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AKTI Protocol for Measuring Knife Blade Length

Where a statute, regulation or ordinance refers to knife blade length, the measurement shall be the straight line extending from the tip of the blade to the forward-most aspect of the hilt or handle.

(Approved effective January 1, 2005.)


Protocol for measuring blade length


a. The purpose of this protocol is to provide a uniform standard or method for determining the blade length of any type of knife and for the purpose of applying laws, ordinances or regulations establishing a maximum blade length. This protocol is not intended to replace or modify any specification and/or standard, such as military specifications or other standards which may be imposed by contract.

b. Manufacturers, makers and other entities engaged in the commerce of knives are encouraged to utilize the standard in product descriptions and advertising.

Protocol for measuring blade length

Open Assist

c. Law enforcement at the state, local and federal levels, as well as state’s attorneys or prosecuting attorneys, are encouraged to observe this protocol. Individuals should note that while law enforcement officials are encouraged to utilize this protocol, they are not compelled to do so. AKTI disclaims any responsibility arising from or in any way deriving from the application or misapplication of this protocol.

Protocol for measuring blade length

Straight Fixed

d. It is intended that the measurement will be made by individuals possessing ordinary, readily available measuring tools, such as a common ruler. AKTI recommends that measurements should be expressed in inches and l/8″ increments. Attempts to determine measurements to a degree of accuracy greater than l/8″ are considered impractical. The measurement should be the shortest straight line extending from the tip of the blade to the forward-most aspect of the hilt or handle and should be rounded down to the nearest whole l/8″ increment. AKTI recommends that law enforcement allow a tolerance of l/8″. Individuals are cautioned that this tolerance is a recommendation which law enforcement personnel and prosecuting officials are not required to observe.

Protocol for measuring blade length


e. There is considerable variation in the design and construction of knives, knife blades and handles. Where there is reasonable confusion as to either the tip of the blade or the forward-most aspect of the hilt or handle, AKTI recommends that the measurement which will yield the shortest dimension be utilized, unless the same would result in an absurd or obviously impractical result.

f. The drawings are for illustrative purposes only and are intended to demonstrate application of the measuring protocol as to typical folding and fixed-blade knives. These drawings may not be to scale.

Download this information as a printable handout (PDF) from AKTI.

(Drawings provided by Buck Knives and are the property of AKTI.)