Thin kerf blades?

[noxpurt]

Im looking for a 2nd blade for my Dewalt 12" miter saw that I have been using for 12 years. Thought Id get a blade to have while one is being sharpened.

Seems like most blades now are the thin kerf. Any reason not to use those? Current blade is .125 carbide. I wondering if the thin blades tend to wander more. I dont care about saving material in the cut. Dewalt has a 2 blade pack that is good price but they are thin kerf. can you recommend a good all purpose carbide tip blade?

thanks for any tip!

[Leon]

Yes, thin kerf blades come on saws that are under powered. They are more likely to gice you a non flat surface.

Yes, and they flex more.

I dont care about saving material in the cut.

Good, 1/32" savings per cut is basically worthless.

Dewalt has a 2

Forrest.

[Joe]

I am using Freud and am very happy with the performance. They provide a lot of good info on the site. Here is the URL-

[Teamcasa]

Pass on the thin kerf blades. - For all the reasons Leon gave. Get a Ridge Carbide 1st choice - Forrest 2nd choice and other than custom made blades, pass on the rest.

Dave

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[Guess who]

I've been using one for years on the TS. The B&D hand saw, standard blade, finally started making noises, so I bought a Makita which came with a thin kerf blade. I still can't believe how easily it slices through oak. There's simply less resistance, and I was taught early on by my father to let the tool do the work, so I don't force anything, just a steady guide. I'd have to look up the blade name since it's a recent purchase. It might say something in their website.

[bdeditch]

[president]

The outside of a saw blade runs faster than the inside, same rpm but different mph. This means the blade wants to cup. The bigger the diameter and the thinner the steel the more tendency there is to cup.

In addition each blade has its own harmonic properties. At "critical speed" the blade will flutter. Then it will double flutter.

Anyway, not only is a big, thin blade easier to move but it also has a greater tendency to move on its own.

This also means that it will be much less tolerant of fluctuations in the equipment as well.

Tom

[edswoods.1]

In a perfect world saw blades wouldn't dull. It's when they do that overheating and distortion happens, and a thicker blade holds out a litte longer maybe, but other than that they cut about the same, and are a little bit easier on the saw.

[Andrew Barss]

[e-mail] wrote: : The outside of a saw blade runs faster than the inside, same rpm but : different mph. This means the blade wants to cup.

I don't see how this could be right.

If the blade is flat when it starts up, even if the differential speed were to make it "want t cup", wouldn't the firces on each side equalize?

By the same token, if you were to mount a rod perpendicular to a rotating shaft, the rod would want to bend because the tip would be travelling faster than the part nearer the sghaft. What direction would it want to bend in?

-- Andy Barss

[Patriarch]

Andrew Barss wrote in news:e3dgj3$er5$2 @onion.ccit.arizona.edu:

Now take you rotating disk, and run the edge through 8/4 oak. What heats up and expands first? Assume the disk isn't as sharp or as clean as it might be...

Patriarch

[Leon]

Eventually thay will, however I see the blade wobble on my both of my Forrest blades as they come up to speed and then smooth out and cut quite smoothly.

With more resistance, it would bend back.

[Mike Dembroge]

I have a Dewalt 12" saw and use a Forrest Chop Master and use that almost exclusively for woodworking. I recently did a 2-room addition, so I bought a Dewalt 2-pack of thin-kerf blades rather than use the Chop Master on 2x material. I was amazed at how much the blades flex when cutting 2x material. Of course, since accuracy is less important doing construction than woodworking, I probably tended to bear down on the saw more, but still, I could see the blade flexing on some fo the cuts.

For woodworking, and the like, I'd stick with full-kerf blades and take your time with the cuts. Thin-kerf is probably okay for less finicky work.

Mike

[president]

This saw plate bending is not an obvious phenomenon.

Andrew Barss is correct in identifying the most important pressures on the saw blade. However, as those forces are equalized, and the blade gets thinner and is run faster and fed faster other, more minor pressures, start to become more important.

Sawyers have been seeing plate bend for years due to cutting pressures. "Self Bending" plate came as a surprise as saw blades got much thinner. The forces on each side are roughly equal but the plate wants to cup due to forces from the outside in. You are correct that it could bend either way.

Think about a 30" mill saw that is 0.070" thick. What they do on these blades is to use pressure rollers to roll compressed bands on one side of the saw blade to prevent cupping. This is called tensioning and compensates for the tension created during running. (Freeborn covers this briefly on p. 25. If you don't have his book I can email a copy free.)

This issue is not fully understood. It is an important part of the Wood Machining Institute Seminars annually. In addition Forintek (Canadian Forest Industries Technology) continues to do work on the matter.

Anyway, the point is that thin kerf saw plate bends more easily due to outside forces but also wants to bend on its own.

1" bore 12" diameter C = pi x diameter Bore has about a 3 inch diameter Rim has about a 36" diameter At 10,000 rpm the bore edge is moving app. 6 mph The cutting edge is moving 70 mph

Tom.

P.s. The Freeborn Carbide Saw manual is free. Lowell wrote it and let me put it on the web. there is no fee and you aren't on any mailing list. Just email for a copy.

[Tex]

... snipped

Unless I need to cut something at the full height of the blade I always run a stabilizer plate between the blade and the nut washer (the fence side of blade). It definitely keeps the blade more stable but I wonder if it matters which side of the blade it is mounted on. Hmmm ...

[Guess who]

I think you mean Circumference in the last two statements.

It's more like 9.9 [let's say 10] mph, and 120 mph ...same principles apply though.

Stress is cause by forces trying to overcome inertia, and a thin-kerf blade does have less mass.

Is it not possible to simply make it available for download? Why ask for an email address at all?

[president]

Mostly because i am old and forget things. I forgot that we put it up on the web.

Try

I should have said circumference.

Thank you, tom

[Guess who]

Glad to help. I'm getting there too in years, but not in attitude. :)