Hi, I get parts made in China, and I need to make a full CNC drawing. It is a modified 1/4" BSP nut and orifice fitting. I cannot find anywhere how to draw the nut and orifice so they work correctly. This is the part they make the most mistakes with, as the tolerances are small. It is not practical for me to try and measure the sizes and angles of an existing one. There must be design criteria available somewhere?