An orifice holder assembly comprising: a cast orifice holder of unitary construction having a base connected to a boss, said boss having a bore therethrough extending from a first boss surface to a second boss surface with said second boss surface located above the first boss surface, said base having an outlet extending thereacross above the boss and at least one shoulder for connecting the orifice holder to a cooktop; a tube received by the boss, said tube having a preformed bead disposed about the tube and spaced from a tube end, said bead contacting the first boss surface with a portion of the tube extending through the bore of the boss, said tube then deformed at the tube end to provide a lip with a lip engagement surface in contact with the second boss surface external to the bore with the lip and the bead forming a mechanical connection of the tube to the boss by entrapping a portion of the boss between the lip and bead; and an orifice body connected to the tube end and having a bore therethrough, said orifice body located below the base with a cavity above the orifice body and below the base and said orifice body terminating internal to the boss above the first boss surface; and characterised in that the base is integrally connected to the boss by a cup, with the boss located on a bottom portion of the cup, and wherein the base and the boss are longitudinally separate and the cup extends from an internal perimeter of the base to an external perimeter of the boss to form a sealed connection that ensures at least greater than 50 percent of air mixed with fuel from the orifice body is received from above the cooktop when the orifice holder assembly is connected to a cooktop. a cast orifice holder of unitary construction having a base connected to a boss, said boss having a bore therethrough extending from a first boss surface to a second boss surface with said second boss surface located above the first boss surface, said base having an outlet extending thereacross above the boss and at least one shoulder for connecting the orifice holder to a cooktop; a tube received by the boss, said tube having a preformed bead disposed about the tube and spaced from a tube end, said bead contacting the first boss surface with a portion of the tube extending through the bore of the boss, said tube then deformed at the tube end to provide a lip with a lip engagement surface in contact with the second boss surface external to the bore with the lip and the bead forming a mechanical connection of the tube to the boss by entrapping a portion of the boss between the lip and bead; and an orifice body connected to the tube end and having a bore therethrough, said orifice body located below the base with a cavity above the orifice body and below the base and said orifice body terminating internal to the boss above the first boss surface; and characterised in that the base is integrally connected to the boss by a cup, with the boss located on a bottom portion of the cup, and wherein the base and the boss are longitudinally separate and the cup extends from an internal perimeter of the base to an external perimeter of the boss to form a sealed connection that ensures at least greater than 50 percent of air mixed with fuel from the orifice body is received from above the cooktop when the orifice holder assembly is connected to a cooktop.