Assertion: drill bit's purpose | /r/HasProperty | to conceal the fastener head
Facets:
value: usually
type: TEMPORAL
value: by covering the hole
type: MANNER
Source sentences:
text: The purpose of a counterbore is usually to conceal the fastener head (by covering the hole) or provide a recess to prevent the fastener from protruding above the surface of the material being drilled.