Abstract: A down hole rock drill bit and method of manufacture of the same comprising a cast metal drill bit body having a plurality of hardened carbide studs partially cast in the drill bit body. The drill bit is cast by means of a foam pattern replicating the drill bit, typically made from polystyrene within which a plurality of carbide studs are partially inserted into the grinding surface of the foam drill bit model. The model is then subsequently supported within a vessel of sand and molten metal is poured over the foam, vaporizing it and taking the exact form of the foam pattern and permanently retaining the carbide studs within the metal drill bit.

Abstract: A down hole rock drill bit and method of manufacture of the same comprising a cast metal drill bit body having a plurality of hardened carbide studs partially cast in the drill bit body. The drill bit is cast by means of a foam pattern replicating the drill bit, typically made from polystyrene within which a plurality of carbide studs are partially inserted into the grinding surface of the foam drill bit model. The model is then subsequently supported within a vessel of sand and molten metal is poured over the foam, vaporizing it and taking the exact form of the foam pattern and permanently retaining the carbide studs within the metal drill bit.

Abstract: A method of manufacturing a plate-type track shoe. The method involves casting or obtaining a cast, plate-type track shoe which has been made from a suitably high quality ductile iron and heating the plate-type track shoe to a desired austentizing temperature within a range of about 1450.degree. F.-1750.degree. F. for up to about six hours to austentize the ductile iron. The plate-type track shoe is then rapidly cooled to a desired austempering temperature within a range of about 450.degree. F.-800.degree. F. and maintained at the desired austempering temperature for up to about 6 hours to isothermally produce a plate-type track shoe having an ausferrite microstructure. The plate-type track shoe is then cooled, washed, and optionally coated with a rust inhibitor and/or coated or painted. The process produces austempered plate-type track shoes which have high strength, excellent durability, and which are less costly to produce, per pound, than comparable parts manufactured from formed steel.