"jon_banquer" wrote in message
...
On Saturday, March 22, 2014 10:12:41 PM UTC-7, DoN. Nichols wrote:

snip

"Don't bet on *any* common drill bit being that good. If you want
precision, drill a little undersized, and then use a reamer to
enlarge the hole to the desired diameter."

Bull**** and spoken like the true amateur that Nichols is. Has
Nichols ever worked in a professional machine shop?

If you don't have to ream you save time. I'm in the time business.
Time is money. If you know what your doing and you know how to
properly sharpen drill bits and test them there is no problem
holding most drilled holes to a .002 tolerance or better.


In a professional shop I could draw Chicago-Latrobe drill bits from
the stockroom and drill correspondingly accurate holes. At home where
I pay for tooling Hanson, Vermont-American and the lower end of the
MSC line have to do. I have +0.001" oversized reamers to size and
smoothly finish plain bearings.

You could buy a few sizes of ground drill rod, like 0.125, 0.250 and
0.500, and good bits and reamers to match. Tapped and clearance screw
holes don't need to be so closely sized.
jsw