View Full Version : Thanks for help, "D" bit, etc.

08-04-2011, 11:14 AM
This is really a great forum here. I have been helped here quite a number of times.

Thanks to everyone for their time and expertise.

I don't remember the thread, but I recently read about making a "D" bit for reaming odd sized holes. This has saved my bacon, so to speak.

I was needing to make some extensions for some diamond burrs to reach deeper into some holes.

For this I had to ream a hole .091". I didn't have a drill bit, much less a reamer that size. Then I remembered the "D" bit. I had a piece of broken stainless shaft of the size I was needing to bore, and presto, it worked great!

08-04-2011, 11:11 PM
I have no idea which thread you're referring to, but the D bit reamers are a dodge not to be forgotten for economical hole sizing reamers. Personally, I've used hardened round lathe tools, drill blanks, drill rod, and hard shafts. Free hand grinding works for the prehardened stock while turning to size on a lathe, if required, followed by sawing, filing, drawfiling before hardening and honing on a diamond hone or oilstone after Q&T work well on drill rod stock, in my experience.

08-05-2011, 01:47 AM
I get pretty good mileage out of spade bits as well. Like a drill bit but with no helix and no flutes, ground on both sides to look like a flat screwdriver blade, but with cutting edges and angles ground like a regular drill bit.

My favorite one that I made is for making press-fit holes for leds. If I come through the pilot hole from the back of a panel, for instance, I can stop just short of reaming through. The leds fit up against a lip and it looks good. If I go through with the tip of the bit, a wider part on the bit cuts a recess for the flange on the led to nest into.