A folding pocketknife is a folding pocketknife, right? Sort of.
While they all serve the same relative purpose, the details from model to model can vary significantly. For anyone jumping into the everyday carry realm, it can be a bit overwhelming. That's why we've put together a cheat sheet of common parts and features.
Flipper – The flipper is an opening mechanism that is part of the blade. When the knife is closed, it protrudes out the back of the handle. When you pull back on the flipper with your finger and the pressure flicks the knife open.
Thumb stud – The thumb stud is another opening mechanism. However, it's not part of the blade, it is a metal stud attached to one or both sides of the blade. Instead of pulling back on the flipper, you push out on the thumb stud.
*Note: Typically, a flipper or thumb stud both enable ambidextrous, single-handed open of a pocketknife.
SpeedSafe® assisted opening – Kershaw's SpeedSafe assisted opening was the first assisted opening mechanism brought to the market. It utilizes a torsion bar to spring the blade open when pressure is applied to the flipper or thumb stud.
Torsion bar – Most incorrectly referred to as a spring, the torsion bar is the internal mechanism in SpeedSafe assisted opening knives. The torsion bar is the heart of SpeedSafe. It helps keep the knife closed by creating a bias toward the closed position. By applying manual pressure to the thumb stud or flipper, you can overcome the resistance of the torsion bar, which creates that fast-open action.
KVT ball-bearing opening – KVT is a caged ball-bearing system that sits against the blade's pivot on the inside of the handle. KVT makes manual opening as easy as assisted—without the need for a torsion bar or other mechanism.
Detent – The detent is what keeps the blade closed in manual (non-SpeedSafe) flipper and thumb stud knives. It's a small hole in the blade that allows a ball to drop in when the blade is in the closed position. The resistance it creates when pressure is applied to a thumb stud or a flipper also helps create the quick opening.
Learn more about how opening mechanisms work including, SpeedSafe, the KVT ball-bearing system, torsion bars, and more here.
Liner lock – A liner lock is a stainless steel insert that lines the inside of the handle. When the blade opens, it springs into the locked position behind the blade. To disengage the liner lock and close the knife you press the liner against the handle allowing the blade to slide past.
Frame lock – A frame lock functions similar to a liner lock, however, instead of a stainless steel liner, a portion of the handle moves into position behind the blade when it opens.
Sub-Frame Lock – Kershaw's patented Sub-Frame Lock functions similar to a liner or frame lock. However, the Sub-Frame Lock is a lightweight variant of the frame lock and is often used on knives with lighter handles such as carbon fiber or G10. With the Sub-Frame Lock, a piece of the lightweight frame is machined out and steel is put in its place for a secure lockup.
Learn more about the locking mechanisms found on Kershaw knives here.
Miscellaneous Terms and Components
Handle scale – The handle scale is one of the largest components to comprise the handle of a knife. Two handle scales combined (with other components) make a knife handle. It can be made of aluminum, titanium, stainless steel, G10, carbon fiber, wood, brass, and other materials. Each material gives the knife a different look, feel, and weight.
Backspacer, standoff, or tube spacer – These are what help connect the two handle scales to form a knife handle. They are in the top spine of the handle and will have two or more screws running through them from one handle scale to the other. They're often incorporated into the overall design of the knife to help improve the look and feel.
Jimping – Jimping are lines or grooves down the spine of the blade or on the handle to improve grip.
Pivot – The pivot is the lifeblood of a folding knife. It's the bolt that connects the handle and the blade. When opened and closed the blade pivots on this bolt.
Hotspots – A hotspot is when your hand uncomfortably rubs on a specific location of the handle.
These are not all the knife terms and components, but they're a great start. For even more information on knife technology visit our technology page here.