19 CFR § 12.95 - Definitions.
(a) Switchblade knife. “Switchblade knife” means any imported knife, or components thereof, or any class of imported knife, including “switchblade”, “Balisong”, “butterfly”, “gravity” or “ballistic” knives, which has one or more of the following characteristics or identities:
(1) A blade which opens automatically by hand pressure applied to a button or device in the handle of the knife, or any knife with a blade which opens automatically by operation of inertia, gravity, or both;
(2) Knives which, by insignificant preliminary preparation, as described in paragraph (b) of this section, can be altered or converted so as to open automatically by hand pressure applied to a button or device in the handle of the knife or by operation of inertia, gravity, or both;
(3) Unassembled knife kits or knife handles without blades which, when fully assembled with added blades, springs, or other parts, are knives which open automatically by hand pressure applied to a button or device in the handle of the knife or by operation of inertia, gravity, or both; or
(4) Knives with a detachable blade that is propelled by a spring-operated mechanism, and components thereof.
(b) Insignificant preliminary preparation. “Insignificant preliminary preparation” means preparation with the use of ordinarily available tools, instruments, devices, and materials by one having no special manual training or skill for the purpose of modifying blade heels, relieving binding parts, altering spring restraints, or making similar minor alterations which can be accomplished in a relatively short period of time.
(c) Utilitarian use. “Utilitarian use” includes but is not necessarily limited to use:
(1) For a customary household purpose;
(2) For usual personal convenience, including grooming;
(3) In the practice of a profession, trade, or commercial or employment activity;
(4) In the performance of a craft or hobby;
(5) In the course of such outdoor pursuits as hunting and fishing; and
(6) In scouting activities.