How a Trumpet is Made
Manufacturing the valve casings
The valve casings represent the heart of the trumpet
The tube which moves the piston up and down is called a valve casing. The valve casing is the key component which acts as a switch, changing the pitch of the note-in a sense, it is the heart of the trumpet. All production work for the valve casings must meet the highest standards of precision.
1. Machining and broaching
Holes are drilled in precise locations.
2. Brazing process
The components of the valve casing are fitted into a special jig and then passed through a kiln to braze them together in precise fashion.
Note: Brazing is a method for joining-like soldering-but uses a much higher melting point and produces extremely strong joints.
The interior of the brazed valve casing is precisely machined using a lathe. This machining work is a critical process in the production of instruments that use pistons.
The gap between the side of the valve casing and the piston is defined as 10 microns. This represents such high precision that a single human hair in the gap will stop the piston from moving.
*10 microns (0.01 mm) is approximately one-tenth the thickness of a single strand of human hair.