collared hole

collared hole

[′käl·ərd ‚hōl]
(engineering)
A started hole drilled sufficiently deep to confine the drill bit and prevent slippage of the bit from normal position.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

collared hole

A hole of shallow depth, drilled into a material to prevent slippage of the bit when a deeper hole is drilled.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
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References in periodicals archive ?
RTPF coils consist of multiple tubes and stacks of plate fins made with collared holes for receiving tubes.