bezel(n = noun.artifact) - a sloping edge on a cutting tool;
is a kind of edge

   The rim which encompasses and fastens a jewel or other object, as the crystal of a watch, in the cavity in which it is set. [1913 Webster]

bezel, n.
1 the sloped edge of a chisel.
2 the oblique faces of a cut gem.
3 a a groove holding a watch-glass or gem. b a rim holding a glass etc. cover.

Etymology:
OF besel (unrecorded: cf. F b{eacute}seau, bizeau) of unkn. orig.