Editor’s Note: This is an excerpt from a longer feature that appears in KNIVES 2020. Get the book here.
A fierce demand for flipper folders emerged in the past few years. Popular with the tactical and everyday carry crowds, new custom and production flippers reinvigorated the market. Each model sports the hallmark of a flipper tab that allows the use of one’s index finger to deploy the blade at a moment’s notice.
Flipper Folders’ History is Tied to Assisted-Opening Knives
Early flipper folders were used in conjunction with assisted-opening mechanisms as a means for initiating movement, allowing the spring or torsion assists to open the blades the rest of the way. A few years later, folder pivots incorporated ball bearings, nearly negating the need for assisted-opening mechanisms on flippers.
This reduced friction simplified folder construction and provided glassy smooth blade rotation. Although a few companies still offer assisted-opening flipper folders, most production versions rely on ball bearings.
Flipper Folders: Function Flows From Form
A flipper tab and ball bearings don’t necessarily equate a folder with quick action and secure deployment. A flipper mechanism will not work properly without a well-designed detent.
Imperative is the detent’s power to secure and hold the blade shut. When placing pressure on the flipper tab with an index finger, the user should be able to feel the grab of the detent. With more pressure on the flipper, the inertia of the blade overrides the pressure of the detent, and kinetic energy swings the blade into the fully open and locked position.
An imprecise detent results in either sloppy action or a flipper mechanism that requires too much pressure against the narrow tab. Optimally, with pressure on the flipper tab, the detent holds its load for a second before letting the blade go with enough energy to snap it open.
Finding Fun in the Fidget Factor
It’s the flipper action that is so satisfying. It imbues a “fidget factor” that causes knife users to snap open their folders while watching TV, talking on the phone, lying in bed or practicing any number of mundane daily routines.