How trumpets are made

A trumpet is about two meters of brass tube bent twice, and three valves switch in extra lengths of it.

stations: 7
things upstream: 45
raw sources: 18
steps from the ground: 6

The short version

A trumpet is made of brass tubing. Sheet brass is rolled into tubes and drawn smooth, and a flared bell is hammered or spun from a flat disc. The tubes are bent, soldered to piston valves and a bell, then polished and lacquered. A player's buzzing lips set the air column inside vibrating.

Draw the brass tubing

Flat brass is rolled into tubes, seamed, and pulled over a mandrel to make them smooth and uniform. Different leadpipes and tuning slides need different diameters.

Goes in
Brass
Form the bell

A flat disc of brass is shaped over a form into a long, flared bell. The shape of the bell is what makes the missing overtones audible.

Goes in
Brass
Bend the tubes

Tubes are filled to keep them from kinking, bent round formers and cut to fit. Trumpet tubing has been bent twice into a rounded oblong shape since the late 15th century.
Machine the valves

Valve casings and pistons are machined from brass and nickel parts. The three pistons fit so closely that air cannot leak between them.

Goes in
Brass Nickel
Solder the assembly

Bell, tubes, valve block, braces and slides are soldered into one instrument.

Goes in
Solder
Polish and lacquer

The horn is buffed to a mirror shine and then coated with clear lacquer or plated with silver.

Goes in
Silver Lacquer
Test and tune

A tester plays the instrument, and slides are adjusted. First and third valves may carry slides the player can pull out to correct pitch.

End of the lineTrumpet

Worth repeating

Three valves make eight possible combinations but only seven different tubing lengths, since the third valve alone matches the 1-2 combination.
The first valve lowers pitch by a whole step, the second by a half step, and the third by a step and a half.
The trumpet's cylindrical bore distinguishes it from the cornet, which has a conical bore.