TOKYO Teshigoto

Rustic tools that support delicate work

Knowing the tools

There are many types of hammers in the workshop.

You can feel the strength of a metal craft workshop

“Metalworking” is a craft that uses metal as a material and is crafted by various techniques. The main materials of metalworking are gold (kogane), silver (shirogane), copper (akane), tin (aogane), iron’s (kurogane) “five metal (gokin)” and metal alloy of these metals. The techniques of crafting are mainly divided into engraving, casting metal, and forged metal. The Nagasawa Seisakusho which we cover this time, is a forged gold factory that mainly handles copper and brass. Forging metal is a technique to make shapes using the feature of metal by “stretching and spreading by beating” but the metal itself is hard so it has to be soften by heating and beating many times over and over. The workshop at Nagasawa Seisakusho has plentiful of tools lined up such as wooden hammers and hammers for beating, burner to anneal and tools for punching metals. The sound of a hammer beating a metal and flame that comes out of the burner gives a strong impression rather than a delicate impression to the workshop.
We were introduced many tools by going after the process of copper-made tea pot, one of Nagasawa Seisakusho’s main products.

A machine which is called “ketobashi (left photo)” is used in order to die cut and mold efficiently. Metal molds (right photo) are attached to the “Ketobashi.”

Cut the copper plate to each part

Cut a thick copper plate into a perfect circle shape with “shears (kanabasami)” that is fixed to a wooden board. Toshihisa Nagasawa, who is the 3rd Generation of Nagasawa Seisakusho and who demonstrated the copper plate cutting gave an explanation about the process. “We often use machines to cut out the shapes.” His technique of cutting out curvy shape is perfect. The cut copper plate is heated by using a burner until the copper plate turns red. Since copper has a high melting point, annealing is done by a considerably high temperature. Natural cooling produces an oxide film on the surface. A beautiful skin appears after immersing in a pool of diluted sulfuric acid and removing by doing the “acid wash.”

Cut a big copper plate with “shears (kanabasami).”

By annealing with a burner, the metal becomes soft and easy to create solid shapes.

Beating by creating shapes and beating by adding patterns

The annealed copper is made into a shape of a teapot and pour spout by using a wooden hammer and a hammer. This process is called “shaping (tsuiki)” or “squeezing (shibori).” The tools that are used in this process are, “wooden hammer”, “hammer”, “metal stick (ategane)” and a “table” which is called a “beehive.” The shape is made by placing the copper plate on the “table” that looks like a beehive and insert the “metal stick” in the hole so the copper plate stays still. Then beat the copper plate with a “wooden hammer” or a “hammer.” The copper gains strength and becomes stronger by being beaten. The process of making in three-dimensional from by handwork is spectacular but it takes a lot of time. This process is often done by machinery. This time we were able to see the process of making the patterns by beating. The patterns which is called “tsuchime” is made by using the head side of a “hammer.” Patterns such as “arare moyou”, “nashiji” and “gozame” are designed on the surface of the teapot.

A piece of flat copper plate turns into a copper-made teapot by using the technique of forged metal.

Variety shapes of “metal sticks.” Select which “metal stick” to use depending on the shape and the size of the place where you beat.

Insert the “metal stick” to a table that is called a “beehive” to hold it still. This kind of process is done with a “wooden hammer.”

Use a dedicated “metal stick” to generate “smoothness.”

When making the pour spout, “wooden hammer” and “hammer” is used to make it in three-dimensional shape just like when making the body part. A “metal stick” that is used for the pour spout has a delicate similar shape to a pour spout. A piece of copper plate turns into a pour spout by using the curvy and pointed part of the “metal stick.” You can tell how good Nagasawa Seisakusho’s teapots could perform “smoothness” when pouring. This “smoothness” is generated by beating the curves of the pour spout.

Master using the “metal stick” to make a pour spout that produces “smoothness.”

Solder the pour spout to the body part of the teapot

After finish making the body, pour spout and the patterns, these parts are attached with solder. The molten solder wraps around the joint of the body and the pour spout very smoothly. This shows the quality of the forged metal technique is high that the body and the curve part of the pour spout matched perfectly. It also explains that all the neat work was done with care.

Use a “ketobashi” to make holes in the body part of the teapot (left photo). Attach little screw to the hole (right photo).

Attach screws to the holes and slightly tilt the head of the screw to the outside. (left photo). Attach the pour spout to the tilted screw as if hooked (right photo).

Once after annealing with burner, hydrochloric acid is used as a bond (left photo). When the yarn solder is brought close to the joint while heating with a burner, the molten solder wraps around by blending in to the joint (right photo).

A fine delicate looking teapot made from rustic tools

The first impression of the workshop is powerful and rustic. The tools can withstand powerful work in a workshop that processes metal. The sounds that can be heard in the workshop are the beating sound of a hammer, “ketobashi” a sound which is made when punching a hole through a metal, and the sound of flame that comes out from the burner. Every sound is powerful. However, it is wondrous how that beautiful shaped teapot with delicate patterns was made by using all those tools.

Nagasawa Seisakusho’s main product is copper-made teapot. They have round shaped and a barrel shaped type of teapot.

Toshihisa Nagasawa, the 3rd generation of Nagasawa Seisakusho. His pursue towards beauty and functionality is beyond “ultimate.”