Tameshigiri was a popular practice in the 17th century Edo period for testing the quality and keenness of a Japanese blade on items such as wara (bundled rice straw) Goza (rolls of woven rush matting), bamboo of various thickness, steel rods and sheets, occasionally cadavers and even convicted criminals.
Samurai prepare to cut through a live test subject
Highly skilled swordsmen were chosen for this position, to ensure accuracy and standardization of the test cutting. The various names of the cuts employed on cadavers explains where the cuts were made. For example, O-kesa was a diagonal cut made on an upright posed cadaver or standing condemned man, usually from left shoulder to the right hip, as this was ergonomically the most natural of cuts to make. Taitai, being a slicing of the body across the chest just below the armpits, was the second most difficult test to perform. Chiwari cut through the upper chest, Surizuke was a cut through the torso, just below the rib cage. Ichi-no-do, Ni-no-do and San-no-do where cuts through levels of the torso and stomach areas.
Bodies and live subjects were staked and tied prior to testing
Bodies would sometimes be piled up for greater effect
Mounds of sand were used to prop bodies into position
Bodies were either laid flat or on their sides during testing
Severed heads were also used for testing
Kuruma-saki cut through the navel area, while Ryu-guruma, the most difficult to perform properly, was a cut through the hips. Sode-suri saw the arm severed, Hiza-guchi sliced through the knees. Tabi-gata was a cut through ankles. These cuts were usually made on a cadaver laid out, or on a convict tied and staked over a mound of sand. Standard cuts, such as Jodan-giri, Happon-me, and Makko-giri (straight downward cuts), Yoko-giri or Tsuihei (horizontal cuts) Kesa-giri (downward diagonal cuts) Kiri-age, or Gyaku-kesa (upward diagonal cuts) were all tested. In some cases, bodies were piled up, and cuts made through a number of bodies at once.
A live subject is restrained by ropes
Subject is restrained during sword testing
A condemmed man is restrained by ropes
A criminal is staked and tied for testing
Some old swords have records known as Tameshi-mei or Saidan-mei, inscribed on the nakago (tang) listing such test information as how many bodies and what parts were cut through with that particular sword. The names of the tester, and in some cases, their impressions were engraved on the tang. Such inscriptions added to the swords value.
Tameshigiri is still practiced as a martial art form, but instead of testing the sword, it has become way of testing the practitioner’s cutting abilities.