The folding knives that are not controlled on import are generally designed with a blade
that has a bias towards closing
. The blade is held shut with the tension of a spring
along the handle of the folding knife or is designed with an effective looking device that
holds the blade in the closed position even when the blade is subjected to inertia or
centrifugal force. The Australian Customs and Border Protection Service (Customs
and Border Protection) has classified many folding knives as non prohibited imports
based on an examination of the opening methods required.
Customs and Border Protection officers do not loosen pivot screws on folding knives
unless the screws have been tightened so hard that the knife blade cannot be opened
at all, even with two hands. Classifications are made on the design of the knife or the
that are also controlled on importation.