In this method, the type was made by punching a letter-shaped cavity in a matrix made of some soft metal (typically copper). Then this matrix would be held in the lower part of the mould, the upper part would close on it, and molten type metal would be poured into the cavity. Using the hand mould, the printer could quickly make any additional type he might need.
In injection moulding, hand moulds refer to simple moulds that have no provision for heat, cooling, or ejection. This means when a hand mould is cycled universal heating plates are required to warm the moulds and the moulds must be removed after each cycle to remove the mouldings. This drastically increases the cycle time, which limits it to short runs, but to offset this is the low cost of the mould. They are usually single cavity moulds, but may be multi-cavity if the moulding is quite small. They are usually only of a two or three plate design because of the simplicity of the parts. If only a short run is required then the moulds may be made from aluminum or brass, but if more parts are required then they are made from conventional steels.
Hand cast bullets remain popular with the handloading, muzzleloading and small custom ammunition loading communities. In a tradition dating back to the beginning of firearms, molds matched to the bore (and the chamber for breech loading weapons) are custom made for each weapon. Anywhere from one to six cavities are carved into the molding block, along with appropriate gates and sprues. As the blocks are now usually made out of aluminum, which does not allow lead alloys to stick, only a small amount of parting compound is needed.
- Knight, Edward Henry (1876), Knight's American mechanical dictionary 2, Houghton, Mifflin, p. 1057.
- Meggs, Philip B. A History of Graphic Design. John Wiley & Sons, Inc. 1998. (pp 58–69) ISBN 0-471-29198-6
- Harper, Charles A. (2000), Modern plastics handbook, McGraw-Hill Professional, p. 6.34, ISBN 978-0-07-026714-5.
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