What Are Dies and Moulds?

What Are Dies and Moulds?

Many of the things we see and use every day are made with dies or moulds.

Dies are special tools that shape and cut metal and plastic by pressure. If you have ever watched as star-shaped biscuits were punched out of a sheet of dough by a biscuit cutter, you have seen a very simple type of die in action.

Moulds are special tools used to shape materials in liquid form.

Metal, plastic, or any other material, is poured or forced into the cavity of the mould and allowed to solidify. A mould of gelatine is an example of a very simple type of mould.

Dies are used in industry to make parts with shapes that are hard to produce with other machine tools. Examples are parts for cars, such as bonnets and bumpers. Moulds are also used in industry to make parts, such as refrigerator-door handles, radio casings, and some car radiator grilles.

To make parts like these by regular machine operations of cutting, grinding, and drilling would take a great deal of time and much material would be wasted. With dies, they can be stamped out like biscuits. The same holds true for moulds.

In addition to producing difficult shapes, dies and moulds are good for the fast production of large numbers of identical parts. The parts that die and mouldsmould turn out usually need no finishing. Difficult parts may require a little grinding or polishing to remove seams on moulded parts and rough edges on die-stamped parts.

Moulds and dies in general are made in two halves. When brought together they will make the shape of the part. Moulds form the outside shape only. Dies can form both inside and outside shapes.

Did you know that dies were used as long ago as 650 B.C. 

, when

Greek metalworkers made silver coins with them? The coins were produced by pounding metal into a pattern cut into a harder metal block.