Most retain casting sprues, and the suspension loops and resonators filled with metal during the casting process.
Detached casting sprues were found, which could have been trimmed off suspension loops or other cast artifacts.
Production tools and debris have also been found and include crucibles, casting sprues, prills, bell clusters, and failed bells.
Casting sprues are remnants from the lost-wax casting process and the means by which the metal entered the mold to form the bell.
The failed bells and casting sprues were then put into the crucibles to recycle them into new objects.
A small number of patients have a true 'refractory sprue'.
Other bells were miscast or retained the casting sprues, which may indicate local production.
As noted in the four intact crucibles, the lumps of metal were composed of casting sprues and failed bells.
