REAMER

The reamer is a Cutting tool intended for Reaming, that is, to enlarge and to To gauge precisely an existing hole. Comparable to a Drill bit in appearance, it is distinguished by its cutting mode: while the drill bit cuts only at its tip, the reamer cuts along its entire Length, by its lateral edges. It therefore does not create the hole, but perfects its diameter, straightness, and surface finish with great precision. Cylindrical or conical in shape, it is used by hand, fitted with a handle, or mounted on a machine (Drill, Lathe, milling machine). In watchmaking, the reamer is used to adjust jewel, canon pinion, or shaft seats to their final size, where precision is measured in microns. The quality of the reaming — and thus of the reamer and its sharpening — determines the set and fit of the assembled parts: a seat that is too wide creates play, while one that is too tight prevents assembly.