Pocketknife
（重定向自Claspknife）
![A collection of pocketknives.](/Images/godic/202501/04/Pocket_knives3810.jpg")
3810.jpg")
![Roman pocketknife: original with a modern reconstruction beside it](/Images/godic/202501/04/Roman_pocket_knife_Roman_Gellep_Germany3810.jpg")
![Smaller Opinels are a type of peasant knife.](/Images/godic/202501/04/OpinelKnifeNo33810.jpg")
A pocketknife is a foldable knife with one or more blades that fit inside the handle that can still fit in a pocket. It is also known as a jackknife or jack-knife. A typical blade length is 5 to 15 centimetres (2 to 6 in). Pocket knives are versatile tools, and may be used for anything from opening an envelope, to cutting twine, slicing a piece of fruit or even as a means of self-defense.