Abstract: A fixture attachable to the table of a machine for holding a part to be machined in operative relationship with the tool of the machine. The fixture comprises a base plate having a locator pin extending from its bottom surface and adapted to fit within an aperture in the machine table to locate the fixture on the table. A plurality of sector-shaped support pads are secured to the top surface of the base plate in evenly-spaced radial relation, adjoining margins of the pads being spaced to leave therebetween radially-extending portions of the top surface of the base plate. Locator blocks are adjustable to various positions radially of said top surface portions, each block having a locating pin, the pins cooperating to engage either the inside or outside peripheral surface of a circular part or workpiece to locate the same. Clamps are securable at various radial positions on the support pads to clamp the workpiece and hold it against axial separation from the fixture base.