== Tuning ==
While the profile of the bell can be adjusted to provide bells that
are very good sounding, bells that ring together, especially bells intended to be members of a chime or carillon instrument, are machine tuned after casting.
The tuning process generally involves a lathe. Horizontal shop lathes can be used for small bells, but large vertical engine lathes are used for large bells. This process always involves the removal of material and so it is an irreversible process. The risk of re-tuning valuable bells often does not justify the perceived benefits. Tuning individual partials of a bell is not as simple as tuning individual strings on a guitar for example. When one removes material from one area of the bell's profile, it may raise some partials while it lowers others. The tuner must be familiar with how each partial will react to the locations of cuts for the profile of a given bell.