by Freud is not as hard as the blade for laminates, melamine, and solid surfaces. In the chart below they indicate their Specialty and Super teeth are the same composition. Wouldn’t the harder teeth, described as “Super Hi-Density Tungsten Carbide – half the size of micro-grain carbide (.4 microns vs. .8 microns) making this carbide the hardest of all to withstand abrasive material and create swirl-free finishes.”

It would seem the selection hinges on hook angle and tooth composition. It seems that hook angle affects the speed and quality of the cut which may be readily observable. It also seems the tooth composition would affect longevity which would be harder to measure.


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