Stiletto designed the Fairbairn–Sykes fighting knife, a double-edged dagger with a long narrow point designed to optimize the blade for thrusting, though it was also capable of slashing strokes if the cutting edges were sharpened. Other variations of the F-S knife soon emerged, including the U.S. Marine Raider Stiletto, which was based upon the Fairbairn-Sykes knife, and the U.S. V-42 stiletto, designed from the outset to emphasize thrusting over cutting. During the 1950s, large numbers of folding switchblade or automatic opening knives with locking blades were imported from Italy to the United States. Most of these switchblades were side-opening designs, though
Stiletto fallen or severely wounded heavily armored opponent. The needle-like blade could, if used with sufficient force, penetrate most mail or find its way through gaps in a knight's plate armor, and was narrow enough to pass through the eye slits of the helmeted knight. A severely wounded opponent who was not expected to survive would be given a "mercy strike" (French "coup de grâce"), hence the name "miséricorde". Later, the Gunner's Stiletto became a tool for clearing cannon-fuse touch holes; used in the manner of an automotive oil dipstick, they were often inscribed with marks indicating levels of powder charges