018-013   Tap-Drill Chart – U.S. Customary and Metric

Table of Contents

General Information

General Information


NOTE ON SELECTING TAP-DRILL SIZES: The tap drill sizes shown on this card give the theoretical tap drill size for approximately 60% and 75% of full thread depth. Generally, it is recommended that drill sizes be selected in the 60% range as these sizes will provide about 90% of the potential holding power. Drill sizes in the 75% range are recommended for shallow hole tapping
(less than 1 1/2 times the hole diameter) in soft metals and mild steel.

Last Modified:  03-Mar-2004