14 Types of Castings

All castings are made by filling a mold with molten metal and then allowing the metal to cool and solidify. The liquid metal is delivered into a mold (usually by a crucible) that contains a negative impression (i.e., a three-dimensional negative image) of the intended shape. The metal is poured into the mold through a hollow channel called a sprue. The mold has a hollow cavity in the shape of the part. The metal and mold are then cooled, and the metal part (the casting) is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.

There are many types of castings which will be discussed individually in the following sections.

All castings have three characteristics in common, which distinguishes them from most machined parts:

1. They have draft angles on some of the surfaces, as shown (image 1).
2. They have fillets and rounds instead of sharp corners, as shown (image 2).
3. Each casting has a sprue (or a sprue mark, if it has been removed by the time it reaches the machine shop) as shown (image 3).
4. In addition, most types of castings will have a parting line mark (image 4), which may be accompanied by a flash or a mismatch (image 5).

The type of mold will have drafts, fillet, radii, flash/mismatch shapes, and method of filling the mold determines the type of casting. 

Image 1

Castings have draft angles so that the sand pattern can be extracted.

Image 2

Castings have fillets and rounds instead of sharp corners, as shown.

Image 3

Each casting has a sprue as shown (or a sprue mark, if it has been removed by the time it reaches the machine shop)

Image 4

Most types of castings will have a parting line mark.

Image 5

Sand Castings may be accompanied by flash or a mismatch.

Derived from Metal casting – Wikipedia. Available online and accessed 4 November 2024, and jjjtrain.com accessed via WayBack machine February 12, 2024.