How a Bassoon is Made
How the Bocal is Made

Conical tube made from flat metal sheet

Let's take a look at the traditional technique for making the bocal. First the sheet is prepared, cut into the shape of a trapezium. Then it is bent inwards from both sides, and solder applied to the join. When heat is applied the solder melts, and binds the two sides.
Next, the shape is squashed so that the seam is flattened, and the tube is then pulled lengthways to produce a narrow, conical tube as per the design. After that, a rod is inserted to prevent the tube from being crushed, and the stamp is engraved.

From rear, the sheet, after applying solder, after the seam is flattened, after stretching

The stamp is engraved carefully on each bocal, one by one

The clearly engraved stamp (finished product)

Curve formed in two stages

The conical tube used to make the bocal is heated using a burner to make the metal soft, then a low-temperature solder is applied to the interior and the tube is bent. As the bocal is curved in two directions, the curves are formed in two stages.