Category Archives: Secondary Operations

Coining


Coining is a closed die forging process, in which pressure is applied on the surface of the forging in order to obtain closer tolerances, smoother surfaces and eliminate draft. Closed die forging is a process in which forging is done by placing the work piece between two shaped dies. This process may be done in hot or cold working conditions, but is predominantly a cold work process. In coining, pressure is applied to a portion or the entire surface of […]

Secondary Operations for Powder Metallurgy Parts


A sintered powder metallurgy (PM) part can be finished or treated just like any other metal part to achieve desired characteristics-corrosion resistance, improve strength ans hardness, surface wear resistance, edge-sharpness relief, porosity sealing, and control of size and surface finish. Plating, coating, deburring, welding, furnace brazing, heat treating, and stem treating are among secondary operations that are used successfully in the process of fabricating finished PM parts. Unlikes parts made using other metal forming processes, powder metallurgy parts can be […]

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Finishing Operations for Forgings


There are two categories of finishing operations: those that produce minor dimensional corrections, and surface treatment processes. Coining, sizing and straightening are commonly used to improve the dimensional accuracy of forgings. When tolerances closer than those that can be economically produced in the forging die are specified, coining and sizing operations are often employed. These processes cause plastic deformation of the forging, either by striking or squeezing a defined area. Coining may be performed either hot or cold, and can […]

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