Body armor is an item of personal protective equipment that provides protection against specific ballistic threats within its coverage area. In this standard, the term body armor refers to that which provides coverage primarily for the torso.
Personal body armor covered by this standard is classified into five types (IIA, II, IIIA, III, IV) by level of ballistic performance.
In addition, a special test class is defined to allow armor to be validated against threats that may not be covered by the five standard classes.
The classification of an armor panel that provides two or more levels of NIJ ballistic protection at different locations on the ballistic panel shall be that of the minimum ballistic protection provided at any location on the panel.
Type IIA armor that is new and unworn is tested with 9 mm Full Metal Jacketed Round Nose (FMJ RN) bullets with a specified mass of 8.0 g (124 gr) and a velocity of 373 m/s ± 9.1 m/s (1225 ft/s ± 30 ft/s) as well as with .40 S&W Full Metal Jacketed (FMJ) bullets with a specified mass of 11.7 g (180 gr) and a velocity of 352 m/s ± 9.1 m/s (1155 ft/s ± 30 ft/s).
Type IIA armor that has been conditioned shall be tested with 9 mm FMJ RN bullets with a specified mass of 8.0 g (124 gr) and a velocity of 355 m/s ± 9.1 m/s (1165 ft/s ± 30 ft/s) as well as with .40 S&W FMJ bullets with a specified mass of 11.7 g (180 gr) and a velocity of 325 m/s ± 9.1 m/s (1065 ft/s ± 30 ft/s).
Type II armor that is new and unworn shall be tested with 9 mm Full Metal Jacketed Round Nose (FMJ RN) bullets with a specified mass of 8.0 g (124 gr) and a velocity of 398 m/s ± 9.1 m/s (1305 ft/s ± 30 ft/s) and with .357 Magnum Jacketed Soft Point (JSP) bullets with a specified mass of 10.2 g (158 gr) and a velocity of 436 m/s ± 9.1 m/s (1430 ft/s ± 30 ft/s).
Type II armor that has been conditioned shall be tested with 9 mm FMJ RN bullets with a specified mass of 8.0 g (124 gr) and a velocity of 379 m/s ±9.1 m/s (1245 ft/s ± 30 ft/s) and with .357 Magnum JSP bullets with a specified mass of 10.2 g (158 gr) and a velocity of 408 m/s ±9.1 m/s (1340 ft/s ± 30 ft/s).
Type IIIA armor that is new and unworn is tested with .357 SIG Full Metal Jacket (FMJ) Flat Nose (FN) bullets with a specified mass of 8.1 g (125 gr) and a velocity of 448 m/s ± 9.1 m/s (1470 ft/s ± 30 ft/s) as well as with .44 Magnum Semi Jacketed Hollow Point (SJHP) bullets with a specified mass of 15.6 g (240 gr) and a velocity of 436 m/s ± 9.1 m/s (1430 ft/s ± 30 ft/s).
Type IIIA armor that has been conditioned is tested with .357 SIG FMJ FN bullets with a specified mass of 8.1 g (125 gr) and a velocity of 430 m/s ± 9.1 m/s (1410 ft/s ± 30 ft/s) as well as with .44 Magnum SJHP bullets with a specified mass of 15.6 g (240 gr) and a velocity of 408 m/s ± 9.1 m/s (1340 ft/s ± 30 ft/s).
Type III hard armor or plate inserts is tested in a conditioned state with 7.62 mm Full Metal Jacket (FMJ), steel jacketed bullets (U.S. Military designation M80) with a specified mass of 9.6 g (147 gr) and a velocity of 847 m/s ± 9.1 m/s (2780 ft/s ± 30 ft/s).
Type III flexible armor is tested in both the “as new” state and the conditioned state with 7.62 mm Full Metal Jacket (FMJ), steel jacketed bullets (U.S. Military designation M80) with a specified mass of 9.6 g (147 gr) and a velocity of 847 m/s ± 9.1 m/s (2780 ft/s ± 30 ft/s).
For a Type III hard armor or plate insert that will be tested as an in conjunction design, the flexible armor is tested in accordance with this standard and found compliant as a stand-alone armor at its specified threat level.
The combination of the flexible armor and hard armor/plate shall then be tested as a system and found to provide protection at the system’s specified threat level. NIJ-approved hard armors and plate inserts must be clearly labeled as providing ballistic protection only when worn in conjunction with the NIJ-approved flexible armor system with which they were tested.
Type IV hard armor or plate inserts is tested in a conditioned state with .30 caliber armor piercing (AP) bullets (U.S. Military designation M2 AP) with a specified mass of 10.8 g (166 gr) and a velocity of 878 m/s ± 9.1 m/s (2880 ft/s ± 30 ft/s).
Type IV flexible armor is tested in both the “as new” state and the conditioned state with .30 caliber AP bullets (U.S. Military designation M2 AP) with a specified mass of 10.8 g (166 gr) and a velocity of 878 m/s ± 9.1 m/s (2880 ft/s ± 30 ft/s).
For a Type IV hard armor or plate insert that will be tested as an in conjunction design, the flexible armor shall be tested in accordance with this standard and found compliant as a stand-alone armor at its specified threat level. The combination of the flexible armor and hard armor/plate shall then be tested as a system and found to provide protection at the system’s specified threat level.
NIJ-approved hard armors and plate inserts must be clearly labeled as providing ballistic protection only when worn in conjunction with the NIJ-approved flexible armor system with which they were tested.
When looking for plates, threats and the operational environment that will be encountered needs to be anticipated in order to pick the correct plates.
For OCONUS military and para-military settings, Level IV plates capable of stopping AP rounds might be critical. For the typical LE officer within CONUS, it is highly unusual to be confronted by opponents using AP ammo; it is much more likely to be hit with FMJ and hunting rounds from rifles in calibers from .223 to .30-06, as well as 12 ga. Shotguns. Thus, multi-hit capable Level III plates are a good choice. Currently there are four main options:
Currently there are four main options for Level III plates:
Steel plates offer a very thin profile, but are a bit heavier than some other options. Steel plates are durable and offer inexpensive multi-hit capability against non-AP 7.62 x 39 mm and 7.62 x 51 mm, as well as for heavier 5.56 mm loads. Though if faced with lightweight (55 gr or less) hot loaded 5.56 mm, steel plates will be penetrated. It is a highly recommended to wear soft armor underneath steel plates.
These are very lightweight multi-hit capable plates that will stop the hot loaded, lightweight 5.56 mm ammo that defeats steel, along with the 7.62 mm threats stopped by steel. Though, they are often perforated by current military issue 62 gr M855 FMJ "green-tip" ammunition. Most of these are in-conjunctions plates, requiring soft armor underneath to be effective.
These combine both steel and hard polyethelene layers and appear to offer the best protection of any current Level III plates. They are very durable and stop multiple hits of almost all non-AP ammo, including high velocity 5.56 mm threats. These are NIJ stand-alone capable, so soft armor is not required underneath. These plates are currently available from Armored Mobility Incorporated.
These plates are relatively lightweight for the protection provided, but are often more expensive, can be fragile in day-to-day use, and usually cannot withstand as many closely spaced hits as other plate types. Ceramic plates need to be x-rayed each year to ensure that hidden cracks are not present. Ceramic plates are available in both in-conjunction and stand-alone configurations. Almost all Level IV plates use ceramic elements in order to stop AP rounds.