How high should the blade be on my TS be?

[Joe Chritz]

Interesting response from Freud. That makes perfect sense that the blade manufacturers would design the teeth to hit and the correct angle at a specific height.

Joe

[Richard Dragin]

I was taught the rule of thumb is raise the blade as high as the amount of thumb you want to cut off.

[J. Z. Guest]

Higher Blade = Less teeth in the wood at a given time = cooler teeth with less burnt pitch on their sides. There will be more tearout in the bottom of the workpiece. A higher blade height is more dangerous because there is more blade exposed to hurt you in the event of an accident. Lastly, a high blade is more likely to be a factor in kickback because the rear of the blade tends to lift the workpiece up.

Lower Blade = More effort from the saw, due to the teeth being in the workpiece nearly the whole top arc of the blade. But cleaner cuts on the bottom of the workpieces, and less chance of kickback because the rear of the blade is not trying to lift the workpiece. Once the workpiece is lifted, it doesn't take more for it to be "caught" and thrown at you by a sharp, carbide tooth. More chance of burning the wood with a lower blade, since the teeth are in the wood through the whole top arc of the blade rotation.

For me, the bottom line is to have the blade high enough so the full tooth clears the workpiece and a bit more. If I'm experiencing burning even though I know everything is lined-up, I can raise the blade. Ditto if the saw seems to be bogging. But I'm damn careful then; always use featherboards and a hold-down shoe while feeding the workpiece.

[Nissim Avrahami]

I went to the garage and took a few pics.

This is the blade height (base of the gullet) for 3/4" thick wood.
Please note the angle of attack.
01.jpg

And this the "correct" blade height for 1¼" thick wood.
Please note the angle of attack.
02.jpg

And this is the "correct" blade height for 3" thick wood.
Please note the angle of attack.
03.jpg

So, what is the difference if the blade is set for 3" thick wood but, I'm cutting only 1¼" or 3/4" thick wood...I mean, I will get the same tear-out in all the 3 cases.
04.jpg

Is the saw blade makers are actually telling me that "our blade has the minimum tear-out only for 3/4" thick wood (or maybe for 1" or 2" or 3") but, cannot give a tear-free cut for any thickness" (up to the blade height limit).

On the Band-saw, the angle of attack is one for any wood thickness but on circular saw blade, the angle of attack will change, depends on the blade height.

Oh, and I don't see any danger of setting the blade at "full height" for 3" thick wood or 3/4" thick wood....if the blade guard is installed of course....
06.jpg

[Rich Engelhardt]

Hello,
Dumb question but wouldn't the hook angle be a big factor?
I have a couple of blades (10") that are labeled for table saw/miter saw.
I know from previous threads here that a negative angle is preferred on the miter saw, whereas a positive angle is desired on the TS. ( IIRC - and please correct me if wrong).

I'm too lazy right now - plus I'm in my bare feet and the garage is freezing cold - to run out there and grab one to see exactly how much rake there is.

Wouldn't a blade w/out a positive rake need to be used higher ?

Oh- and FWIW - I read a recent article that said the gullet should be clear of the work to prevent sawdust from jamming it.

[Cliff Rohrabacher]

Very little. Letting it stick up a lot causes it to fling crap at me.

[Tom Veatch]

... I read a recent article that said the gullet should be clear of the work to prevent sawdust from jamming it.

Hmmmm, sounds like an urban legend to me.

Considering a table saw, no matter how much of the gullet is above the work at the top of the blade's arc, the gullet is completely buried during the time the tooth is creating the sawdust. If the gullet size and feed rate is such that the gullet will become dust packed, I don't understand how exposing the gullet before the dust is ever created will correct the problem.

And what about those cuts that don't completely penetrate the work?

I'm afraid I'm going to have to be respectfully skeptical of that article's position.

[Michael O'Sullivan]

One point on safety is that the higher the blade is, the easier it is to see. Also, there is a lot less blade hidden within the workpiece. In other words, if the blade is lower, it is easier to get your fingers close to the blade without realizing it.

[Mark Singer]

This is a good question. If the blade is just above the wood most of the kick is toward the operator. Not much of an issue on big boards or if you use Board Buddies. Otherwise that can be minimized by the full gullet above which is a good overall rule of thumb