Trinitrotoluene is one of the most commonly used explosive materials by military forces. One of the big reasons for this is that it's very resistent to shocks and friction, which makes it difficult to detonate.
Because of this, TNT was originally ignored as an explosive material and actually used as a yellow dye! Eventually the Germans began using it in their artillery shells. Here, the delayed detonation actually served to its advantage. The German shells would explose inside British ships. The British ones, on the other hand, exploded on contact, wasting most of the explosive energy on the outside of the ship.