Blade size for plywood/laminate- why 10"?

[Gator95]

Will be looking for a good plywood blade to complement my Forrest 30T WWII eventually. Was thinking... since the maximum laminate/plywood thickness I might ever think of cutting would be 1" max- and add to that 3/4 inch for sled thickness- what is the point of a 10" TS blade for laminates?

Why wouldn't they all be 8 or 9"? Seems like that would run slightly smoother and be more economical. Might still wind up with a 10" blade anyways if there is another amazon blowout on the HiATB 80T freud but it just seemed interesting when I thought about it that there is no way to use that extra couple inches when cutting plywood- seems like a waste.

[Tequila]

Two reasons I can think of:
1) Sometime you might want to cut some laminated ply, which could be 1-1/2" or more thick.
2) It's cheaper to manufacture stuff in less sizes, so if Freud has a line of tooling dedicated to make 10" blades, it's probably a lot cheaper and easier to add another style of 10" blade than it is to put in another line for 8" or 9" blades. Making one 8" blade might be cheaper than making one 10" blade, but the cost structure changes when you're talking about making a few thousand of them.

[drumpriest]

probably because 10" is such a standard size, the blanks are just made that size. 8" is pretty common too though, in dado blades. Of course there is thicker plywood than 23/32". You can get 1 1/2" plywood, for instance.

[drumpriest]

Ha ha, Joe typed that as I was typing mine, same points made.

[LarryG]

I have trimmed built-up assemblies that were around 3" total thickness, with hardwood plywood on both sides, to final size on the table saw; so that might be one instance when you'd want the added depth of cut of a 10" blade. But for the most part, you're right ... for perhaps 99% of all woodworkers, an 8"-9" plywood/laminate blade would be fine perhaps 99% of the time.

I have a 7-1/4" Freud "finish" blade (can't recall the model number) that I use mainly to cut MDF. Intended for circular saws, it cuts this material essentially as well as my better blades -- and with a lot less dust, due to the ultra-thin kerf.

Your second paragraph alludes to a possible practical consideration, though. I have a 10" Forrest Duraline plywood/laminate blade. They also offer this blade in 7-1/4" and 8" sizes, but thanks to amazon.com's periodic blowout sales I was able to buy the 10" for a lot less than either of the others would have cost.

[LCHIEN]

a few good points made already about blanks and economies of scale for standard sizes.
I'd also like to point out some physical/technical advantages:
1. Given fixed RPM, 10" blade will have greater tip velocity (by 25% over 8" blade)=smoother cut
2. Can have more teeth of same geometry = more cuts per revolution = smoother cut
3. More teeth = longer life of blade
4. More mass, more outer radius weight concentration = greater inertia = smoother cut

[Knottscott]

Did you happen to spot this Amazon Forrest bargain? 9" isn't as much of a compromise as the 8" and at $50 shipped it's a heck of a deal. 60T Hi-ATB. Excellent ply and crosscutter with good versatility. An 80T of a similar design should cut a tad cleaner but will have greater resistance, more tendency to burn, as well as poor versatility....never a free lunch!