Lead screw used in analytical instrument

The utility model discloses a lead screw for the inside of an analytical instrument, which belongs to the technical field of lead screws and comprises a lead screw body, connecting rods are fixed at two ends of the lead screw body, a mounting rod is arranged at one end of each connecting rod, and a fastener component for fastening the connecting rods is arranged on the outer wall of each mounting rod. The buckle assembly comprises a sliding sleeve slidably mounted on the outer wall of the mounting rod, an extrusion groove is formed in the inner side of the sliding sleeve, a release groove is formed in the position, located on one side of the extrusion groove, of the inner side of the sliding sleeve and communicates with the extrusion groove, and a connecting groove matched with the connecting rod is formed in one side of the mounting rod; an arc-shaped limiting through groove is formed in the outer wall of the mounting rod and located in the release groove, a ball block is placed in the arc-shaped limiting th