the entrances of all channels 40 are counterbored shown in fig3 to prepare the entrance for the socket weld 46 the penetrator 20 is then drilled with side channels to intersect the straight section of channels 40b and 40c the diameters of the side channels are selected to match the diameters of the straight section of channels 40b and 40c that they will be intersecting the centers of the side sections of channels 40b are located such that the side section will intersect the straight section of channels 40b a ball end mill may be used to form a smooth 90 u00b0 transition within the penetrator side channel sections are similarly drilled and milled to intersect the straight sections of channels 40c next in the penetrator 20 manufacturing process a number of plugs 48 fig2 are made from the same material as penetrator 20 with a length equal to the distance between the end face of penetrator 20 and the center of radial holes 40b less a distance dictated by consideration of strength of the weld which will hold it in place the length of plugs 48 for channels 40c if used will of course be appropriately longer the plugs 48 are machined to an interference.