Balisong (knife)

The Balisong, also known as a butterfly knife, fan knife 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. 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 illegal in many countries such as the Netherlands, Australia, the UK, Canada, New Zealand and Germany. Balisongs are useful for situations where it is inconvenient to use both hands to open a knife. For example, a worker who is using a single hand to hold on to something as protection against falling will not wish to use that hand to open a knife. In such a situation it is useful to have a knife that can be opened with either hand. They are also common in gangs as they can be concealed in clothing. The Balisong was commonly used by Filipino people, especially those in the Tagalog region, as a self-defense and pocket utility knife. A stereotype used to exist that every Batangueno carried one everywhere he or she went.[1] Hollow ground balisongs were also used as straight razors before conventional razors were available in the Philippines. Due to legislation, they are no longer as common in urban areas as they were in past decades. The name "butterfly knife" comes from its handles which open at both sides like the wings of a Butterfly to reveal the blade. There is a wide variety of full and partial tang designs. In perhaps the most common design in full tang knives, the handle is cut in the shape of the tang and handle "slabs" are then fastened to the tang by means of pins, screws, bolts, metal tubing, epoxy, etc. The tang is left exposed along the belly, butt, and spine of the handle, extending both the full length and width of the handle. It is a misconception that this particular design defines "full tang", but it provides the greatest amount of material support to the handle of the tool. Partial tang designs include stub, half, and three-quarter tangs, describing how far the tang extends into t

e handle of the tool. The most common partial tang design found in commercial knives is on folding knives, where the tang extends only as far as the pivot-point in the handle. Scalpels, utility razor blades, and a number of other knives are commonly designed with short partial tangs that are easy to fasten and unfasten from the handle so that dull or contaminated blades may be quickly exchanged for fresh ones, or so that one style of blade may be exchanged for another style while maintaining the same handle. Hollow-handled knives also incorporate a partial tang. Many inexpensive knives and swords designed for decorative purposes incorporate partial tangs and are not intended to be used for cutting applications. A full tang knife or sword generally allows for increased force leveraged through the handle against the resistance of material being cut by the blade, an advantage when used against harder materials or when the blade begins to dull. A full tang also increases the amount of stock metal in the handle of the tool which can be beneficial in altering the balance point of the tool since the blade of a knife or sword is often quite heavy compared to the handle. Adding weight to the handle of a knife or sword to offset the weight of the blade moves the rotational balance point back toward the hand where it can be more easily manipulated to great effect, making for a nimble, agile tool. In general, a forward-balanced blade excels at chopping but sacrifices agility and ease of manipulation; a centre or rear-balanced blade excels at agility but sacrifices raw chopping power. Knives and swords intended for specific purposes will usually incorporate whichever design is most suited to how the tool will be handled for that specific purpose.[citation needed] A partial tang knife or sword is generally not able to leverage as much force against the resistance of material being cut as a full tang design would allow. This limits the amount of force which a user should apply to the handle of such a weapon. Such designs may be optimal in light-weight knives or swords designed to be kept extremely sharp and used to cut less-resistant materials. Scalpels and Japanese samurai swords are perhaps the most well-known examples of such tools.