Abstract: An improved pressure sensor assembly includes a low-cost pressure port comprising a casing formed of cold rolled steel, a small stainless steel insert and an O-ring. The casing has a threaded slug at one end for attaching the sensor assembly to the wall of a pressure vessel and an annular cup at the other end. The annular cup has a hex-shaped periphery to facilitate installation and removal of the sensor assembly, and defines a cylindrical interior cavity including an annular recess in which the O-ring is disposed. The stainless steel insert has a base portion disposed within the cylindrical cavity atop the annular recess so as to compress the O-ring between the insert and casing, and a neck portion that extends out of the cavity to form a pedestal to which the stainless steel pressure sensor element is welded. The insert is retained relative to the casing by a staking operation in which a portion of the casing is deformed against the neck of the insert.