drill-hole pattern

drill-hole pattern

[′dril ‚hōl ‚pad·ərn]
(engineering)
The number, position, angle, and depth of the shot holes forming the round in the face of a tunnel or sinking pit.
References in periodicals archive ?
Tozzer found a Y arrangement in drill-hole patterns on a Navajo gourd rattle and concluded it represented the Hyades in Taurus, the Bull.