Abstract: Sand cores containing an acid curable binding agent are used in the production of die castings having undercut regions because of the favorable combination of shakeout properties, resistance to washout, and resistance to surface penetration.

Abstract: This disclosure concerns a light gauge self-tapping sheet metal screw having a threaded shank and cap-type head, which head has a tool-engaging surface. Between the cupped recess of the head and the shank are a plurality of pyramidal ribs that extend partway around the shank for deforming the edge of the holes in the sheet metal up against the recessed surface of the cup of the head to increase the stripping and backout torque of the screw.

Abstract: The disclosure concerns a square die-cast elevated floor plate having a top continuous or perforated panel reinforced underneath by a polygonal tessellation grid of ribs. All of the ribs of the grid, including their integral ejector pin bosses and border flange, are of the same depth; however, concentric rows of polygons in the tessellation pattern have their ribs gradually increasing in thickness from the border flange to the center of the plate. The polygons in the pattern may comprise squares and octagons in which alternate sides of the octagons have a ratio of one to the square-root-of-two, and the sides of the squares correspond to the sides having the square-root-of-two length. The continuous or perforated top panel may be formed integrally or adhered to the tessellation rib pattern. The rib pattern with its integral ejector pin bosses is preferably symmetrical for at least 180.degree. rotation of its die.

Abstract: A resin-bonded sand core for high-pressure die casting methods having a first refractory coating, such as of silica, with an inorganic binding agent of colloidal silica and a clay such as kaolin, and a second or top coating of a refractory material containing zircon and an organic binding agent, which combination of these two different coatings enables the bonded sand core to have high pressure and temperature resistance, good washout resistance, freedom from surface penetration, and good shake-out properties.

Abstract: The disclosure concerns a formable cast aluminum alloy horseshoe having an electroless ductile metal coating having a hardness greater than that of the aluminum alloy, such as a coating of phosphorus nickel. This coating increases the wearable life of the aluminum horseshoe for quarter horse racing horses from a few days to almost a month, and its formability without cracking of the coating permits better fitting to varying sizes of hoofs.