around the hole in the pivot. These bearings allow the handles of the balisong to rotate. Bushing operated balisongs have a small metal bushing slightly thicker than the tang in each pivot hole with a usually bronze disc known as a washer on each side. These washers clamp down on the bushing, but not on the tang, when the pivot screw is tightened, allowing the handle to rotate around the tang. There are also washer-only operated balisongs which are usually much cheaper and lower quality than the other kinds, as they don't need bushings, but the handles will always bind to the tang when the screws are tightened enough and the washers, tang and handles all wear themselves down much faster due to the increased friction. 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 toughness, while others are made from the recycled leaf springs of vehicles. Most modern balisongs, such as the Benchmade 51, do not use Tang Pins. Instead, they use "Zen Pins", which are two small pins embedded in the top of the handles of the balisong which make contact with the bottom of the blade. A balisong with zen pins negates the problem of having the tang pins fall out (as is typical of some cheaper models). Parts Bite handle The handle that closes on the sharp edge of the blade, and will cut the user if they are holding that handle when the knife closes. This handle usually carries the latch. 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.