Quick answer: A katana has two main groups of parts: the blade (tōshin) and the mounting (koshirae). The key blade parts are the kissaki (point), ha (edge), hamon (temper line), shinogi (ridge line), mune (spine), and nakago (tang). The key mounting parts are the habaki (blade collar), tsuba (guard), tsuka (handle), menuki (handle ornaments), mekugi (retaining peg), and saya (scabbard).
If you have ever read a sword listing and wondered what a "fuchi" or a "koiguchi" is, this guide is for you. Below, every part of a katana is named, located, and explained in plain English, so you can read a spec sheet, talk to a polisher, or inspect a new sword with confidence.
The blade (tōshin)
The blade is the sword itself. Everything else is a fitting that can be removed and replaced.
| Part | Japanese | Where it is | What it does |
|---|---|---|---|
| Point | Kissaki (切先) | The tip section, bounded by the yokote line | Handles thrusts and tip cuts; the hardest area to polish |
| Yokote | 横手 | The line separating the kissaki from the body of the blade | Defines the point geometry |
| Bōshi | 帽子 | The hamon inside the kissaki | Shows how the temper line turns back at the tip |
| Cutting edge | Ha (刃) | The sharpened lower edge | Does the cutting; hardened during clay tempering |
| Temper line | Hamon (刃文) | The misty boundary above the edge | Marks where hard edge steel meets the softer body |
| Blade surface | Ji (地) | The flat area between hamon and shinogi | Where grain pattern (hada) is visible on folded steel |
| Ridge line | Shinogi (鎬) | The raised line running along the blade | Stiffens the blade and shapes its cross-section |
| Ridge face | Shinogi-ji (鎬地) | The surface between shinogi and spine | Often where a groove (hi) is cut |
| Spine | Mune (棟) | The thick back of the blade | Absorbs shock; never used to cut |
| Groove | Hi (樋), e.g. bō-hi | A channel along the shinogi-ji | Reduces weight and creates the "whoosh" sound in a swing |
| Curvature | Sori (反り) | The arc of the whole blade | Helps draw cuts and smooth drawing from the saya |
| Notches | Ha-machi / Mune-machi (区) | Small steps where the blade meets the tang | Seat the habaki; blade length is measured from here |
| Tang | Nakago (茎) | The unpolished part inside the handle | Anchors the blade to the handle; a full tang runs the length of the tsuka |
| Peg hole | Mekugi-ana (目釘穴) | A hole through the tang | Where the mekugi passes through to lock the handle on |
| Signature | Mei (銘) | Chiseled into the tang | The smith's name, date, or inscription |
Two of these parts deserve a closer look. The hamon is the clearest sign of real differential hardening, and it is worth learning to read. Our guide to hamon types covers the common patterns, and how a katana is clay tempered explains where it comes from. The nakago matters because a full tang is what makes a sword structurally sound; see full tang katana benefits for why.
The mounting (koshirae)
The koshirae is everything that dresses the blade: guard, handle, scabbard, and their fittings. Historically, a single blade might wear several koshirae over its lifetime.
Between the blade and the handle
- Habaki (鎺): A metal collar that wraps the base of the blade. It holds the sword snugly in the saya and keeps the edge from touching the inside of the scabbard. It is the first part to check if a sword feels loose or too tight in its scabbard.
- Seppa (切羽): Thin metal spacers on both sides of the tsuba. They tighten the fit and protect the guard.
- Tsuba (鍔): The hand guard. It protects the hand, balances the sword, and is often the most decorative fitting. Many collectors treat tsuba as art objects in their own right.
The handle (tsuka)
- Tsuka (柄): The handle, built on a wooden core that is carved to fit the tang.
- Same / samegawa (鮫皮): Ray skin glued over the wooden core. Its rough nodules keep the wrap from shifting under grip.
- Tsuka-ito (柄糸): The wrap, traditionally silk or cotton, laid in a diamond pattern over the ray skin. Our article on hilt wrapping goes deeper.
- Menuki (目貫): Small ornaments under the wrap on each side of the handle. They add character and fill the palm for a better grip.
- Fuchi (縁): The metal collar at the guard end of the handle.
- Kashira (頭): The metal cap at the butt end of the handle.
- Mekugi (目釘): A small peg, usually bamboo, that passes through the handle and tang. It is the only thing holding the handle on, so check it before every handling session.
The scabbard (saya)
- Saya (鞘): The scabbard, carved from wood and usually lacquered.
- Koiguchi (鯉口): The mouth of the saya, literally "carp's mouth."
- Kurikata (栗形): The knob on the side of the saya that the cord passes through.
- Sageo (下緒): The cord used to tie the saya to the belt or for display.
- Kojiri (鐺): The end cap or tip of the saya.
How the parts appear on a MoonSwords spec sheet
Every MoonSwords listing breaks a sword down by these parts, so you can compare swords side by side. For example, the Kyūbi Katana lists:
| Spec line | What it tells you |
|---|---|
| Material: Clay-Tempered T10 Steel | The blade steel, differentially hardened for a real hamon |
| Guard (Tsuba): Aged Bronze | The guard material and finish |
| Scabbard (Saya): Solid Wood | The saya construction |
| Handle (Tsuka): Real Rayskin Over Solid Wood | Genuine samegawa over a wooden core |
| Menuki: Aged Bronze | The handle ornament material |
| Blade length 27.95 in (71 cm) | The nagasa, measured from the mune-machi to the tip |
| Handle length 12.6 in (32 cm) | The tsuka length, which affects grip spacing and leverage |
Some listings say "fish skin" instead of "real rayskin." Both are textured skins used under the wrap; real ray skin is the traditional, more premium option. Steel choices are compared in our katana steel guide.
Parts to check when your sword arrives
- Mekugi: Make sure the peg is seated and flush. A missing or loose mekugi is a safety risk.
- Tsuka fit: Hold the handle and gently test for wobble or rattle between the tsuba, seppa, and fuchi.
- Habaki and koiguchi: The sword should click into the saya and stay put when tilted, without needing to much force to draw.
- Edge and kissaki: Inspect under a single light for chips or rolled spots.
- Blade surface: Wipe off shipping oil, then apply a fresh thin coat. Our guide on how to oil your sword blade walks through it.
Frequently asked questions
What is the handle of a katana called?
The handle is called the tsuka. It is a wooden core covered in ray skin (samegawa) and wrapped with cord (tsuka-ito), capped by the fuchi and kashira.
What is the guard on a katana called?
The guard is the tsuba. It sits between the handle and the blade, held in place by thin spacers called seppa.
What is the tip of a katana called?
The tip section is the kissaki. The temper line inside the kissaki is called the bōshi.
What is the scabbard of a katana called?
The scabbard is the saya. Its mouth is the koiguchi, and the cord tied to it is the sageo.
What holds a katana handle on?
A small peg called the mekugi passes through the handle and the tang (nakago). The habaki and a snug fit also keep everything tight.
What is the groove in a katana blade?
The groove is called a hi, most commonly a bō-hi. It lightens the blade without weakening it significantly.
Ready to see these parts in person? Browse our hand-forged Japanese swords, each listed with a full part-by-part spec sheet.