Sand casting is a commonly employed and very ancient metal casting technique. It involves forming cavities within packed and bonded sand that is then charged with molten metal. The chosen metal solidifies to reproduce the cavity shape in fine detail. The most common technique uses a pair of boxes into which is packed the sand, to form two sides of a cavity. It is also common to cast into an open depression in sand, for a flat-backed result. It is the oldest and lowest technology casting method for producing metal components, but it retains its relevance. The technique is extensively used for one-off, small-batch, and automated large-scale production.
The origin of sand casting lies in pre-recorded history, dating back as far as the practice of metallurgy. It was the earliest and most universal technique for metal forming. Historical evidence confirms that sand casting was prevalent in Egypt (predating the first dynasty in 3,150 BC), Mesopotamia, and ancient China. The process clearly evolved independently in disparate and unconnected regions wherever metalworking and metal refining became established.
Sand casting is hugely versatile and in many regards ideal for producing an unparalleled range of metal parts. It works well in parts as small as a few grams and up to tons in weight and is suited to virtually all metals such as: gold, iron, lead, and titanium. While sand of various types is employed in the process, these materials are required to have much higher melting temperatures than the liquefaction temperatures of metals.
