Abstract: A spruing assembly for receiving investment material in the production of an investment mold for castings by the "lost wax" process which includes a hollow chamber to receive the investment material. Included within the chamber is one or more sprue for supporting the wax pattern(s) to be cast and one or more corresponding predetermined shaped reservoir(s) being slidably moveable up or down the sprue to create the heat center of the investment mold. Where a long span casting is to be produced all the reservoirs are connected to form a continuous reservoir or Feeder Bar which conforms to the curve of a long span dental arch. A base member is provided within the chamber for supporting the sprue.

Abstract: An improved sprue pin for producing castings by the lost wax method wherein the sprue pin gradually decreases in external circumference toward the tip of the sprue. The length and gauge of the sprue is such that it provides acceptable flow rates and solidification times for new base metal and palladium alloys. A set of lines about the circumferentially decreasing tip allows the user to conform the sprue to the size of the wax pattern being used to form the casting.

Abstract: A spruing assembly for receiving investment material in the production of an investment mold for castings by the "lost wax" process which includes a hollow chamber to receive the investment material formed by a base member and an engaging tapered ring. A horizontal feeder bar is contained within the chamber and is supported by hollow sprue means. The feeder bar is open at its top and has a narrow channel for conducting molten wax into the hollow sprue support. The base member includes a centralized sprue base former and support means associated with the former to provide support for the hollow sprue means supporting the feeder bar.