KE-penetrator is a type of ammunition using kinetic energy as the primary means of penetrating armour. Ammunition of this kind lacks explosive, so in order to successfully penetrate modern armour, the round must travel at a high velocity and the force of impact must be concentrated to a small area. These requirements have led to the round commmonly being shaped as a long sleek rod with fins at the end, similar to a dart. The diameter of the round is usually made significantly smaller than the caliber of the gun firing it. This enables use of large propellant charges, maximizing velocity, and concentrates the force of impact in the target. Additionally, this keeps air drag to a minimum. To keep the penetrator centered in the barrel and prevent propellant gases from leaking out during firing, a sabot is placed around the penetrator, but this falls off as soon as the round leaves the barrel.
KE-penetrators for tanks are commonly just 2-3 centimeters in diameter, and 50-60 centimeters long. To maximize the amount of kinetic energy released on the target, the penetrator must be made of an hard and heavy material, such as tungsten or depleted uranium. If the penetrator was in a soft material such as lead its kinetic energy would be dissipated as heat hitting the hard armor and no effective penetration would happen.
Other names for KE-penetrators include APFSDS (Armour Piercing Fin Stabilized Discarding Sabot) and long-rod penetrator. It is generally accepted that KE-penetrators are the most effective ammunition in penetrating armour today.