clearance hole
Technical term in mechanical engineering and manufacturing. A hole drilled large enough for a bolt or screw to pass through without engaging the threads.
This part has a clearance hole for an M6 bolt.
The diameter of the clearance hole is made slightly larger than the outer diameter of the bolt.
Standard technical spelling using katakana for バカ and kanji for 穴.
Kanji spelling for バカ; less common in technical contexts.
Compound of バカ (foolish, useless) and 穴 (hole). The name suggests a hole that does not perform the 'smart' function of holding a thread, i.e., it is a simple through hole.