In 1847, Theobald Boehm created the silver cylindrical bored body with parobolic tapered headjoint. This new design used larger tone holes which necessitated an open key for each tone hole. Previous designs had left open holes on the body to be covered directly by the player’s fingers. Boehm increased the hole size to add to the projection of the instrument and more carefully regulate the intonation of the scale.

In 1849, Giulio Briccialdi had Rudall and Rose of London build an instrument with the thumb key design which remains standard to this day.

Boehm’s original design called for an open G# mechanism (still used today by some prominent players such as William Bennett and Clement Barone.) However, the duplicate closed G# key has been in use since Boehm changed his design in 1847. This was due to the fact that French players particularly were unwilling to adapt their technique to the open G#. Even when Louis Dorus adopted Boehm’s earlier 1832 flute at the Paris Conservatory, it was only with the adaptation of the “Dorus G# mechanism” to facilitate a closed G# key.