Machined castings refer to cast metal parts that have undergone additional machining operations after being cast. These additional machining processes can include milling, drilling, turning, grinding, and any other necessary operations to achieve the desired dimensions, tolerances, and surface finish.

The process of machining castings involves the following steps:

1. Casting production: The castings are produced using various casting methods such as sand casting, investment casting, or die casting. These processes involve pouring molten metal into a mold and allowing it to solidify and take the shape of the mold.
2. Casting cleaning: After the castings have cooled and solidified, they are removed from the mold and undergo cleaning processes to remove any residual sand, gating systems, or other casting debris.
3. Machining setup: Once cleaned, the castings are set up on a machining tool, such as a lathe, milling machine, or CNC machine. Fixtures or clamps may be used to hold the casting securely in place during machining.
4. Machining operations: The casting then undergoes various machining operations to shape it to the required dimensions. This can include removing excess material, creating features such as holes or threads, and achieving the desired surface finish.
5. Quality control: During and after machining, the castings undergo quality control inspections to ensure they meet the specified dimensions and tolerances. This can involve the use of measuring instruments such as calipers, micrometers, or coordinate measuring machines.
6. Finishing operations: Once the machining operations are complete, additional finishing processes such as deburring, polishing, or coating may be applied to enhance the appearance and functionality of the machined castings.

Machined castings are commonly used in industries such as automotive, aerospace, machinery, and construction. They offer the advantage of combining the versatility and intricate shapes achievable through casting processes with the precision and accuracy achievable through machining operations. This allows for the production of complex parts with tight tolerances and high-quality surface finishes.