Abstract: An insert moulding system in which a movably mounted tool head loads inserts into the mould and unloads moulded articles from the mould. The tool head has sensors and an article position and retaining structure on a load face thereof for each of a number of insert pieces to be incorporated in the moulded articles. The operation is computer controlled and the sensors on the tool head sense at least one characteristic of each insert piece thereon, e.g. flatness and generate a signal in response to such characteristic being outside of specification which renders inoperative the moulding process until the offending insert piece is replaced by one meeting specification. Position locators have inter-engageable portions respectively on the tool head and the fixed in position mould positively to locate the movable head and fixed mould in a predetermined fixed relation relative to one another during cycle after cycle of operation providing precision injection moulding.