Flat bottom saw blade question??????

[Matthew Curtis]

Are these blades that provide a flat bottom cut like the Forrest Woodworker II 10" 40T #1 Grind Saw Blade good for use as a combination blade. Will they do a good job with general rip cuts and crosscuts where a flat bottom is not required? What other options are there for flat bottom producing saw blades? I have only seen the Forrest blade. Does Freud make one?

[scott spencer]

The only grind that will provide a true flat bottom is a flat top grind (FTG), which are most commonly found in dedicated ripping blades. Most combo blades that offer a "flatter" bottom are a combination grind of ATB and FTG teeth, where the ATB teeth actually protrude slightly above the FTG teeth, which in turn leaves slight bat ears at the outside edge of the cut. FTG blades are known for their ripping efficiency, but they'll have more tearout for crosscuts. An ATB, Hi-ATB, or ATB/R combo grind will have lower tearout for crosscuts than an FTG. You might want to check that Forrest #1 to be sure it gives truly flat bottoms vs "flatter"...the term "perfectly flat" gets used inaccurately quite often.

http://i6.photobucket.com/albums/y203/hewood/sawparts/Saw%20Blades/ATB-R_profile.jpg
http://i6.photobucket.com/albums/y203/hewood/sawparts/Saw%20Blades/bladeteeth.jpg

[Howard Acheson]

Generally, a flat tooth blade will produce a slightly degraded cross cut particularly when cutting veneered plywood.

What is it you are trying to cut that you need a flat tooth blade?

Personally, I would have a General Purpose 40 tooth ATB blade for everyday cross cutting and plywood and ripping up to 1" solid wood. Then a 24 tooth FTG rip blade for ripping and when I needed a flat bottom cut. 24 tooth rip blades are quite inexpensive.

[Jeff Fuchs]

I wanted a flat grind saw blade for joinery and mitered spline boxes. I had a local carbide sharpening company grind an Freud Industrial combi blade so that all teeth are flat. It works great and leaves a flat bottom on tenons, rabits, miter splines, etc. The charged me $15 to re-grind the blade. I should be able to get three or four sharpenings out of it.

[Charles Lent]

Matthew,

You haven't said why you want a flat bottomed cut. If it's for 1/4 or 3/8" box joints, Freud makes a pair of blades that are designed to produce perfectly flat bottomed cuts (Freud SBOX8). They have special offset carbide teeth and you use the pair of blades at the same time, face to face cuts one joint width and back to back cuts the other (not sure which - it's out in the shop and not here for me to look at). This blade set does a better job of cutting flat bottoms than any other table saw blade that I've seen or used. Some dado blades are pretty good, but not as good as this set.

Charley

[Matthew Curtis]

just wondering why not get flat bottoms if you could. seem that it would make my tenons betton when cutting on a table saw, as well as rabbit cuts. Do dado sets give a flat bottom cut?

[Ronald Blue]

If you get a Ridge Carbide Tool ripping blade it will give a flat bottom. Every 3rd tooth is flat. It is also an American company and a very good value as well.
http://ridgecarbidetool.com/specials/10-ts2000.html

[scott spencer]

If you get a Ridge Carbide Tool ripping blade it will give a flat bottom. Every 3rd tooth is flat. It is also an American company and a very good value as well.
http://ridgecarbidetool.com/specials/10-ts2000.html

Ridge Carbide's RS1000 is their FTG ripper with all flat teeth. The RS2000 is an ATB/R which leaves slight bat ears at the edges of the kerf because in order to be effective, the ATB teeth must protrude slightly above the rakers.

http://i6.photobucket.com/albums/y203/hewood/sawparts/Saw%20Blades/ATB-R_profile.jpg]

[Jeff Bratt]

There's an Infinity blade designed for making flat-bottomed crosscuts for joinery...
http://www.infinitytools.com/Flat-Bottom-Crosscut-Saw-Blades/products/1484/