Pocket knife

Stockman's penknife with (from left to right) clip, sheep's foot and pen blades; wooden grips; brass bolsters and liners

A pocketknife is a folding knife with a blade that fits inside the handle and that is small enough to fit in a pocket. Blades are typically no larger than 3 to 5 in. (8 to 13 cm) in length. Pocketknives are very versatile tools, and may be used for anything from opening an envelope, to cutting twine, to slicing an apple or even for self-defense in emergency situations.

This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (May 2009)

History

Roman period pocket knife from Gellep, Germany and reconstruction

The earliest known pocketknives date to at least the early iron age. A pocketknife with bone handle was found at Hallstatt, dating to around 600-500BC. They remain however quite rare until modern times compared to knives with fixed blades. For most of history, knives were worn inside sheaths or scabbards attached to the belt. Pockets in clothing is a relatively modern invention. Before this, pockets or pouches were attached to belts, in which these early folding knives would have been carried. In more modern times, it is often illegal to carry fixed-blade knives, which has made pocket knives much more common.

Slipjoint knives

Most pocketknives for light duty are slipjoints. This means that the blade does not lock, but, once opened, is held in place by a spring device that allows the blade to fold if a certain amount of pressure is applied. Most slipjoint locking knives have only one blade that is as large as can be fit in the handle, because the locking mechanism relies on the spring along the back of the blade to lock it and it is difficult to have multiple levers for each blade.

Some popular styles of blade shapes are:

• Clip — the upper part of the blade is cut away convexly to form a sharp point directly in front of the handle.
• Spear — edge and back curve together to a point. Probably the most common style of general purpose blade found on pocketknives.
• Peanut -- a very small slipjoint knife, designed to be legal in almost any environment.
• Drop point — similar to spear but not necessarily symmetrical
• Pen — similar to a spear but smaller. Originally intended to sharpen quill pens, but continues to be used because of its suitability to fine or delicate work. A pen knife generally has one or two pen blades, and does not interfere with the appearance of dress clothes when carried in the pocket.
• Sheep's foot (so named because of its appearance) — wide with straight edge and no point, common on boats and ships. Intended for heavier tasks such as carving wood
• Wharncliffe — flat cutting edge with back curve, similar to sheep's foot but with longer curve
• Spay or spey — clipped at the back to form a sort of point, but the clip is very short. These were originally for castrating livestock and are used for delicate work.
• Hook - The inside of the hook is sharp and the outside edge dull, so that a rope or animal skin can be cut without cutting the surface that the knife travels along. These blades are used by hunters for gutting animals and by emergency rescue people for cutting seat belts without harming the wearer.
• A whittler is slightly larger than a pen knife and has three blades.
• A stockman has a clip, a sheep's foot and a spay blade. They are usually middle-sized.
• A trapper is large, with a clip and a spay blade.
• Another traditional styles is the Sodbuster.
• An electrician's knife typically has a locking screwdriver blade but a non-locking knife blade.
• The barlow knife has a characteristically long bolster, an elongated oval handle, and two blades.^[1] It is assumed to be named after its inventor, although there is some dispute as to which Barlow this actually was.^[2][3]

Multitool slipjoint knives

Multitools have enjoyed a revival in recent years, thanks in part to newer options. These new varieties often have for the "main blade" a pair of pliers, but there is typically one or more knife blades included (e.g. spear and serrated), often locking.

A Swiss Army knife

Multitool knives often have more than one blade, including an assortment of knife blade types (serrated, plain edged, saws) as well as a myriad of other tools such as bottle openers, corkscrews, and scissors. A large tool selection is the signature of the Swiss Army Knife. These knives are produced by Victorinox and Wenger and issued to the army and sold to the public. The German Army knife is large but light, with two blades opening from each side. It has hard plastic grips and aluminum liners. The United States Army knife, made by the Camillus Cutlery Company and Imperial Schrade, used to have carbon steel blades and brass liners (both vulnerable to corrosion), but as of the Vietnam War became more durable with all-stainless steel construction. It has four blades opening from the same side. The Imperial model has a bottle opener with Standard screwdriver blade on the tip, a can opener with sharpened curved blade for piercing metal tins (and is so labeled to avoid confusion with the bottle opener), a sharpened knife blade, and an auger. The unpainted stainless steel handle has "US" stamped in the center with metal hoop for attaching to a lanyard. The handle, as manufactured, has rough edges but these can be rounded, yielding an excellent and versatile knife. Another method of non-locking knife is the friction-folder. These use simple friction between the blade and scales to hold the blade in place once opened.

The credit card knife is a very thin knife that is the shape and size of a credit card. It is designed to be carried in the wallet along with regular credit cards. Some of this shape of knife also contain other small tools, such as tweezers, or toothpicks.

Locking knives

This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2007)

Medium-sized lockback knife with deer-antler grips, nickel-silver bolsters and brass liners

A Claspknife (Opinel No. 10)

Locking knives, such as the claspknife, lock-knife, or lockback knife, have locking mechanism such as a twisting ring or catch that must be released in a distinct action before the knife can be folded. This lock improves safety by preventing accidental blade closure while cutting. In contrast, slipjoint knives have only a sliding spring keeping the blade open, and if enough force is applied to the back of the knife, the blade will close. These knives are exceedingly common in some areas of the world.

Locking knives may have appeared as early as the 15th century, in Spain. The Spanish navaja is a traditional folding knife with a long history. In the late 1800s locking pocket knives were popularized and marketed on a wider scale. Companies such as Opinel, Buck Knives, Camillus, Case, and Gerber, created a wide range of products with locks of all types. The most popular form, the lockback knife (or buck knife) is a refinement of the slipjoint, where the spring along the back of the knife has a hook on it and the blade has a notch. When the blade is fully open the hook and notch align, locking the blade in place. Closing the blade requires the user releasing the blade to apply pressure to the back of the blade and in addition press on a lever located on the back of the knife handle to disengage the hook from the notch and thus release the blade. There are other types of locks; some of the more popular ones are the Walker Linerlock, the frame lock, where the bolster inside the knife is spring loaded to engage the blade when open and thus hold it in place, and the Axis lock (a Benchmade patent). The Swiss Army knife product range has adopted dual liner locks on their 111 mm models. Leatherman and SOG tools are now available with locking blades. Opinel knives use a ring lock, where a ferrule rotates to lock the blade open.

Other features

Traditional knives were opened using nail-nicks, or slots where the user's fingernail would enter to pull the blade out of the handle. This became somewhat cumbersome and required use of two hands, so there were innovations to remedy that. The thumb-stud, a small stud on the blade that allows for one-handed opening, led the way for yet more innovations, such as the opening hole (a Spyderco patent where the user presses the pad of his thumb against a hole and opens the blade by rotating his thumb similarly to using the thumb-stud), "assisted opening" systems pioneered by Ken Onion and his "Speed-Safe" mechanism, as well as Ernest Emerson's Wave system, where a hook catches the user's pocket upon removal and the blade is opened during a draw. One of the first one handed devices was the automatic spring release, also known as a switchblade. An innovation to pocket knives made possible by the thumb-stud is the replaceable blade insert developed in 1999 by Steven Overholt (U.S. Patent no. 6,574,868), originally marketed by TigerSharp Technologies and as of 2007 by Clauss.

Another innovation of Sal Glesser, Spyderco founder, was the clip system, which he named a "Clip-it". Clips are usually metal or plastic and similar to the clips found on pens except thicker. Clips allow the knife to be easily accessible, while keeping it lint-free and unscathed by pocket items such as coins.

Legal issues

Nearly all pocketknives are legal to own in most countries, but they increasingly face legal restrictions on their use. While pocketknives are almost always used as tools, they do have the potential to become weapons. In many places it is illegal to conceal knives larger than a certain size, or with certain locking or opening mechanisms. They are often banned or heavily restricted in secure areas, such as schools and airports. Switchblades and other "auto-openers" are banned from interstate shipment by the U.S. Government and prohibited entirely in some states, though all statutes prohibiting switchblades allow an exception permitting ownership by the one-handed, the military and the police.

It is illegal to have most types of knife with you in public in the United Kingdom without 'good reason'. 'Good reason' is not defined, but examples of 'religious duty', 'national dress' and 'requirement of employment' are given. It is up to a police officer, and ultimately a magistrate to decide whether or not you meet the requirements of 'good reason' should you be found to be in possession of a knife in public^[4]. Folding knives with blades of 3 inches or less may be carried without needing to provide 'good reason' so long as the blade is not capable of being locked in the open position. However, it is illegal to have the intention of using any object in your possession whist in public as a weapon, meaning that even a knife that is legal to carry without needing 'good reason' may still be found to be illegal if the police officer has grounds to suspect it will be used as a weapon.

See also

• Navaja
• Pen knife
• Penny knife
• Knife

References

Wikimedia Commons has media related to: Pocket knives