tap drill

tap drill

[′tap ‚dril]
(mechanical engineering)
A drill used to make a hole of a precise size for tapping.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Using a #21 drill (tap drill), drill the hole just deep enough to thread the hole but not all the way through.
Occasionally, I'll nose into the Machinists Handbook for advice on odd thread pitches and how to select tap drill sizes for them.
With Esprit's FX capabilities, the software and the user immediately know what the feature's name was in SolidWorks, the standard of the hole (ANSI Inch, ISO, etc.), the thread class, thread depth, tap drill size and depth, which fastener we use for this size hole and any other information that can be carried over from the Hole Wizard command in SolidWorks.
The program includes calculators for angles, drill depth, simple math, and a tap drill. It also includes an automatic speeds and feeds database and calculator, and a decimal equivalent chart.
He does state very clearly and correctly to next remove the oversize "spotting" drill and change to a correct size tap drill, a # 31 gauge drill for 6-48 threads typically.
Armed with the proper location for this screw, the ideal procedure would be to locate and tap drill for the screw before ever pulling the barrel.