Abstract: A device for forming a sprue or vent hole in a foundry sand mold. The device includes a body having a central bore and having an air outlet in the upper end of the body communicating with the bore. An axial opening in the lower end of the body has a smaller diameter than the bore. Mounted for movement within the body is a pin or plunger which has an enlarged head that is slidable within the bore and a lower stem which is slidable within the opening. The pin is urged outwardly of the body by a spring, and a seal is located between the stem portion of the pin and the wall of the body bordering the opening. The pin is formed with an internal passage, one end of which is located at the inner end of the head of the pin and the other end of the passage opens at the side of the stem.

Abstract: A method for producing large castings formed of non-machinable metals provides for inserting machinable plug members in the mold prior to casting, then pouring molten hard metal to fill the mold and surround the inserts. Removing the mold exposes the casting and portions of the inserts which may then be machined. After machining, the inserts are flame-hardened commensurate with the hardness of the casting.