When machining precision parts of small and medium-sized batches of workpieces, a combination fixture can be used for clamping. The combination fixture has the characteristics of disassembly and reassembly. Therefore, the combination fixture is a reusable special fixture system. However, there are many links between the components of the combined fixture, and the rigidity and accuracy of the fixture are inferior to other fixtures. Generally, when using combined fixtures, the machining dimensional accuracy can only reach IT8 ~ IT9 level. Secondly, the first investment using a combination fixture is generally bulky, and there are also inconveniences such as inconvenience in chip removal.

At present, commonly used combined fixture systems include slot-based combined fixture systems and hole-based combined fixture systems.