Switchblades and Automatic Knives

Switchblade Introduction

A switchblade is simply a knife which can open very quickly because the opening mechanism is powered by mechanical energy stored in a spring. Inside the handle there is a piece of spring steel which wants to bend. The end of this presses against the blade (at the lowest part, near where the handle connects with the sharp part). The thing stopping the spring from pushing the blade out is a small metal pin that fits into an indentation in the blade. Pressing the button moves this pin out of the way, and the blade opens quite quickly.

A switchblade (also known as automatic knife, switch, or in British English flick knife) is a A pocketknife having a spring-operated blade that opens instantly when a release on the handle is pressed.

Switchblades are legal weapons in the Russia and parts of the U.S.A., often covered by very specific laws—many of which appear to have been enacted at times of moral panic by newspapers and films about supposed knife use.

There are two basic types of switchblades, side-opening / folding switchblades and OTF switchblades (Out-The-Front or telescoping). A side-opening knife's blade pivots out of the side of the handle (in the same manner as an ordinary folding knife, except with the press of a button). An out-the-front knife's blade slides directly forward, out of the tip of the handle. There are two types of OTF (out the front) knives: double action and single action.

Double action OTFs allow the user to extend or retract the blade with the press of a sliding button. Spring tension in these knives is actually provided by the movement of the button, which makes them much safer to carry since they will not open accidentally. However, the extra force the spring requires can also make intentional opening more difficult.

Single action OTFs require the user to retract the blade manually and compress the spring. Because they often use a lever to compress the spring, stronger springs can be used. This makes them open more vigorously than the double-action type, and allows them to achieve tighter lock-up.