Bit Choice for Drilling 2-Inch Holes in White Oak
This much drilling in hard wood is a torture test for any bit. What's the best bit for the job? August 8, 2010
Question
I need to drill a 2" hole through several (116) white oak post brackets. The bracket is 5" thick. The wood has been dried to 16%. I plan on using a drill press. What would be the best bit to use?
Forum Responses
(Solid Wood Machining Forum)
From contributor D:
Any bit you use will be dull by the time you finish those. I'd just buy several spade bit and keep them sprayed with something like Bostik DriCote. If you aren't in a hurry, let the bits cool down every so often doing other things. If things start smoking, it will be a long task.
From the original questioner:
Thanks for replying. I looked for 2" flat bits and couldn't find any locally. Do you know where I could order some from? I was about to order a Bormax forstner bit. They are made in Germany and are supposed to be very sharp and long lasting. They cost about $85. I found them at Traditional Woodworker's website.
From contributor S:
What about making a template and using a router with a collar on it? You can get an upcut bit to remove the waste as you go.
From contributor P:
So if I read this right, quantity 116 with two inch diameter holes, five inches deep in white oak. That is a lot of work. Assuming your drill press has five inches of travel and sufficient power, I would go with a inserted spade drill and arbor. Not the woodworking style, but for metal working. It requires that you drill a 3/4 pilot hole first with a twist drill. Then pilot the spade drill through. It’s low on power requirements and does a slick job.
From contributor R:
I would use a Forstner. Standard steel would work well and can be easily sharpened or you can get carbide if you prefer, most of this size have a toothed rim and are fairly aggressive. You will definitely want to use a press and with a backup piece underneath you will get a clean exit.
From contributor L:
A multi-spur bit will drill those all day with no problem. I only use Forstner bits for specific applications such as flat bottomed holes, etc. Lee Valley Toothed Forstners are darn close to a multi-spur bit and priced affordable. For multi-spur bits see Fuller, Morris, Mcmaster. They are pricey but the best choice. We used them in the production shops on a daily basis.
