This patent is for a clamping mechanism for a two wheel panel dolly which is operated by turning a handle attached to the wheel axle. A threaded section of the axle is engaged with a threaded base clamp so that axle rotation drives the clamp along the axle to firmly grip a panel between the driven clamp and a the face of second clamp. Clamps are configured with different spacing between faces on opposite sides of the axle so that a wide range of panel widths can be accommodated with a relatively short clamping travel distance.