The socket of a clarinet can crack for many reasons, but it’s usually because of improper handling or tenon fit. Small cracks in the socket can be repaired by gluing or carbon fiber banding, but when the cracks are too big, a socket graft or socket replacement is necessary.
The procedure starts by finding a donor clarinet or constructing a new piece to be used in place of the damaged part. The broken socket is turned on a lathe to accept the new part, and the part is glued onto the previously broken clarinet. This is a permanent fix, and because the bore of the clarinet remains intact, the player won’t notice any difference in sound or tuning.