1.1 This specification covers an acceptable countersink instrument intended to countersink a drilled pilot hole in bone to receive the tapered head of a medical bone screw. The specific design covered by this specification incorporates a pilot tip of suitable diameter to engage the pilot hole and a countersink contour for medical bone screws conforming to Specification F543.

1.2 The values stated in inch-pound units are to be regarded as the standard.