Abstract: A work supporting device for secondary treatment of workpieces by hand has a base which is affixed to a bench and defines a vertical pivot axis for a support serving to mount a chuck carrier for rotation about a first horizontal axis. The chuck in the carrier can support a work holder so as to allow for angular movements of the work holder about a second horizontal axis extending at right angles to the first horizontal axis. The support can be clamped to the base and the carrier can be simultaneously clamped to the support by a linkage having a pivot member mounted in the base for rotation about the vertical axis, a lever which is pivotably connected to the upper end portion of the pivot member, and a link which is pivotably connected to the lever and to the carrier so that it can turn about the first horizontal axis. The lever can be pivoted by a rotary eccentric through the medium of a knob.