Sliding knife

Sliding knife
An OTF knife, showing the blade being extended from the handle.

An OTF Knife, also known as an out-the-front knife, sliding knife, or telescoping knife, is a pocketknife with a blade that opens and closes through a hole in one end of the handle. Contrast this with the majority of knives, which are either standard folding knives or are "fixed blade" sheath knives (having no mechanical operation).

"OTF" only refers to the basic portion of the knife's mechanical operation where the blade slides parallel with the handle to deploy.

OTF knives may be further subdivided into manual sliding knives, which are not restricted as inertia knives, and automatic OTF switchblade knives and gravity knives, which are restricted offensive weapons.[1]

Switchblades and gravity knives provide a great variety of different OTF mechanisms..


"Gentlemen's" OTF knives

OTF knife GM06.jpg

Illustrated above are four very small OTF knives. Figure A shows simple rocking jaw type button, and Figure B is a roll-lock design. Both figures depict gravity knives that fall open. The leading edge of the roll cap or jaw acts as a hole cover when closed, and rests in a groove milled across the open blade tang in order to lock open.

Figures C and D are known as sliders or sliding knives. The knife blade must be pushed with the button along the length of the handle, finger pressure must overcome friction. The lock buttons on C & D are not automatic releases. Figure C is a Christy Cutter (trademark) and Figure D is an antique design. The simplicity of sliding mechanisms have allowed some knife manufacturers to build extremely thin gentlemen's models, that are very comfortable to pocket.

Automatic OTF knives

An automatic OTF knife blade travels within an internal track or channel in the same manner as a manual slider or gravity knife. But the automatic main spring drive and button mechanism enclosed within requires a switchblade handle to be thicker or longer than a similar size gravity or sliding knife. The term "Slider" is usually not applied

There are two types of "Out the Front" automatic knives, DA-OTF (double-action) and SA-OTF (single-action). Double-action OTF knives deploy and retract with a multifunction button and spring design[1]. Single-action OTF knives deploy automatically, but must be manually cocked or retracted to close.

Despite popular belief and movie magic, OTF automatic knives are not powerful enough to open when pressed against an opponent and then pushing the button. Double-action sliding autos are only spring-powered 10 to 12 millimeters; afterwards, kinetic impetus slides the blade to full open. Single-action OTF autos have a spring drive the full length of blade travel, but the size of the contained main spring is never large enough to drive a blade through much resistance.[2] This is possibly a misbelief based on confusion with the ballistic knife which has a secondary handle tube with a robust coil spring for launching a fixed blade knife.

Gravity OTF knives

A gravity OTF knife is also not considered a slider, because the blade extends outward by force of gravity or inertia, instead of finger pressure. The most famous gravity knife is the Fallschirmjaeger-Messer, or German paratrooper knife of World War II. The term gravity knife should primarily reference the Fallschirmjaeger-Messer as the archetypical example.[3]

Spring-assisted gravity knives

Some civilian gravity OTF knives have a small helper spring to kick out the blade. This partial spring drive is not sufficient to classify this type of knife as a switchblade, because it does not drive the blade out to full lock.

Sheath-deployed telescoping knives

Another type of telescoping sliding knife is the Kershaw Ripcord. This is a sheath knife that partially retacts into the handle, and has a small scabbard cap covering the remaining blade tip. The design utilizes a specialized belt hanger/holsters that grasps the retracted blade so the blade is pulled fully open when unholstering. It is a unique compact fixed blade alternative. During the 1990s, a similar sheath-activated sliding knife with embossed Red Star handle was sold in the United States, claimed to be a police knife from the People's Republic of China. However, no proof of this assertion has been shown.

Roll-lock sliding knives

A roll-lock knife is a type of sliding knife in which the blade rides on a track running the length of the scales, tilting into a detent to lock open or closed. Examples would be the Bench Mark Rollox, or its licensed derivative, the CRKT Rollock. Sliding knives like the Rollox are not considered inertia or gravity knife.

Spring-assisted out-the-front knives

Schrade and Smith & Wesson have both recently introduced OTF knives that are opened by sliding forward a handle attached to the blade to engage the torsion spring. As it is classified as spring-assisted, it is not covered by the Switchblade Act of 1958 and is therefore legal everywhere in the U.S.

See also


  1. ^ Double Action Mechanism
  2. ^
  3. ^ Gravity Knife OTF & Sliders

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Knife — A knife is a handheld sharp edged instrument consisting of handle attached to a blade used for cutting. The knife is a tool that can be used as a weapon. Its origins date as far back as two and a half million years ago, as evidenced by the… …   Wikipedia

  • sliding microtome — n a microtome in which the object to be cut is fixed and the knife is carried obliquely across it * * * a microtome in which the specimen being sectioned is made to slide on a track …   Medical dictionary

  • sliding microtome — noun : a microtome in which the object to be cut is fixed and the knife is carried obliquely across it compare rotary microtome …   Useful english dictionary

  • Pocket knife — A pocket knife is a folding knife with one or more blades that fit inside the handle that can still fit in a pocket. It is also known as a jackknife or jack knife.[1][2] Blades can range from 1 cm (1/2 inch) to as much as 30 cm… …   Wikipedia

  • Utility knife — Boxcutter and box cutter redirect here. For the electronic music artist, see Boxcutter (musician). For season four premiere of Breaking Bad, see Box Cutter (Breaking Bad). A utility knife is a knife used for general or utility purposes.[1] The… …   Wikipedia

  • Combat knife — USMC KA BAR Combat Knife A combat knife is a fighting knife designed solely for military use and primarily intended for hand to hand or close combat fighting.[1] Since the end of trench warfare, most military combat knives have been secondarily… …   Wikipedia

  • Opinel knife — The Opinel knife, or simply Opinel, is a simple, wooden handled pocket knife manufactured since 1890 in the town of Saint Jean de Maurienne in the Savoie region of France. No. 10 Opinel knife with carbon steel blade, Virobloc twistlock, and… …   Wikipedia

  • Chef's knife — A chef s knife In cooking, a chef s knife, also known as a French knife or a cook s knife, is a cutting tool used in food preparation. The chef s knife was originally designed primarily to slice and disjoint large cuts of beef. Today it is the… …   Wikipedia

  • Cleaver (knife) — Main article: Kitchen knives Chinese chef s knife (top) and old North American cleaver (bottom) …   Wikipedia

  • Ontario Knife Company — Ontario Knife Company, also known as OKC , is an American manufacturer of knives and other edged tools. The OKC 3S Bayonet Ontario Knife Company was founded in 1889 in Naples, New York. The company takes its name from Ontario County, New York… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.