Clarification needed, what is thin kerf ???

[Shawn Honeychurch]

Hey all;

Well based on a past thread about my small (1 hp) tablesaw, I took the advice and when out and bought a thin-kerf, 20 tooth, carbide tipped, 10" DeWalt blade for ripping.

Got it home, installed it and ripped a piece of 2x4x8', when beautifully, like a hot knife through butter. WOW, what a difference, did it in one pass and no burning, used to take at least 2 passes and there was lots of burning.

Then I decided to see just how thin it was, took off the blade and compared it to my others, a regular 24 tooth DeWalt and a 60 tooth Oldham finishing blade. Imagine my surprise, no difference in thickness at all. All three of them are exactly the same except for tooth count. :eek:

So, what the heck, if thin kerf is not the thickness of the blade or the tips, then what is it?

Shawn

[Dewey Torres]

Thin kerf refers width of the teeth on the blade which determines the kerf 1/8 inch or less. I think what you may have experienced is a sharper and newer, possibly higher quality saw blade.

[John Lucas]

Shawn,
All I can suggest is : 1) you have thin kerf on all your blades...I think of it being 1/8" kerf.and regular being about 3/16; 2)I think there is greater probability that old blades needing cleaning and sharpening AND they werent designed for ripping...very important last point. Years ago I thought I could use any one of my Forrest blades for all things. Then I had a hunk of maple to rip and I only burned and had to stop. Bought a rather inexpensive rip and it cut like butter. Now I use only the less expensive blades...a CMT thin kerf for ripping, and an a 80 tooth cabinetmakers blade.

[Jamie Buxton]

The standard kerf is .125". Thin kerf is anything less. In 10" tablesaw blades thin kerf is almost always .1". In 7 1/4" blades (for handheld circular saws) it is more like .05", but varies a bit from manufacturer to manufacturer.

[Frank Drew]

Shawn,

Thick or thin kerf is also determined by how much set the teeth have, in simple terms how much the teeth stick out on both sides of the blade. So two saw blades can have the same thickness plate, and individual teeth the same thickness, but one will cut a narrower kerf if the set is less.

Can't have too little set, though, or else the blade will bind in the cut; it's got to be at least a certain amount more than the blade thickness (the same principle applies to hand saws).

[Rod Sheridan]

Hi Shawn, in a 10 inch blade;

- standard kerf is 3.2mm or aprox. .126"

- thin kerf is 2.3/2.4mm or aprox. .094"

and it refers to the kerf dimension in the wood.

As you probably found out by accident, ripping and cross cutting requires substantially different number of teeth and profiles.

In general;

- rip blades, aproximately 24 teeth, flat top grind, very deep gullets. When you rip, the grain of the wood is in the same direction as the cut, and the chips come out like long shavings, hence the deep gullets.

- cross cut has alternately bevelled teeth to shear the wood fibres at right angles to the grain. The chips look like dust, many teeth, (60 to 120) with shallow gullets.

A narrow kerf blade removes less wood, so it requires less horsepower to cut. The downside is, they aren't as stiff as a full thickness blade, and the vibration may result in a poorer quality cut.

Note that you can only reduce the feed rate so far, since the chips cool the blade teeth. So with a smaller powered saw, you may need a thin kerf blade to cut fast enough to have the chips cool the teeth.

I suggest that you check for industrial saw suppliers in your area, you can often purchase industrial grade blades for the same prices as homeowner blades from other stores. (You may not get fancy packaging however).

Regards, Rod.

[Shawn Honeychurch]

Hmm, lots of good info here.

I will have to take a closer look at the blades, I was only looking and plate thickness. I did not think to look at the set of the teeth.

I have been learning about different blades for different uses, this new blade is fantastic for ripping, and my 24 tooth is great for cross cuts, I save the 60 tooth blade for when I want really clean cuts for for mdf.

Seeing how much easier it cuts like this I think I will go looking for an 8 1/2" blade, 20 tooth for my DeWalt RAS.

Rod, why industrial blades??

Shawn

[Clifford Mescher]

Shawn,
All I can suggest is : 1) you have thin kerf on all your blades...I think of it being 1/8" kerf.and regular being about 3/16; 2)I think there is greater probability that old blades needing cleaning and sharpening AND they werent designed for ripping...very important last point. Years ago I thought I could use any one of my Forrest blades for all things. Then I had a hunk of maple to rip and I only burned and had to stop. Bought a rather inexpensive rip and it cut like butter. Now I use only the less expensive blades...a CMT thin kerf for ripping, and an a 80 tooth cabinetmakers blade.
John, I'm sure you meant to type 3/32? Clifford

[Rod Sheridan]

Hi Shawn, I purchase my saw blades from an industrial saw supplier because I find that their product works better than the blades you get at most other stores, and their cost is reasonable.

In addition they can sharpen blades, and custom grind them for particular operations.

regards, Rod.

[Howard Acheson]

>> I was only looking and plate thickness.

Plate thickness is irrelevent. If all your blades are carbide tipped, just measure the thickness of the carbide tooth. You should find, as already said, that standard tip width is about .125" and a thin kerf blade is about 0.95 - 0.100". "Set" is only used on old time steel blades.