Butterfly knife

For the Chinese weapon, see Butterfly sword, a Chinese short-sword with a broad blade associated with the martial arts Hung Ga and Wing Chun.

A butterfly knife in open and closed position.

Animation of a butterfly knife being opened and closed.

A butterfly knife, also known as a fan knife and in the Philippines as the balisong, is a folding pocket knife with two handles counter-rotating around the tang such that, when closed, the blade is concealed within grooves in the handles. It is sometimes called a Batangas knife, after the Tagalog province of Batangas in the Philippines, where it is traditionally made. Blunt versions of these knives, called "trainers" are for sale to practice tricks without the risk of injury .

The balisong was commonly used by Filipino people, especially those in the Tagalog region, as a self-defense and pocket utility knife. A common stereotype is that a Batangueño carries one everywhere he or she goes. Hollow-ground balisongs were also used as straight razors before conventional razors were available in the Philippines. In the hands of a trained user, the knife blade can be brought to bear quickly using one hand. Manipulations, called "flipping" or "fanning", are performed for art or amusement.

The knife is now illegal or restricted in many countries, often under the same laws and for the same reasons that switchblades are restricted, and in their country of origin they are no longer as common in urban areas as they were.

Etymology

While the meaning of the term balisong is not entirely clear, a popular belief is that it is derived from the Tagalog words baling sungay (literally, "broken/folding horn") as they were originally made from carved carabao and stag horn.

Balisong is also the name of a barangay in the town of Taal, Batangas province, which became famous for crafting these knives.

The traditional balisong is said to be called the veinte y nueve because they are 29 centimeters long when opened, while another story goes that it is named after a lone Batangueño who fought off 29 assailants using one.

File:Filipinobalisong.jpg

A traditional 29 cm balisong knife, made in Batangas, Philippines.

These knives are also referred to as "fan knives" and "butterfly knives" from the motion and "click clacks" from the sound they make when they are opened and closed.

Construction

There are two main types of balisong construction: "sandwich construction" and "channel construction".

Sandwich constructed balisong knives are assembled in layers that are generally pinned or screwed together though may sometimes use a ball-bearing system. They allow the pivot pins to be adjusted tighter without binding. When the knife is closed, the blade rests between the layers.

For a channel constructed balisong, the main part of each handle is formed from one piece of material. In this handle, a groove is created (either by folding, milling, or being integrally cast) in which the blade rests when the knife is closed. This style is regarded as being stronger than sandwich construction.

Some of the blades of traditional butterfly knives in the Philippines were made from steel taken from railroad tracks thus giving them a decent amount of durability and hardness, while others are made from the recycled leaf springs of vehicles.

Parts

A diagram of common butterfly knife parts.

Bite handle

The handle that closes on the sharp edge of the blade.

Choil 

The unsharpened portion of the blade just above the kicker, that makes it easier to sharpen the blade.

Kicker (or Kick) 

Area on the blade that prevents the sharp edge from touching the inside of the handle and suffering damage. This is sometimes supplanted by an additional tang pin above the pivots.

Latch 

The standard locking system, which holds the knife closed. Magnets are occasionally used instead.

Latch, Batangas 

A latch that is attached to the bite handle.

Latch, Manila 

A latch that is attached to the safe handle.

Latch, Spring 

A latch that utilizes a spring to propel the latch open when the handles are squeezed.

Latch gate 

A block inside the channel of the handles stopping the latch from impacting the blade.

Pivot joint

A pin about which the Tang/Blade/Handle assemblies pivot.

Safe handle 

The handle (generally the handle without the latch) that closes on the non-sharpened edge of the blade.

Swedge 

Unsharpened spine of the blade. Some balisongs are also sharpened here or on both sides with either a more traditional look or wavy edges similar to a Kris sword.

Tang 

The base of the blade where the handles are attached with pivot pins.

Tang Pin(s)

Pin meant to hold the blade away from the handle when closed to prevent dulling; and, in some cases, a second pin to keep the handles from excessively banging together while the butterfly knife is being manipulated.

Blade 

The blade is the piece of steel that runs down the center of the knife that is secured by both handles when closed, one of the sides of the knife is sharp and has a high chance of cutting you, the other side has no potential chance of cutting you.

Manufacturing History

File:Ten balisong knives.jpg

A variety of butterfly knives from Pacific Cutlery, later known as Benchmade.

Balisong USA started manufacturing balisongs in the late 1970s, then change its name to Pacific Cutlery in the early 1980s, before finally becoming Benchmade. The earlier knives featured a wide variety of custom blade designs (many of which were hand ground by master knifemaker Jody Samson, well known for making the swords in the movie Conan the Barbarian), as well as a number of exotic inlays for the handles (ivory, prehistoric ivory, scrimshawed ivory, mother-of-pearl, ebony, tropical woods, etc.).

From 1981 to 1984, hundreds of thousands of balisongs were imported into the United States from a variety of countries, primarily: the Philippines, Japan, China, and Korea - although a few were also imported from France, Germany, and Spain. The best were primarily from the metalsmiths of Seki City, Japan, who manufactured balisongs for Taylor (Manila Folder), Parker (Gypsy), Valor (Golden Dragon), and Frost (a variety of very inexpensive balisongs). Guttmann Cutlery in the Philippines exported a high-quality sandwich-style balisongs marketed as the "Original Balisong", which featured a variety of scale materials and high carbon steel blades.

Legal status

Further information: Switchblade: Legality

Because of its potential use as a weapon, and mostly because of its intimidating nature and rapid deployment compared to other 50+ year old folding knife designs, the balisong has been outlawed in several countries.

• In the Philippines, it is now generally illegal to carry one without identification or a proper permit in the streets of the capital because of their prevalent use in crimes and altercations. One now needs to demonstrate the need in professional livelihood or utilitarian purpose (such as cutting grass, preparing fruits and meats, being a vendor of knives, being martial arts instructors, etc.) to be able walk around with bladed implements in the urban areas. Another rule of thumb is that the blade of pocket knives must not exceed the length of the palm and must not be openable by one hand in order to be considered as a utility knife as opposed to a weapon (thus, Swiss Army Knives are legal).
• In Australia, balisongs are generally classified as a prohibited weapon, which requires a special legitimate excuse to possess it. Australian Legal Definition: A flick knife (or other similar device) that has a blade which opens automatically by gravity or centrifugal force or by any pressure applied to a button, spring or device in or attached to the handle of the knife.
• In Canada, although not specified by name as a prohibited weapon, the balisong knife is often considered by courts to fall under the "gravity knife" or a centrifugal classification and is, therefore, prohibited, unless grandfathered in before prohibition.
• In Sweden, they are prohibited. But practice knives are legal.
• In the UK, the balisong has been legally classified as an offensive weapon since January 1989. Whilst they are legal to possess, carrying one in public is an offence under the Prevention of Crime Act 1953. Sale, lending, hiring, giving or importing is prohibited by the Criminal Justice Act 1988, as amended by the Offensive Weapons Act 1996. Any imported are liable to be seized and prosecution may follow. The exception to this are knives of this type over 100 years old which are classed as antiques.
• In Switzerland, balisongs are illegal to carry, give, lend, buy, or trade.
• In Germany, the balisong was outlawed when the Waffengesetz (weapons law) was tightened in July 2003 in the aftermath of the Erfurt massacre. Thus buying, possessing, lending, using, carrying, crafting, altering and trading it is illegal and is punishable by up to five years imprisonment, confiscation of the knife and a fine of up to €10,000. Using a butterfly knife for crime of any kind - as is any illegal weapon - is punishable by from 1 to 10 years imprisonment.
• In Finland, balisongs are legal to be purchased, sold and possessed, and are treated just like regular knives and befall under the edged weapons law. Carrying one in public is permitted if the person carrying one can prove it is used as a tool.
• In Lithuania, balisongs among other knives are legal to possess and carry as they are not considered weapons. This excludes switchblades.
• In Poland, balisongs, switchblades and gravity knives are treated like normal knives. There are no restrictions on possession and carry.
• In some U.S. states it is illegal to possess or carry such a knife in public. In certain jurisdictions, balisongs are categorized as a "gravity knife", "switchblade", or "dagger". Spyderco admitted that from June 2005 through January 2007, it had mailed balisongs, after importing the knife components from Taipei, Taiwan, through the Port of San Francisco and the Port of Oakland, to Golden, Colorado.
  • The knife is illegal to carry or sell in California, but are legal to own and collect.
  • In Hawaii, it is illegal to possess, manufacture, sell, transfer, or transport any balisong/Butterfly-type knife.
  • There were once legal restrictions on butterfly knives in Kansas., however as of July 2013, the Kansas Comprehensive Knife Rights Act decriminalized the carrying of all types of bladed weapons.
  • In Kentucky, the balisong is legal for concealed and open carrying anywhere one is not otherwise prohibited from carrying a concealed deadly weapon. Kentucky's constitution and revised statutes prohibit cities and counties from enacting weapons laws and restrictions.
  • In Michigan, the balisong is legal because it is classified as a "folding knife"
  • In New Jersey the criminal law, NJSA 2C:39-1, suggests balisongs are illegal but the question of legality or illegality is an open question.
  • In New Mexico, possession of a butterfly knife is illegal, because the butterfly knife is a "switchblade" within the meaning of the statute making possession of switchblades unlawful.
  • In North Dakota it is legal to own a balisong and carry it openly, however they are illegal to carry concealed, as they are considered to be deadly weapons.
  • In New York, the balisong has been determined not to be a gravity knife, though it is still considered to be an illegal knife. Nothing more is said in the New York State Code of Law, technically leaving individual circumstances open to interpretation.
  • In Ohio, it is legal to own a balisong and carry it openly, however they are illegal to carry concealed, as they are considered to be deadly weapons.
  • In Oregon, it is illegal to carry a concealed balisong.
  • In Texas, As of September 1, 2013 Switchblades are now legal in Texas.
  • In Utah, balisongs are legal as long as they are not concealed.
  • In Washington, the balisong is classified as a "spring blade knife," and under state law you cannot manufacture, sell, dispose of, or possess such knives.
  • In Virginia, the balisong is legal for conceal and open carrying according to state law, although localities can have additional knife laws and restrictions.
• In France, balisongs are legal.
• Balisong trainers feature a special blunt and unsharpened "blade" and are legal in some areas where balisongs are not.

See also

• Filipino Martial Arts
• Arnis
• Knife fighting
• Fighting knife
• Jacob's ladder (knife)
• Balisword
• Hackman butterfly knife
• Pantographic knife