root fillet

root fillet

[′rüt ‚fil·ət]
(design engineering)
The rounded corner at the angle of a gear tooth flank and the bottom land.
References in periodicals archive ?
Most of these studies address two major issues: the geometry of the tooth root fillet (Hebbal et al., 2009) and the rim thickness (Nan & Zang, 2008).
If a root fillet on a gear, for instance, had only partial coverage, the flat or undimpled areas now would carry higher tensile stresses and premature gear failure is possible.
This stress concentration at the root is further amplified by the second fact--the absence of root fillets.