Forstner or auger bit?

[Jonboy2003]

I have to tap a 1" x 8tpi thread in wood for lathe projects, could anyone please advise me which would be better to buy for cutting accurate 7/8" tapping size holes, a forstner or auger bit? thank you, Tony.

 

[Lazurus]

Forstner or saw tooth bit, especially if you are drilling on the lathe.

 

[MattRoberts]

I have to tap a 1" x 8tpi thread in wood for lathe projects, could anyone please advise me which would be better to buy for cutting accurate 7/8" tapping size holes, a forstner or auger bit? thank you, Tony.

Auger bits have a screw at the tip that grab the wood and help drive it through, so I wouldn't recommend using one in a drill press or lathe (assuming you were).

I'd definitely go with forstner

 

[Jonboy2003]

Thanks folks, forstner it is then, cheers.

 

[Phil Pascoe]

Auger bits have a screw at the tip that grab the wood and help drive it through, so I wouldn't recommend using one in a drill press or lathe (assuming you were).

I believe you can now buy them without the lead screw for use on a lathe or drill press.
I've often used conventional augers in my drill press - I've just clamped the work down overhanging the side. The screw ceases to grab as it exits the underside allowing you to turn the work over to finish the hole from the other side. You have no hope of boring a blind hole, though.

 

[MikeG.]

Forstner is the obvious answer, but if you have an auger and not a forstner, then drill a pilot hole, (and clamp your workpiece down over a piece of scrap for those using a pillar drill). An auger or even a spade bit may be the correct answer if precise location is more important (again, this doesn't apply in a lathe).

 

[Jonboy2003]

Thanks again for input, Tony.

 

[Robbo3]

Auger bits have a screw at the tip that grab the wood and help drive it through, so I wouldn't recommend using one in a drill press or lathe

I've read this advice on a number of occasions, however on making some pepper mills on the lathe, was wary that the auger might pull through - but it didn't.
I surmised that the grip of the screw wasn't strong enough to overcome the other forces involved. If it were, then the chuck would be pulled out of the morse taper & lose its forward motion. It might revolve but the centrifugal force would be checked by the tailstock allowing the lathe to be turned off.
A draw bar would solve both problems.

 

[Phil Pascoe]

You'd possibly get away with it on a lathe making mills, you're going into end grain - but if going into long grain (at least with some of the augers I have) I'd be asking for an injury or for something to be wrecked. I wouldn't attempt a blind hole on a drill press, although I suppose it could be worth a try if you are actually trying to pull the chuck out.