A surgical cutting tool (22) includes an elongated shaft (30) and a cutting head (38). The shaft defines a coupling portion (36) terminating at a proximal end (62) of the shaft, a stem portion (34), and a distal portion (32). The stem portion defines a central axis A. The coupling portion optionally defines a deflection surface (72a, 72b) positioned oblique with respect to the central axis and connected with a first driven surface (76a) and a second driven surface (74a). Upon insertion into a drive chuck (40) with drive pins (44a, 44b), the deflection surface promotes self-alignment of the cutting tool and the drive chuck.
