Abstract: Method of and apparatus for making metal castings using a polystyrene pattern 10 embedded in unbonded sand 20 which is consolidated to form a mould M in which is defined a mould cavity C. Molten metal is fed into the cavity C and permitted to solidify to form a casting 11. The metal is aluminum or an aluminum alloy and at least part of the mould is formed of sand which comprises at least 50% zircon sand, or other particulate material suitable for making a mould and having a bulk density lying in the range 2-3 grams/cc. The mould M may have a moulding feature 9 having upper and lower surfaces for contact with the metal and which projects inwardly of the mould cavity C from the main wall thereof and the length of any one section of the molding feature 9 being at least twice the thickness of the thinnest part thereof by which the section is connected to the main wall of the mould cavity.