Flask (foundry)
Encyclopedia
A flask is a type of tooling used to contain a mold in metal casting. A flask has only sides, and no top or bottom, and forms a frame around the mold, which is typically made of molding sand. The shape of a flask may be square, rectangular, round or any convenient shape. A flask can be any size so long as it is larger than the pattern
being used to make the sand mold. Flasks are commonly made of steel
, aluminum or even wood. A simple flask has two parts, the cope
and the drag
, and more elaborate flasks may have three or even four parts.
. The bars help support the sand through the molding and pouring operation.
Flasks are designed with an alignment or registration feature so that the two flasks can be aligned to one another to insure a casting
can be more dimensionally accurate.
Flasks will usually have handles or trunnions designed into their construction which assist in handling the flasks with cranes
or other lifting machinery.
Some flasks are used to form a mold and they are removed before pouring the casting so another mold can be made. Other flasks are designed to contain the mold through the pouring operation, and then the casting is shaken out of the mold. The flasks are then used again and again.
Flasks are usually (though not always) the property of the foundry making the casting. The number of available flasks of a given size can be a limiting factor in the overall production rate.
Pattern
A pattern, from the French patron, is a type of theme of recurring events or objects, sometimes referred to as elements of a set of objects.These elements repeat in a predictable manner...
being used to make the sand mold. Flasks are commonly made of steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
, aluminum or even wood. A simple flask has two parts, the cope
Cope and drag
In foundry work, the terms cope and drag refer respectively to the upper and lower parts of a two-part casting flask, used in sand casting. The flask is a wood or metal frame, which contains the molding sand, providing support to the sand as the metal is poured into the mold...
and the drag
Cope and drag
In foundry work, the terms cope and drag refer respectively to the upper and lower parts of a two-part casting flask, used in sand casting. The flask is a wood or metal frame, which contains the molding sand, providing support to the sand as the metal is poured into the mold...
, and more elaborate flasks may have three or even four parts.
Flask Design
Flasks are often designed with bars which extend span two opposite sides. The bars act as reinforcement to the molding sand which is relatively weak in tensile strengthTensile strength
Ultimate tensile strength , often shortened to tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract...
. The bars help support the sand through the molding and pouring operation.
Flasks are designed with an alignment or registration feature so that the two flasks can be aligned to one another to insure a casting
Casting
In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process...
can be more dimensionally accurate.
Flasks will usually have handles or trunnions designed into their construction which assist in handling the flasks with cranes
Crane (machine)
A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of...
or other lifting machinery.
Some flasks are used to form a mold and they are removed before pouring the casting so another mold can be made. Other flasks are designed to contain the mold through the pouring operation, and then the casting is shaken out of the mold. The flasks are then used again and again.
Flasks are usually (though not always) the property of the foundry making the casting. The number of available flasks of a given size can be a limiting factor in the overall production rate.