Below you find the most common terms and descriptions for the parts of a Japanese spear.
1: Saya - The scabbard covering and protecting the blade, when the spear is not in use. There has been a great variety of designs for yarizaya, especially during the Edo era, that went much further than functional necessity demanded for at that time the yari was not only a weapon but also a symbol of status and rank.
2: E or ebu - The shaft. Usually made from Japanese live oak and often elaborately decorated.
3: Tachiuchi, also tachiuke or tachibashiri - The reinforced part of the shaft holding the nakago. As the name suggests this is the part of the shaft suitable for parrying a blade or for striking.
4: Mizugaeshi - A metal collar or a cord wrapping at the lower end of the shaft just in front of the ishizuki that is supposed to protect the shaft from water damage.
5: Ishizuki - A metal cap at the butt end of the shaft to protect it from damage by contact with hard ground but which also can be used efficiently for striking and thrusting.
6: Nakago or kuki - The tang of the blade.
7: Mekugiana - The hole (often two) accepting the mekugi, the peg affixing the blade to the shaft.
8: Hosaki - The point of the spear blade.
9: Ho - The spear blade which also simply is called Mi (body). The cutting edges are called Hasaki or simply Ha.
10: Shinogi - Ridge. hirasankaku- and seisankakuyari, blades with a triangular cross section, have one ridge whereas blades with an rhombic cross section have two ridges, just as their name ryōshinogizukuri (two shinogi) implies.
11: Machi - The lower end of the cutting edge below which starts the kerakubi.
12: Kerakubi - The neck of the blade below machi. Can appear in a variety of cross sections from circular to octagonal.
13: Kuchigane - A metal collar where the blade meets the shaft that has a function similar to the habaki (which actually can be found in some spear types like the kikuchiyari) of a Japanese sword: even distribution of impact stress onto the shaft as well as securing the blade inside the saya.
14: Gyakuwa1 - The topmost metal collar on the shaft just below the kuchigane.
15: Mekugi - The peg that affixes the blade to the shaft.
16, 17, 18, 19: Dōgane or semegane1 - Additional metal collars on the shaft below the gyakuwa which can be simple rings or correspond to the design of the gyakuwa.
20: Kaburamaki or chidome2 - A cord wrapping just below the bottommost dōgane or at the lower end of the tachiuchi respectively. Chidome refers to its function of preventing blood from flowing down the shaft as kaburamaki relates to the turnip-like form of the wrapping.