Abstract: In a shaft seal of resiliently deformable elastomeric material and which comprises a seal body of annular form having a longitudinal axis and having an annular front face, an annular rear face, an annular inner face, and an annular outer face, and a frusto-conical sealing flange extending outwardly and forwardly from the front face of the seal body adjacent the inner face thereof, there can be a tendency when the seal is in use with the seal body resiliently deformably mounted on a rotatable shaft and with the sealing flange in bearing contact with a fixed wall having an opening through which the shaft is disposed for the seal operatively to move axially radially relative to the shaft particularly when the shaft is rotated at high speed.