Choosing Table Saw Blades
Thoughts on table saw blade selection for cutting plywood and for ripping hardwood. March 26, 2010
Question
What is the best all around table saw blade to use to cut UV coated plywood? What type and brand for ripping hardwood?
Forum Responses
(Cabinetmaking Forum)
From contributor A:
If you want absolutely no backside tearout, I would highly recommend the Forrest Duraline HI/AT. We've had one on our small panel saw for a few years. We bought it specifically for two sided pre-finish. Glue line rip or fast ripping?
From the original questioner:
Can you get a clean cut on stiles and riles so you could skip the jointing process?
From contributor L:
Typical rip blades leave considerable "tooth" marks. Generally the fewer the teeth, the faster the cut. We've had good service from Leuco and FS. We tried a glue line rip blade on the table saw before we had a straight line saw, didn't work very well. Required more power than we had (5hp). We later used a glue line rip blade on our 10hp 12/14" table saw, 4 wheel power feed, better results but still not what we get from a straight line rip saw (15hp). We glue up panels right off the rip saw with better results than from the jointer. Glue line blades have taller teeth that sort of "plane" on their sides resulting in the requirement for more power. Going too slow causes heat problems.
From Gene Wengert, forum technical advisor:
When ripping, what part of the tooth actually touches and prepares the ripped surface? It is the sides of the tooth and not the top. The process of sharpening a rip blade that will make a surface that will be glued involves sharpening the sides of the teeth and also making sure that the sides all "stick out" the same amount to avoid a rough surface where you can see a multitude of teeth marks (called side dressing). It is surprising how often the rip blades are not properly sharpened and so people will say that they cannot glue off of a ripped edge. It should be obvious that a proper rip blade is suitable only for ripping. As indicated previously, if the teeth get dull, that generates heat and leads to a weak joint. Further, if there is not enough power, the slow feed also will result in heat and poor results. Feeding too slow for any reason also leads to poor results.
From contributor F:
I like the Forrest blades, the Hi-AT as previously mentioned works great on hardwood veneered ply and melamine also. For ripping I like the 30 tooth WWII.
From contributor W:
Many of your responses are good, but more related to solid wood. Keep in mind that the questioner is trying to rip plywood with a finish on both sides. This is more like a cross-cutting operation, since the grain runs in both directions and there is a finish on the bottom to be concerned with. A negative hook Hi-ATB or a hollow negative hook hollow ground blade are the best for this application.
From Gene Wengert, forum technical advisor:
A negative or zero hook angle blade on a table saw is asking for trouble. The wood will be kicked back. Avoid this absolutely, positively. Such a blade is desired (or essential) for a radial arm saw and for similar saws sometimes used for cutting large sheets of plywood where the saw moves and the wood is stationary. Note that the original question is how to cut plywood and the second question is ripping lumber. There is no question that rip saws for lumber must never use zero or negative hook.
From contributor W:
Ah, you are right on the second part of the question. I should have read that better. As to the kickback issue, you are right only if talking about small pieces. The kickback is caused by the negative hook trying to lift the part off the table. In panel products, the parts are larger and heavier. The mass of the part is enough to keep the part securely on the table. You also have enough surface area on the part to hold it down. These are the blades of choice in Europe where safety in the workplace is much more regulated than it is here.
From Gene Wengert, forum technical advisor:
Let's be practical. If I have a table saw and I put a zero hook blade on it to cut some plywood, will I always remember to change the blade back to a positive hook blade? Or will someone (or even me) bring a piece of wood that needs to be ripped or crosscut and forget what blade is installed? I would say that this is indeed very likely to happen. Also, the kickback is likely with lighter weight and with smaller pieces of plywood as well, as has been stated. Why even run the risk? A stationary saw should basically not use zero or negative hook saws.
From the original questioner:
Is there one blade that would do a good job on both? I am upgrading to a used pm66 5hp 3ph.
From contributor F:
As much as I value Gene's advice I have to disagree a bit here. Melamine and laminate blades use negative hook angles. So for those of us who are limited to tablesaws and still want to cut these products cleanly, a negative hook blade is it. These blades in a 10" size are generally either 60 or 80 tooth blades. If someone is going to try to rip solid wood with one of these blades, they have no business working with equipment in the first place. I would equate it with trying to drill a hole in steel with a Forstner bit, if you don't know better there's a problem.
Other materials a small one man shop like mine encounter occasionally that require 0 or negative hook angles on a tablesaw include solid surface, plastics, and non-ferrous metals (I do cut the occasional aluminum when needed).
To the last question yes and no. A top quality combination blade like a Forrest WWII or similar will make most cuts cleanly. However to get the most out of your blades it's better to have dedicated blades.
From Gene Wengert, forum technical advisor:
I did not mean to imply that a zero or negative was not the correct blade for the plywood in question. Rather, I wanted to state, and I think I did, the risk. Contributor F has certainly stated the issue well and having dedicated blades is indeed a correct solution. Unfortunately, accidents happen - guards are removed, kick-back devices are removed, blades are not checked before using, etc. Is the improved surface worth the risk?
From contributor L:
One of the problems with small shops is the reliance on a small set of tools that must be jack of all trades. Table saws fall into that category. Given the proper setup they can do ok on a wide variety of work, true, not as good as tools designed/optimized for a particular function but ok. The killer here is taking the time to set the tool up properly for the job at hand. Most people will take risky short cuts rather than change blades, use guards, use (often very poor) riving knives/anti-kick backs, change throat plates, put the power feed on, or even worse use the saw with a “molder” head and no powerfeed.
We’ve never had a bad accident in our shop but I’ve seen all of the above practices by people that should know better. My solution, training, but I’ve found that “knowing” and doing are two entirely unrelated things. So the next best I could do was buying a SawStop table saw.
