Fettling - the removal of feeders and excess material from a casting - is the first stage of finishing a casting. The metal removal is often achieved using manual cutting or grinding. However, more emphasis is being placed on automatic fettling, whereby the casting is placed in a machine programmed to remove materials from specific areas. The method of fettling must be taken into account at the initial casting design stage, so that the process is fast and efficient.
Blasting - abrasive particles, such as sand, grit or steel shot, are propelled at high velocity to impact the casting surface to remove surface contaminants. It can also be used to provide a uniform surface finish to castings. Propulsion of the abrasive particles is usually achieved using a centrifuge or compressed air nozzles.
Heat Treatment - the application of heat to a casting to alter the material properties making them suitable for the finished product or for subsequent processing. Heat treatments can be achieved in a number of ways, including induction heating, furnace heating and localised flame heating, amongst others.
Cleaning - non-mechanical removal of surface contaminants. Parts are submerged in different solutions, depending on the requirements of the cleaning process and any subsequent operations. Typical treatments are: molten salt baths used for electrolytic cleaning, acid baths for pickling, chemical cleaning and organic solvent cleaning.
Coating - application of a surface coating aesthetic purposes or to impart resistance to corrosion, wear and erosion. Coating techniques include electroplating, hot dip coatings, hard facing, thermal spraying and painting.