Appearance
Surface Quality: The fixture surface must be free of casting defects such as cracks, sand holes, and porosity, as well as obvious scratches and dents. Otherwise, the fixture's performance may be affected, or the workpiece surface may be scratched.
Coating and Protection: If the fixture has a coating, such as paint or electroplating, the coating must be uniform and firm, without peeling or flaking, to provide good rust prevention and aesthetics.
Parts Integrity: All components of the fixture, such as bolts, nuts, locating pins, and clamping devices, must be complete. No missing or damaged parts should be found to avoid affecting the normal use of the fixture.
Regarding dimensional accuracy
Critical dimensions: Key dimensions of the fixture related to workpiece positioning, clamping, and connection with machining equipment must be within the tolerance range required by the design. Examples include the diameter of the locating pin, the flatness of the locating surface, and the positional accuracy of the fixture mounting holes.
Overall dimensions: The overall dimensions of the fixture must conform to the specifications in the design drawings to ensure smooth installation on the machining equipment and to prevent interference with other components.
Regarding positional accuracy
Positioning accuracy: The positioning elements of the fixture, such as locating pins and blocks, must ensure the workpiece's positional accuracy within the fixture. That is, after clamping, the workpiece's positional deviation relative to the cutting tool or machining equipment must be within acceptable limits to ensure the dimensional and positional accuracy of the machined workpiece.
Clamping positional accuracy: When clamping the workpiece, the clamping device must not cause excessive deformation and must ensure that the workpiece does not shift during machining. For example, the clamping point must be appropriately positioned, and the clamping force must be uniform to avoid affecting machining accuracy due to improper clamping.
Assembly positional accuracy: The relative positional accuracy of the assembled components on the fixture must meet requirements. This includes the positional relationship between the positioning and clamping elements, and the perpendicularity and parallelism between different positioning surfaces.
