A coupling mechanism designed to removably attach a reamer to the distal end of a spindle or shaft is disclosed. The coupling comprises a collar having an annular sidewall that defines a collar throughbore, the collar annular sidewall comprising a plurality of spaced part first slots that at least partially extend through the sidewall and a shank disposed within the collar throughbore. The shank is constructed with a shank annular sidewall in which a plurality of spaced apart second slots at least partially extend therethrough. A bias member that provides a bias force in a distal direction that acts on the collar is incorporated within the mechanism. The collar is capable of sliding in an axial direction such that the first and second slots become aligned to secure the cross bar of a reamer therein.