Large auger bits

[Ben Pierce]

Do you folks have any suggestions for sources of affordable, large auger bits? I'm talking 1 5/8" and up to maybe 3". This is for drilling large holes into end grain, specifically drilling out the recesses for plastic inserts in wooden vases. I don't believe that anything but an auger bit will work, due to the large amount of dust/shavings that needs to be evacuated from the hole.

[Tom Giacomo]

I have been using a 2 1/2" foresner bit to drill end grain out of end grain oriented vases on the lathe. Slow steady speed does quite well.

[Bruce Pratt]

Forstner bits. For large holes, I will drill in stages, increasing the diameter by about 3/4"-1" on each pass, depending on the hardness of the wood. For 1 5/8" you should be able to do it in 1 or 2 passes.

Auger bits are not really designed for lathe work. The feed screw will strip out of the wood, because of the mismatch between lathe rpm and the (manual, = irregular/slow) rate of advance of the quill in the tail stock.

[David C. Roseman]

Forstner bits. For large holes, I will drill in stages, increasing the diameter by about 3/4"-1" on each pass, depending on the hardness of the wood. For 1 5/8" you should be able to do it in 1 or 2 passes.

Auger bits are not really designed for lathe work. The feed screw will strip out of the wood, because of the mismatch between lathe rpm and the (manual, = irregular/slow) rate of advance of the quill in the tail stock.

Agree with Bruce that auger bits are not designed for lathe work, but they still work fine when used carefully. Ben's point about clearing chips is valid, and a 3" Forstner bit will be truly glacial because of it. If Ben is advancing the auger bit with the tailstock quill, it doesn't matter a lick that the feed screw strips out. In fact, it's the twist of the auger's cutting edges that wants to pull the bit into the work, so the spindle rpm as well as the feed rate must be slow, with the left hand adding back pressure to the bit shank and drill chuck to keep the Morse taper in place in the tailstock. I use a 1" auger bit to bore out peppermills on the lathe with no difficulty. With a 3" auger, the role of the bit's lead screw will be even less of a factor.

[Robert Willing]

MLCS http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/forsbit.htm sells forstner bits 1/4" to 4". I would use a drill press running no more than 250 rpms for 2 1/2" and larger.

[Ben Pierce]

Yes, I've tried Forstner bits and they cut fine but jam up in the hole very quickly, heating up the wood tremendously and requiring constant backing out and scraping the hole with a screwdriver. There's an excellent video of an Australian gent (Brendan Stemp) drilling the center hole through a recorder:
https://www.youtube.com/watch?v=NCrETz4RTyM
He explains the use of the auger bits but I haven't been able to find any in large diameters.
Thanks, folks.

[Reed Gray]

I don't drill often. When I do, I have the forstner bits. Two main things with them is they have to be sharp, and keep the speed down. I have experimented with brad tips, twist tips, but never an auger bit. I remember them from construction days and how they would self feed. If you weren't ready, they would twist the drill out of your hand (Milwaukee Hole Hog). Maybe I need to look at them again. Probably like all other tools, there are dozens of different kinds. Most interesting bit I saw was a guy who did bag pipes. Round stock, ground half round on the end, and a straight line across at 30 to 45 degrees. He drilled 10 plus inches straight in and no drifting. I have never seen them since, and never in any catalog.

robo hippy

[Paul Williams]

For deep large holes I start with the forstner bit of the size I want the final hole. I drill in about a half inch. This establishes the edge and also provides guidance for the second use of the forstner bit. Then I drill to final depth with a 1 inch, 12 inch long auger bit. I got it at Menards and ground the threaded tip to a point to reduce the self feeding. Then I return to the forstner bit to finish the hole. If it is really large or tough wood I use a size larger than 1 inch but smaller than the final hole. On a 2 inch hole I can go considerably deeper than 12 inches as the chuck fits into the hole.