You're here via the Patternmaking page so you obviously want to know a little more about Pattern Equipment and Castings.
Okay, for some reason you require a casting. It could be for anything - car, motorcycle, locomotive, something for the bathroom. You know you need a casting because everyone says so, but you're not sure how to go about obtaining one! If the casting is available commercially, all well and good. Go out and buy it. Trouble comes when the casting you need is either no longer available or it's something you've designed but don't know how to get made.
Castings are produced in foundries. Foundries tend to concentrate on particular families of metals: Aluminium Alloys, Brass and Bronzes etc. Even in these high tech days the majority of castings are produced in sand moulds, not the sand used by your local builder but modern moulding sand containing resin ingredients which give it special characteristics, not least of which is strength.
Right, we now have our idea, we have our foundry, and it has its sand. Next we need a sand mould with a cavity the shape and size of the part we need. To produce this cavity we require pattern equipment for the foundry to produce the mould. In its simplest form, a pattern is an exact replica of the casting required: it will be slightly larger than the finished casting to allow for the contraction of molten metal as it cools in the mould after pouring and every metal has it's own contraction allowance. Of course life is never simple and the casting may need to be hollow or incorporate some feature which precludes the use of a direct replica. It is beyond the scope of this web site to act as an instruction course on patternmaking (hey! I did a seven year apprentiship), but if you imagine the complex nature of say, an automobile engine cylinder head, you can see why a patternmaker has to be able to read engineering drawings and think in three dimensions, inside out! He then has to produce the equipment required by the foundry for them to make, in essence, in sand, a 3-D jigsaw with a cavity in it. Not exactly a piece of cake (or a gritty biscuit...).
It is a highly skilled craft; an old one too. Ever since ancient man discoverd how to extract metals from ore there have been (if not in name) patternmakers. In all probability, the earliest moulds would have been hollows in the ground into which molten metal would have been poured. Later, for more accurate work, clay moulds were used. Which doesn't really concern us, neither would it have mattered to our ancestors; they hadn't the words 'patternmaker' and 'foundrymen'.....or maybe they did.
The real and dynamic world explosion in both patternmaking and foundry work came with the start of the Industrial Revolution, and was centred not 25 miles from here, at the Shropshire town of Ironbridge, so named after the cast iron bridge which spans its gorge. The development of iron workings was to change the world and from it the way we live our lives. From that time onwards, castings, with the help of patternmakers, have entered every area of our lives, from transport to architecture, civil engineering to domestic appliances, dentistry to rocket science.