Drill bit rings are set to a common distance from the point to the back of the ring, thereby allowing a controlled drilling depth. The quality of these rings is as critical as the consistency of drill bit attributes because they can equally affect drill bit performance. |
Other issues:
Rings that fit too tightly may crack and loosen catastrophically.
Rings that have protruding material (“flash”) on the inside diameter may cause improper seating of the drill bit in the collet (of the spindle) or may prevent the drill bit from being properly inserted into the tool pod or cassette, resulting in destructive tool change problems.
Rings have specific color codes assigned to each size and maybe marked with size, diameter, and design or series number. Rings may be either machined or mold-injected.
Drill rings are normally injection molded though machined rings are superior because of their consistency and quality, though their cost is prohibitive for most applications.