Mekugi: The Essential Bamboo Peg Fixing Katana Tsuka and Nakago

When studying Japanese nihonto fittings and display‑oriented katana for collection and anime‑themed display, most hobbyists focus on tsuba handguard or tsuka‑ito wrapping. Yet one indispensable fastener holds tsuka and nakago tightly together: mekugi, the traditional peg designed to lock sword handle and blade tang.

Mekugi works like a sturdy pin that firmly secures the tsuka handle to the nakago tang, stopping the blade from slipping loose during wielding. The matching holes drilled through handle and tang are named oyatsubu, also known as mekugi-ana. To disassemble the sword for maintenance, you only need to pull out the mekugi peg and slide the nakago out of the wooden tsuka core. Standard bamboo mekugi comes in cylindrical shape with a diameter of 5 to 7 millimeters.

Metal mekugi existed in ancient times, but they were rarely used for combat swords. Hard battle impact causes plastic deformation on metal pegs, making them stuck permanently inside the holes and impossible to extract later. Winter-solstice bamboo dried for three years and soaked in camellia or rapeseed oil is the premium raw material for mekugi, with boosted toughness and elasticity. Coal bamboo, aged bamboo smoked black in ancient attics for hundreds of years, performs even better than regular bamboo for peg production.

The placement of mekugi-ana holes shifted drastically across Japanese eras. During the Nara period, jokoto swords featured mekugi-ana near the tail end of nakago, a trait visible on national treasure blades like Suiryuken water dragon sword. After anti-tachi styles emerged, peg holes were drilled closer to the chi section, centered horizontally on most okoto period tangs.

Besides the classic bamboo mekugi locking method, ancient swordsmiths created four alternative practical solutions to fasten tsuka assemblies securely.

The wood chip wrapped rope type reserves extended tang length during forging. Matching wood chips are fixed on both sides of nakago, then wrapped tight with anti-slip cord. This method delivers stable assembly with low production costs.

The glue-filling fastening coats the entire tang surface with high-strength adhesive, then inserts the pre-drilled wooden handle directly onto the nakago. This technique relies heavily on glue quality; inferior adhesive leads to loose handles over time, mostly seen on short-length swords.

The eye nail fixation originated from ancient Chinese sword craft and was refined in Japan. It allows easy disassembly for blade inspection and fitting replacement, yet the metal nails wear quickly under heavy use and demand frequent repair.

The fixed tail rivet method forges extra length on the nakago end. After installing the handle, the extended tang tail is heated red-hot and hammered flat to lock the tsuka permanently. Often paired with mekugi pegs for maximum stability, its major downside is non-detachable assembly — the wooden handle has to be destroyed to take the sword apart.

For modern sword collectors, mastering mekugi knowledge and historical fastening techniques helps judge the craftsmanship and authenticity of replica nihonto. When exploring katana component anatomy, examining mekugi installation and tang hole layout is a key evaluation standard. You may read museum documentation covering traditional nakago‑tsuka mounting and disassembly practices for further reference.