Best Router Bit for cutting dados?

[Stephen Edwards]

Is there a solid carbide spiral router bit, down cut, that will cut a flat bottom dado in plywood, or any other material for that matter? If so, is this a good choice? If not, what IS the best bit for cutting flat bottom dados with minimal or no tear out?

Also, is there a significant difference in the numbers that are used to grade carbide, like 4 and 5, etc.? What does that mean?

Finally, I've seen ads for the 4 flute (cutter) Freud carbide profile bits? For folks who use the, are they worth the additional expense? Do they perform as advertised?

Thanks for your advice.

[David Keller NC]

I can't answer all of your questions (don't have a quadracut yet - the "bi-cut" bits work well enough for me not to want to replace them), but I can answer the question about a dado bit. In my experience at least, the down-cut spiral solid carbide bits from Fraud will indeed do what you want. It's what I use in my shop, though I've little doubt that CMT, Amana, Whiteside, or others would be just as good.

The downside to these bits are that they won't cut all that deep without dust extraction - the sawdust tends to build up and start burning. If you've integral dust extraction in your router, that might not be an issue.

[David DeCristoforo]

"...solid carbide bits from Fraud..."

Was that a "Freudian slip"?

[glenn bradley]

Quality solid carbide works best for me. I use a 3/8" bit and this jig (http://www.sawmillcreek.org/showthread.php?t=46406&highlight=Auto+dado)for most applications.

[Bruce Wrenn]

I use a reverse helix screw on cutter from Her-Saf. You buy an arbor, and the cutter of your choice. I have done THOUSANDS of feet of dados over the years when building cubbies for the local YMCA's. Still on my first cutter. These were originally designed to be used in CNC routers.

[Stephen Edwards]

Thanks for the replies and the info. Much appreciated.

[Fred Hargis]

is there a solid carbide spiral router bit, down cut, that will cut a flat bottom dado in plywood, or any other material for that matter? If so, is this a good choice? If not, what is the best bit for cutting flat bottom dados with minimal or no tear out?
i've had good luck with most straight bits, though i prefer the spirals. Somethign to consider is the"dado clean out bits" from mlcs (and others). I use these to clean up the "devil's ears" sometimes. http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_dado.html

also, is there a significant difference in the numbers that are used to grade carbide, like 4 and 5, etc.? What does that mean?
it's my understanding there is a geat deal of difference in carbide grading, and these numbers fit no standard. Even if they do i've seen very little difference in bit life (sharpness) across the brands...but that's just my opinion.


finally, i've seen ads for the 4 flute (cutter) freud carbide profile bits? For folks who use the, are they worth the additional expense? Do they perform as advertised?
they are (again, imho). I only have one, and wish all my profile bits had the quadra cut feature.

thanks for your advice.
hth...........

[Peter Quinn]

I use standard two flute plunge bits for cutting dados mostly. I have a set from CMT, a couple of Amana's and a few Freud's. Not much problem with chip out. I have an undersized plywood set, and have also used a jig taken from Glen Bradley's posts with a 1/2" bit and a bushing guide that works quite well. I have never found much need for spiral carbide for dados. I do use them for deeper cuts, spiral up cuts for mortises.

I have used a few Quadra cut bits, they work great, probably the only Freud profile bits I will buy hence forth. Not that the regular two flute bits are poor, but the quadra cuts are better.

[David Keller NC]

"...solid carbide bits from Fraud..."

Was that a "Freudian slip"?

Yeah - intentional. I like Fraud's tools, but I can't resist poking a little fun at the word-play that can be made from their brand name.:D

[Stephen Edwards]

Thanks again folks for your input. I decided to buy several of the Whiteside bits from Holbren.com. I ordered them last night and they shipped this morning. Spoke on the phone this morning with Brian Gumpper at Holbren. Great seeming guy. I wanted to add another bit to my order.

Thanks to the fellow creeker who told me about this company!

If you order from them be sure to enter the coupon code SMC10 when prompted to do so. You'll get a 10% discount. Finally, They are very reasonable on shipping charges.