Abstract: A thin sheet metal orifice plate is disclosed having at least one orifice therethrough with a rounded inlet to improve flow and an outlet defined by an encircling projection whose axis accurately conforms to a predetermined direction. Apparatus for the production of such an orifice plate is disclosed and includes a forming tool operable to form a spherical boss in a flat intermittently advanced thin metal sheet of orifice blank material. The apparatus includes an orifice plate blank trimming tool having a punch and die assembly for accurately trimming the spherical boss from a continuous strip such that an annular flange is provided therearound. An orifice punching apparatus is provided having a chuck for holding an orifice plate blank adjacent to a resilient backing material. The chuck is supported by an angular adjustment apparatus which, in turn, is rotatably supported on a base and provided with a pair of detent mechanisms. The detent mechanisms secure the angular position of the adjustment apparatus.