bottoming drill

bottoming drill

[′bäd·əm·iŋ ‚dril]
(design engineering)
A flat-ended twist drill designed to convert a cone at the bottom of a drilled hole into a cylinder.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Next, we'll switch to a bottoming drill, still of the tap drill size, which cuts a flat bottom hole instead of the usual 135 degree cone pointed drill which would have drilled a hole closer to the rifling at the center than at the perimeter.
A bottoming drill, which was considered good practice by Mr.