Indexing head
（重定向自Dividing head）
![Indexing head and tailstock set up on a milling machine's table.](/Images/godic/202501/09/IndexingHead-Tailstock0735.jpg")
![Cross-section of an indexing head](/Images/godic/202501/09/Indexing_head_cross-section0735.png")
![Interchangeable indexing plates](/Images/godic/202501/09/IndexingPlatesStyle10735.jpg")
![A dividing head mounted on the table of a small milling machine. The direct indexing plate and center are visible facing the camera. An interchangeable indexing plate is visible on the left side.](/Images/godic/202501/09/IndexingHead-SimplePlate0735.jpg")
An indexing head, also known as a dividing head or spiral head, is a specialized tool that allows a workpiece to be circularly indexed; that is, easily and precisely rotated to preset angles or circular divisions. Indexing heads are usually used on the tables of milling machines, but may be used on many other machine tools including drill presses, grinders, and boring machines. Common jobs for a dividing head include machining the flutes of a milling cutter, cutting the teeth of a gear, milling curved slots, or drilling a bolt hole circle around the circumference of a part.