On Tue, 09 Sep 2003 17:59:25 -0300, James P Crombie
wrote:

|Marty
| Drill your 7/8 hole with a regular drill to the proper depth.

Hard to do that when the hole is only 1/10 inch deep.


| Then
|uses a reground 7/8 drill with flat bottom. It will need a relief gash
|in the center to enable it to cut properly and I would put a small
|radius on the corners of the drill to prevent chipping.
|at this url the second pic from the bopttom shows a bottom drill
|http://www.rushmachinery.com/prod01.htm
|
|Marty wrote:
| I have to drill a number of flat bottom holes, 7/8" diameter and 1/10"
| (.1") deep in some 2/10" (.2") thick aluminum. Is there a source for
| flat bottom drill bits of this size that will fit in the 1/2" drill
| chuck that's on my drill press? If there are no bits of this size with
| a turned down 1/2" shank, can an adapter be purchased to go from the
| 7/8" bit to the 1/2" chuck? Thanks for any help. Marty
|
|
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|
|James P Crombie
|
|Summerside Machinist
|Prince Edward Island Amateur Astronomer
|Canada 3D Designer
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