Making habaki

Habaki, a small component placed on the blade as a first one, before seppas, tsuba and handle (tsuka). Its function is to fix the blade in a scabbard (saya). It also creates a smooth transition between the blade and tsuka.
Habaki on the oldest swords, which blades were straight, was usually made of steel. Habaki has later on started to be made of copper, silver and gold. It is also often that habaki is made of copper covered by silver or gold foil. It can be single, so one piece, or also dimerous – formed by two separable pieces.
Although habaki seems to be rather imperceptible component, its making process is not one of the simplest parts while making koshirae. One of the reasons is that this component has to smoothly continue in basic constructional lines of the blade. I consider this as one of the most difficult goals to be achieved. Habaki must be complementary to the blades curves. For example if top of the back of habaki is lower than it should be, the transitions will seem to be a bit snapped off. Of course the same goes for the line of the edge (ha). If it is higher at these points, the blade will start to cause trouble during constructing the handle and scabbard because their width would be at least above standard. As well as the lines of the back and the edge it is also necessary to keep the line of shinogi and the side lines of the back.

Preparation of the semifinished material

We start with 5 to 8 mm thick and 30 mm wide copper piece. We forge it out into intermediate product that has a shape of butterfly. Its centre has the original thickness while the wings are thinner. The centre is placed on the back of nakago. We take scriber and mark the edges of nakago. The wings are than bend over to the sides of the blade. Intermediate product is during bending and fitting repeatedly annealed – warming up and rapid cooling the copper. This softens the material and that allows easier bending and forming the copper. We use a small hammer to slowly fit the habaki on nakago, approximately 3 cm before shoulders (hamachi, munemachi). When habaki fits on the blade, it is necessary to make a little copper wedge that fills the space behind shoulder on the edge (hamachi). This wedge is called machigane. After placing it between connected wings of habaki it is than soldered with silver. Then you place it back on nakago and with small hammer match it until it fits tightly right behind hamachi and munemachi.

Shaping

In this step it is necessary to shape a basic frame of habaki. First of all you use a file to adjust the planes which are in a vertical position to the blade. First the front side (by the shoulders), than the rear side. Both planes should be vertical to the direct axis of the blade in the place where they intersect it. The shape of habaki could be different according to the shape of nakago. Especially with tachi, where nakago is markedly bent, the beholder could get the impression, that habaki is getting narrow in direction to the back. The next step would be adjusting the lines which continuing on curvature of the edge and the back of the blade. I have mentioned this process above. Now comes filing of the planes, which in the end form the sides of this component. If habaki has a rib (shinogi), it will smoothly follow the rib of the blade. We use files for such work and habaki is put on adjusted wooden plate fixed to the worktop. The final shaping is done by smooth files, but that is already aesthetic matter

Decorating

The planes could be smoothed, or they can have parallel filing marks. Another option can be adding sideways marks by special scratcher, which create an impression of raindrops. There are many ways of decorating like this. Another way would be already mentioned covering the copper habaki by silver or gold foil. I have just seen the process. I have never tried it, so I am not going to describe the whole process. Simply said, it is covering the outside planes with gold foil, or rather very thin sheetmetal. This laps over the edges of habaki. We bend these side laps and then slick them down by steel needle. After that it is again possible to decorate it by mechanical marks.
Very interesting is habaki formed by two parts. Its making process is a bit more complicated. We cut out and file a recessing in the rear side of habaki; a bit wider than nakago. Copper sheetmetal ring is than fitted in this space. It is wrought to accurately fill the original space before cutting out the shoulder. With that we use a silver to solder wings, which are then also wrought by file to the final shape. These wings form the outer sides of habaki and they are much shorter than the inner side. I have heard couple of different theories about dimerous habaki and its function. For example that outer wings spring so the sword holds better in the scabbard. In fact the wings adjoin tightly to the inner part of habaki, so I consider this as an unsubstantiated theory. I think it is no more than simply aesthetic matter. As I see it, it is nice version that rapidly increases craftsmans pretensions and that reasonably rises the cost of this component.
Making habaki is relatively hard. Yet I consider it one of the most interesting. In Japan there are specialists devoted to making this component only.