Drill bit question

[Joel Ficke]

I need to bore a 3" deep, 1-1/8" diameter hole in the direction of the wood grain in mahogany. There appears to be many drill bits options including: spade bits, auger bits, ship auger bits, forstner bits, and probably others I'm not aware of. Which of these types would you suggest to keep the hole straight (no drill wander along the 3" depth). Any particular features to look for? A drill press will be used and bore rate is not a concern. Thanks.

[Ken Fitzgerald]

Joel,

I favor forstner bits. In turning we often drill holes that deep to make pepper mills and it's drilled with the grain.....

[John Coloccia]

I would probably use a Forstner.

[Steven Hsieh]

What would you guys use to drill a 4" hole, about 3/4" deep? It is Melamine and its for a dust collection hose.

[pat warner]

Can, have & would use the 3-wing counterbore, upper left (http://www.patwarner.com/images/drilling_tools.jpg).
Drill 5/16 or 3/8 brad point hole first, then with matching pilot, the CB will track on down. Cheap? No.

[John Coloccia]

What would you guys use to drill a 4" hole, about 3/4" deep? It is Melamine and its for a dust collection hose.

I would draw a 4"+ a little with a compass, drill a hole somewhere inside, and then finish it with my jigsaw. Then I'd stick the hose in there and seal it with caulk. If you want to make it really neat, you can buy 4" bulkhead connectors. Then you just need to get it sorta close, put down a bit of caulk, and screw down the connector.

[Jay Rasmussen]

I need to bore a 3" deep, 1-1/8" diameter hole in the direction of the wood grain in mahogany. There appears to be many drill bits options including: spade bits, auger bits, ship auger bits, forstner bits, and probably others I'm not aware of. Which of these types would you suggest to keep the hole straight (no drill wander along the 3" depth). Any particular features to look for? A drill press will be used and bore rate is not a concern. Thanks.

I like the Forstner bit as well. Used HSS ones for years until I picked up my first carbide tipped one from Rockler a couple weeks ago, I highly recommend it. Pricy but works really well.

[Bob Vavricka]

I use the COLT MaxiCut Forstner Drill Bits for drilling end grain for peppermills and like the way they work. I can drill 8-10 inches deep with next to no drift off center in most woods.

[Sam Murdoch]

What would you guys use to drill a 4" hole, about 3/4" deep? It is Melamine and its for a dust collection hose.


To answer Joel's opening question +1 for the Forstner. To Steve - unless you have a 4" holesaw I agree with John Coloccia's jigsaw technique.

[Sam Layton]

On the three inch hole, I agree with the Forstner bit.

Steven, for a 4" in Melamine, I would use a 4" hole saw. http://www.sears.com/shc/s/p_10153_12605_00998991000P?sid=IDx01192011x000001&kispla=00998991000P&srccode=cii_17588969&cpncode=35-10444579-2

Sam

[Ole Anderson]

Assuming you have a drill press, for the 4" hole I have used an adjustable circle cutter like this http://www.amazon.com/General-Tools-55-Circle-Cutter/dp/B00004T7P1 :
http://ecx.images-amazon.com/images/I/41VMXNN02SL._SL500_AA300_.jpg
Using the slowest speed possible, cut halfway through, flip the board over and finish the cut. But if you are trying to cut a hole in a finished assembly and the drill press is a no-go just jigsaw the hole as mentioned. Do not try to use a flycutter in a handheld drill. Advantage of the flycutter is that you can adjust the bit to an exact diameter to fit your need.

[Rodney Hoyle]

Fostner bit for the small hole and if the budget allows, a Lenox 4" holesaw with speed slot plus you will need a 2L or 3L arbor(under $100 for both). If you are going to drill a lot of 4" holes over time then I would invest in the Lenox otherwise use the jig saw method.

Rodney

[Dell Littlefield]

I made an oversize plexiglass plate for my trim router. By boring a hole for a small nail, I can make a hole through relatively thick material of any size from 1 to 6 inch radius with a straight bit.

[Rod Sheridan]

Hole saw..........Rod.

[Rich Engelhardt]

1 1/8" - I'd use a Forstner bit.
If you toss a roll of masking tape on top of what you're drilling, then fix the nozzle of a shop vac over it - it whisks the chips right up slicker than slick.

For the 4" hole. I'd measure the exact size of whatever it is you're going to put into it.
If whatever you want to stick through it is exactly 4", you'll need a 4 1/8" hole saw.
Been there/done that w/a dryer vent.

Forgot to add - 3/4" isn't too bad. Any decent 18V cordless drill can handle that.
This tip is also worthwhile to prevent burning:
http://woodworkingtips.com/etips/etip031010ws.html

[Keith Avery]

You can get Silver and Deming bits that large. They should wander zero. My set only goes to 1" though and would guess 1.125" good S&D bit would run over $50.

[Ole Anderson]

You can get Silver and Deming bits that large. They should wander zero. My set only goes to 1" though and would guess 1.125" good S&D bit would run over $50.

A S&D is just a stubby twist drill with a 1/2" shank. It would have to be incredibly sharp to not tear out big time. Straight hole? Yes.