Casting

Advantages

Once cooled, the sand is broken up, leaving the casting.  From this point, depending on the casting, machining, cleaning, or coating may take place.

In this manufacturing method, the pattern is not the mold, but rather the tool to make the mold.  Using the match plate, a flask is placed on either side (the Cope and the Drag) and filled with sand.   The hard sand is then taken off the pattern, and the pattern is removed.  Whats left is a 2 part sand mold with a negative of the pattern.  The 2 halves of the sand mold are then put back together creating a pattern shaped cavity.  Metal is the poured into the cavity creating the casting. 

The first step in casting is creating the pattern.  The pattern is a approximate duplicate of what the finished part will look like.  The pattern will often be mounted to a board (called a match plate), and have allowance for any cores (hollow parts of the casting).  It will also have an identifiable parting line, draft angles, and machining allowance if necessary.  One of the most crucial parts of the match plate is its gating system.  The gating system is network of connected channels that deliver the molten metal to the mold cavities.  Parts of the gating system include gating, runners, wells, sprues, risers and filters.  Creating these parts is a skill in itself, taking into consideration the different characteristics of the metal being poured.

Casting can be used to create metal parts that are either too complex for fabrication, or if a large number of parts are needed.  Casting is one of the oldest forms of manufacturing (civilizations have been casting for over 6000 years).

Casting is act of pouring molten metal into a hollow cavity in the mold. The mold is then cooled until the metal has solidified, leaving a finished part.