What common size holes are drilled for timber frame?

Guys, I have developed a drill bit that will drill 36" deep in end grain in one minute flat. This drill is normally used by woodturners to drill out the center of a tall turning. However, I also have a variation that fits into a half-inch electric drill that will drill at about the same speed without the wood turning. My question is: What are the common sizes you guys normally drill? No use making a 3/4" diam drill bit if no one uses that diameter, eh?

Thanks,
James Johnson
Kerrville, TX

I don't spend a lot of time drilling into end grain... Timberlinx connectors use end grain holes, however, and the size for those is 1 1/8
does your drill work across the grain as well?
-m.

Yes, it drills crossgrain just as well as it drills endgrain. But the drill for consideration by timber framers doesn't require the wood to turn as does the drill for woodturners. Instead, you use a 1/2" drill motor to power it. Also required is an air compressor. The little pancake jobs will do. The air blows the chips out of the drill. They will drill about 15" deep. But if someone wanted one to drill deeper, I could easily build it.

Thanks,
James Johnson