An assisted-opening knife is a knife that uses an internal mechanism to open the blade from a closed position when slight pressure is applied to the thumbstud or the flipper.

When the knife is in the closed position, the blade is held in place by means of 1 or 2 torsion bars. As the user applies manual pressure to the thumbstud to open the knife, a mechanism such as a torsion spring moves along a track in the liner and rapidly rotates the blade into the open and locked position.

There is a big difference between "spring assisted" knives and switchblades. While a switchblade can be opened automatically with the push of a button, with an assisted-opening knife you have to apply pressure to the blade at the thumb stud or flipper. Once the assisted opening knives have been opened about one-quarter of the way, the mechanism does the rest.

Some other names for assisted-opening knife are: Forward Action Spring Technology, A/O Knife, Torsion Assist Knife, Assisted Knife, Spring Assist Knife, Spring Assisted Knife, Quick Release, Quick Draw, Alternative Automatic, Outburst, SpeedSafe, Blade Launcher and the Semi-Auto.

The first assisted opening knife was designed by Blackie Collins and a similar concept was developed years later by Ken Onion with Onion.Please see our great selection of assisted open knives below.

Need an assisted opening knife? We have assisted opening knives. Need a spring assisted knife? We have spring assisted knives