The tonfa, also known as tong fa or tuifa, is a traditional Okinawan weapon from which the modern side-handled police baton is derived.
Folklore says these were originally used as wooden handles that fit into the side of millstones, or as horse bridles, and were later developed into weapons when Japanese peasants were banned from using more traditional weaponry. Other sources say they have a richer history extending back into Chinese martial arts, and appearing in Indonesian and Filipino cultures. It also appears in Thailand as the Mae Sun Sawk. The slight difference is that the Mae Sun Sawk has rope tying the elbow end of it to the arm (see the explanation below).
The tonfa traditionally consists of two parts, a handle with a knob, and perpendicular to the handle, a shaft or board that lies along the hand and forearm. The shaft is usually 51–61 cm (20–24 in) long; optimally, it extends about 3 cm past the elbow when held. Often the shaft has rounded off ends which may be grooved for a better grip. There is a smaller cylindrical grip secured at a 90 degrees angle to the shaft, about 15 centimetres from one end.
There are numerous ways to defend and attack with the tonfa. Defensively, when holding the handle, the shaft protects the forearm and hand from blows, and the knob can protect from blows to the thumb. By holding both ends of the shaft, it can ward off blows. When holding the shaft, the handle can function as a hook to catch blows or weapons.
In attack, the shaft can be swung out to strike the target. By holding the handle and twirling the tonfa it can gain large amounts of momentum before striking. The knob can be used as a striking surface, either when held by the handle, or when holding the shaft, using it as a club (when striking with the flat end) or like a hammer (when striking with the handle itself, which is an effective application of force amplification). The shaft can also be maneuvered to stab at attackers. By holding the shaft and handle together, the tonfa can be used for holding or breaking techniques. Another method as used by the Thais involves striking with the elbow end of the mae sun sawk while grabbing the handle similar to striking with the elbow in Muay Thai or Krabi Krabong. As the mae sun sawk has the elbow part of the arm attached to it, the swinging out technique described above cannot be used but offsetting that, almost all of the elbow strikes of Muay Thai can be used with great power.
The tonfa is traditionally wielded in pairs, one in each hand, unlike the police nightstick which is a single-hand weapon. As the tonfa can be held in many different ways, education in the use of the tonfa often involves learning how to switch between different grips at high speed. Such techniques require great manual dexterity, as they involve flips and slides with the weapon.