Skip the scroll — read the text

seven acts, from raw steel to finished object

This page draws a katana blade as you scroll: the page position is the temperature of the steel, from the furnace to the finished object. Each of the seven stages is announced and described in text as it is reached. The complete text, with sources, is also available at the end of the page — the first link on this page skips there directly.

Computing the blade

I the bloom It never melted. Reduced for three days and three nights in a clay furnace, the steel leaves as a spongy mass — never as a liquid.

II the folding Heat, strike, fold. Each fold doubles the layers.

III the shaping 32,768 layers. Fifteen folds, and no further: every pass through the fire burns off carbon, and steel without carbon will not hold an edge.

IV the clay Draw the line. Thick along the spine, thin along the edge — then left to dry: applied wet, it would lift in the fire. Move the cursor along the blade.

V the quench 800 °C, then water. The smith reads the heat by colour, not from a dial. The bare edge goes out first; the spine, under its clay, holds a second longer. From that second come the hardness, the line, and the curve.

VI the polish Polishing creates nothing. A succession of stones and several weeks, until the scratches are finer than the grain of the steel. What is visible then is no longer the polish — it is the material.

VII the mounting The mark disappears beneath the hilt. The collar, the wood, the braid — and a bamboo peg, because bamboo bends before it breaks, and its fibres still hold once it has given way.

the object This line is yours. The blade entered the water straight and came out curved — no one bent it. And the hamon shown here is the one you traced: it exists on no other blade.

The Blade

A katana blade, generated in code and never loaded from a file. Scrolling is not a descent through a page: it is the temperature of the steel.

What this site is

A blade being made. Seven acts, in the order of the craft: the bloom of steel, the folding, the shaping, the clay, the quench, the polish, the mounting. The page descends, the steel cools, and the object is completed. The site ends when the blade is finished — there is nothing after, by design: this is a record of work, not of a weapon.

Nothing on this page was loaded

No 3D model, no texture, no image, no sound. The geometry of the blade is computed from its measurements; the colour of hot steel is that of a black body at its temperature; the hardening line is a field traced by the visitor. The blade is not downloaded, it is computed; the hardening line is not painted, it is solved; the curvature is not animated, it is derived. There is nothing here but causes and their consequences, executed.

The measurements are those of a real blade

Length 702 mm, width 30 mm at the base and 20 at the yokote, point of 36 mm, tang of 201 mm. They come from a certified blade. The engraving on the tang is not a signature: it is a tool mark. Inscribing a master's name on a generated piece would fabricate an attribution, and that is not ours to do.

Nomenclature

Hover the finished blade and its mounting: each part answers with its name. The same list, for reading —

kissaki 切先
The point. Its geometry is a separate surface — the polish changes direction across it.
yokote 横手
The line where the point begins; the finish turns to run crosswise beyond it.
mune 棟
The back of the blade, raised to a shallow roof.
shinogi 鎬
The longitudinal ridge, set at seven-tenths of the width from the edge.
shinogi-ji 鎬地
The flat between ridge and back, burnished to a near mirror.
jihada 地肌
The grain of the folded steel, revealed — not drawn — by the stones.
hamon 刃文
The hardening line, where the clay lay thin. On this blade it follows the line you drew.
ha 刃
The hardened edge. Approach it and the blade rolls to present its back — the etiquette of handling.
boshi 帽子
The temper line as it enters the point and turns back.
nakago 茎
The tang. Left unpolished, by rule: it is the record the polish must never touch.
mei 銘
The engraving. A tool mark, not a signature — naming a master here would fabricate an attribution.
habaki 鎺
The collar that seats the blade in its mount, filed to this blade alone.
tsuba 鍔
The guard: hammered iron, the work of a specialist — not the smith.
fuchi 縁
The collar of the hilt; the wrap is braided between it and the pommel.
tsuka-ito 柄糸
The silk wrap, each crossing folded; the white ray skin shows in the open diamonds.
kashira 頭
The pommel, set before the braid — the final knot is tied across it.
mekugi 目釘
The single bamboo peg. Pull it, and blade and mount come apart by design.

What is verified, and what is not

Every step and every temperature shown here was checked against a source before being written: the direct-reduction furnace and the steel that never melts, the limit of folding and the carbon it burns, the 750–850 °C of the quench read by colour, martensite at the edge and pearlite at the spine, the polisher's succession of stones. Where no source was found, nothing was claimed.

Sources