STANAG Protection Levels

STANAG 2920 Protection Levels

Military standards for ballistic protection & armour, solutions for military applications are tested according to relevant NATO standards, normally STANAG 2920 (STANAG = NATO Standardization Agreement).

STANAG 2920 The adoption of standards for ballistic protection levels and testing

Fragmentation Test (V50 Test)

Frag level F1 F2 F3 F4 F5 F6
Minimum Fragmentation Velocity V50* m/s 400 450 500 550 600 650
Minimum Fragmentation Velocity V50* ft/s 1310 1470 1640 1800 2000 2130


  • US Standard - Mill STD 662 E
  • UK Standard - UK/SC/5449
  • NATO Standard - STANAG 2920

STANAG 2920 (Ballistic test method for personal armour materials and combat clothing) is used to measure materials ability to stop fragments and shrapnel. The measuring technique was originally developed for body armour but now see general use in all situations where fragments are the primary concern. For instance, STANAG 2920 is used to measure Add-on-Armour systems for armoured vehicles.

Tests according to STANAG 2920 are conducted by shooting FSPs (Fragment Simulating Projectiles) onto the test specimen with different velocities while measuring the velocity of each FSP. By altering the velocities, after a number of shots an estimate of the ballistic limit can be obtained, which is the speed up to which the material defeats the fragment.

Combat troops rarely suffer injury or fatality from bullets but are at high risk from primary (direct) and secondary (environmental) fragmentation. To combat these threats Intelligent Armour Limited utilises a special range of Fragmentation F levels whose performance is measured by a V50 value.

International Ballistic Standards

The V50 test is the internationally recognised standard for assessing the fragmentation resistance of personal protection. The fragmentation test is conducted using Fragment Simulating Projectiles (FSPs) which are available in a range of weights approximately following the binomial progression. The test is conducted by firing FSPs at the armour at increasing velocities until an average velocity of penetrating and non-penetrating projectiles is obtained.

The higher the ballistic speed, measured in metres per second, the higher the rating of material, shown as V50 000m/s. The V50 (Velocity 50% or mean velocity) is the average of the velocities recorded for six fair impacts consisting of the three lowest velocities for complete penetration and the three highest velocities for partial penetration, provided the spread is not greater than 40 metres/second (STANAG 2920).