Replies

1. 
   bilyo | Jun 06, 2022 12:41pm | #1

   I'm not absolutely sure, but what makes a combination blade, in part, is a mix of beveled and flat (raker) teeth. If you have a blade with all flat teeth, this is usually defined as a rip blade. If you need a flat bottom cut, I think, it is best to just switch to a rip blade and then switch back when your done.

2. 
   user-7627473 | Jun 06, 2022 04:07pm | #2

   I use a stock Forrest blade made specifically for splines - 1/8" kerf, flat bottom. I got mine from a Woodcraft store.

1. 
   jpe52 | Jun 06, 2022 11:12pm | #4

   On that Forrest blade, does the actual kerf come out at 1/8, or is it slightly
   oversize? I have a similar blade from Ridge, but the actual kerf is closer
   to 0.142, in spite of the teeth being accurately 0.125. Might you have the
   Forrest part number?

1. 
   jim_hall | Jun 07, 2022 12:42am | #5

   They make 3 different sizes. Here's a list of them on Slivermills website. Look for "#1" (grind) under TS column.

   https://www.sliversmill.com/category_41_Blades_for_Finger_Joints_Square_Cut_Box_Joints_Rabbets_Groo.html

1. 
   user-7627473 | Jun 07, 2022 01:59pm | #10

   Image of Forrest blade mentioned earlier

   
2. 
   user-7627473 | Jun 07, 2022 08:47am | #7

   Will check later this a.m. and let you know

3. 
   ysu65 | Jun 06, 2022 05:53pm | #3

   How about a standard rip blade?

4. 
   ral3wood | Jun 07, 2022 02:10am | #6

   If you have an older ATB blade in need of sharpening, you can just get it reground to a flat grind. Cheapest approach.

5. 
   DRBWWing | Jun 07, 2022 09:15am | #8

   What are you trying to do?

   I use a rip blade for plowing narrow grooves.

1. 
   markbarabas | Jun 07, 2022 12:50pm | #9

   General/combination blade is my preference for general woodworking, but I often like to nibble away small dados without having to change blades.

1. 
   DRBWWing | Jun 08, 2022 09:17am | #12

   For that task, another safer way to fit a dado is remove material from the material going into it rather than trying to widen the dado. This doesn't always work with plywood, but your dados really should fit perfectly off the saw with careful proper set up and running test pieces. There are nifty little dado set up gauges which I've never used you might look into.

   But, regardless, dados by definition are cross grain so can't really use a flat top blade, you're best choice is a high tooth count crosscut.

   If needed you can clean up the dado bottom with a router plane. If you don't have a router plane, get one ;-)

6. 
   user-1118538293 | Jun 08, 2022 08:53am | #11

   My understanding is that it entails a compromise. You basically have 3 main variables to manipulate: tooth count, rake angle, and tooth shape. No accident that across brands these factors are broadly similar among blades for a given application.
   If you take the top bevels away, you’re likely to sacrifice crosscut performance. At which point you are left with a not-versatile blade. Sure you can cut a speed tenon with it, but you will want to take it off to do many/most crosscuts (I predict).
   Having a flat-top blade for joinery is super useful, but the more work I do and the more my expectations of myself rise, the more I find myself sucking it up and changing blades to get the best results I can.