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.