With the improvement of machining precision, in order to reduce the positioning error, improving the machining precision requires higher precision of the fixture manufacturing precision. The precision of positioning hole spacing of the fixture is up to ±5 m, the verticality of the fixture supporting surface is up to 0.01mm/300mm, and the parallelism is up to 0.01mm/500mm. The 4m long and 2m wide hole series combined welding fixture platform made by German demmeler (demmeler) company has the contour error of ± 0.03mm. The parallelism and perpendicularity of the precision flat nose pliers are within 5 ° m; The positioning accuracy of repeated fixture installation is up to ±5 m; The repeatable positioning accuracy of EROWA flexible fixture in Switzerland is up to 2 ~ 5 m. The precision of jig has been improved to micron level, the world famous jig manufacturing companies are precision machinery manufacturing enterprises. Indeed, in order to adapt to the needs and economy of different industries, the clip has different models, as well as different grades of precision standards to choose from.