USML Category XIII: materials, armor and cryptography

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1. A category of many parts

Under the International Traffic in Arms Regulations (ITAR), Category XIII of the United States Munitions List (USML) is headed "Materials and Miscellaneous Articles" (22 CFR 121.1). It gathers several unrelated groups: military cryptography, advanced materials, armor, concealment and signature reduction, energy conversion devices and low observable tooling. Paragraphs (a) and (c) are reserved. Paragraph (m) collects the interpretations that explain the category’s terms, and paragraphs (n) to (w) are reserved. Paragraph (f), with an asterisk, catches any article in the category that is classified, contains classified software tied to defense articles or 600 series items or is being developed using classified information.

2. Military cryptography

Paragraph (b) covers information security and information assurance systems, cryptographic devices, software and components (22 CFR 121.1). It lists military or intelligence cryptographic systems, including key management, able to maintain the secrecy or confidentiality of information or information systems. That includes equipment or software for tracking, telemetry and control encryption and decryption. Military or intelligence cryptographic systems able to generate spreading or hopping codes for spread spectrum equipment are listed separately.

The paragraph also covers military or intelligence cryptanalytic systems, equipment and software (22 CFR 121.1). It reaches cross domain systems authorized to control access to or transfer data between security domains, as listed on the control list of the National Cross Domain Strategy and Management Office, including previous and derived versions. Ancillary equipment specially designed for those articles completes the paragraph. Every cryptographic and cryptanalytic entry in the paragraph is limited to military or intelligence systems.

3. Advanced materials

Paragraph (d)(1), with an asterisk, covers ablative materials fabricated or semi-fabricated from advanced composites, such as silica, graphite, carbon and boron filaments, specially designed for Category IV missiles or Category XV spacecraft (22 CFR 121.1). The asterisk puts these materials in the Significant Military Equipment class (22 CFR 120.10). Paragraph (d)(2) covers carbon/carbon billets and preforms reinforced in three or more dimensional planes (22 CFR 121.1). It excludes those where third-dimension reinforcement is limited to interlocking adjacent layers. Paragraph (d)(1) carries the (MT) annotation where usable for nozzles, re-entry vehicles, nose tips or nozzle flaps of rockets, space launch vehicles or missiles with a range of 300 km or more. Paragraph (d)(2) carries it for billets and preforms designed for such systems and usable at that range. The note defines range in the same words used for Category IV rockets.

4. Armor

Paragraph (e) covers armor and armor materials, whether organic, ceramic or metallic (22 CFR 121.1). Spaced, composite and metal laminate armor are caught with a mass effectiveness ratio (Em) greater than 1.4 and protection meeting NIJ RF1 or better. Transparent armor at an areal density of 40 pounds per square foot or less is caught with Em of 1.3 or more, or lower Em but meeting NIJ RF1. Transparent ceramic plate over one quarter inch thick and larger than 8 inches by 8 inches, other than glass, is covered, as are untreated ceramic plates and blanks of that size, including spinel and aluminum oxynitride.

The category defines its armor terms (22 CFR 121.1). Composite armor has more than one layer of different materials or a matrix. Spaced armor uses an air space, obliquity or a discontinuous material path as part of the defeat mechanism. Reactive armor places explosives, propellants or other materials between plates to enhance plate motion or otherwise defeat the penetrator, and electromagnetic armor uses electricity to defeat threats such as shaped charges. Metal laminate armor is two or more bonded metal layers. Composite armor materials may include metals, plastics, elastomers, fibers, glass, ceramics, encapsulated ceramics and ceramic balls in a cast metal matrix. The vehicle armor entries of Category VII rely on these same interpretations. A material is transparent if it transmits 75% or more of visible light through a 1 mm sample, corrected for index of refraction.

Em compares the tested armor’s performance with rolled homogenous armor, using areal densities and penetration measured against a witness plate (22 CFR 121.1). NIJ RF1 refers to National Institute of Justice Standard 0123.00. Developmental armor funded by the Defense Department under documents dated July 8, 2014, or later is also covered. Body armor itself sits in Category X, personal protective equipment.

5. Concealment and signature reduction

Paragraph (g), with an asterisk, covers concealment and deception equipment (22 CFR 121.1). It includes magnetic-loaded polymers within a stated surface resistivity range, and multi-layer camouflage systems specially designed to reduce detection in the infrared or ultraviolet. Radar absorbing materials specially designed for defense articles or military items subject to the Export Administration Regulations are listed too, in two forms. One is ceramic or magnetic material for operation above 300 °F. The other is broadband magnetic material with more than 30% bandwidth weighing less than 2 lbs per square foot. Paragraph (j)(2), also asterisked, covers equipment, materials and coatings specially designed to modify the signatures of defense articles or 600 series items subject to those regulations through control of absorption, reflection or emission to reduce detectability.

Paragraph (i), with an asterisk, covers signature reduction software and technical data (22 CFR 121.1). It includes software for measuring or modifying signatures, designing low-observable platforms and predicting infrared or radar cross section signatures. It also covers signature management codes and algorithms, signature control design methodology, and data on micro-encapsulation, camouflage, surface treatments and the modification of acoustic and other signatures. Paragraph (k), asterisked, covers tooling for production of low observable components and portable equipment that validates field repairs to signature reduction structures.

6. Energy devices, fluids and data

Paragraph (h) covers energy conversion devices not listed elsewhere: fuel cells, thermal engines and thermionic generators specially designed for listed platforms or soldier systems, and thermal batteries (22 CFR 121.1). Thermal batteries are single use batteries with a solid salt electrolyte, activated when a pyrolitic material melts it. Paragraph (j) also covers treated dyes, coatings and fabrics for sensor-defeating protective clothing, and fluids specially designed for named aircraft, engines and other articles. Paragraph (l) controls technical data and defense services for the category. Paragraph (x) covers related items under the Export Administration Regulations.

Key terms

Em	The mass effectiveness ratio comparing armor performance with rolled homogenous armor.
Transparent	Transmitting 75% or more of visible light through a 1 mm sample.
Reactive armor	Armor with explosives or other materials between plates to defeat a penetrator.
Radar absorbing material	Material controlled when specially designed for defense articles and meeting heat or bandwidth tests.
Cross domain system	A system authorized to control access to or move data between security domains.

Every statement above links to the document behind it. The full source list for this piece is on the sources page.

This page describes public United States government programs for general information. It is not legal, regulatory or procurement advice, and it does not address the facts of any particular case.

How Sentfore supports this

Armor and secure communications are part of every protected deployment. Sentfore works at the delivery end of defense programs in difficult environments, providing secure movement, protective security, facilities and life support. Requirements can be sent through the contact page.