Pipette assembly that includes a pipette device, a pipette tip, and a leaf spring coupling device coupling the tip to the pipette device, the coupling device includes a plurality of circumferentially disposed elements or segments in the form of flexible leaf springs with stabilizer plateaus used to retain a pipette tip to the coupler and prevent the pipette tip from rocking on the coupler and a distal elastomeric element, such as an O-ring, and the pipette tip includes dual complemental working surfaces in the pipette tip to provide precise control of an axial coupled position defined as an axial distance from a distally facing axial stop surface of the pipette tip coupler to the end of the pipette tip that contacts liquid when the pipette tip coupler and disposable pipette tip are in a coupled configuration.