EFPs

An Explosively Formed Penetrator (EFP) is a type of explosive device designed to defeat armored targets by forming a dense, high-velocity metal penetrator at or near the moment of impact. In a typical EFP, a metal liner—often copper or steel—is fitted inside a steel or reinforced explosive case. When detonated, the explosive collapses the liner outward and upward into a solid slug or elongated projectile that travels at several kilometers per second toward the target. The form and standoff distance are carefully engineered so the liner remains cohesive and concentrates kinetic energy for armor penetration, rather than dispersing as a broad blast.

EFPs are distinguished from conventional shaped charges by their operating principle: instead of a jet formed by contacting explosives, the liner is driven to form a solid penetrator that preserves integrity over a short distance. This makes EFPs particularly effective against certain armored vehicles at close to moderate standoff, and they have been used to target hulls and armor plating rather than personnel alone.

History and use: EFP technology emerged during the 20th century and gained notoriety in late 20th and early 21st-century conflicts, where improvised devices employing EFP principles were used against armored vehicles. Variants differ in liner geometry and casing, but the core concept remains the formation of a penetrating slug rather than a conventional fragmentation charge.

Countermeasures and impact: Armor upgrades, such as spaced or composite armor, spall liners, reactive armor, and active protection systems, have reduced EFP effectiveness in some scenarios. Comprehensive counter-IED measures, vehicle hardening, and detection capabilities are also employed to mitigate risk in conflict environments.