Abstract: An industrial process is disclosed for cleaning undesirable, dirty residue from the surfaces of metal articles. The process comprises mixing an alkaline cleaner and an emulsion cleaner, and intimately contacting the metal articles with the cleaning mixture at ambient temperatures.

Abstract: A flaw penetrant test panel having a sheet metal surface in which are impressed tiny or microscopic flaw simulating cavities distributed over the test surface to receive one or more penetrants being tested, the mouth size of the cavities being in the range of about 1 to 10 thousandth inch and being formed by heating the metal to incipient softening temperature followed by penetration of the surface test area using a needle-like tool proportioned to the desired cavity size and depth and which upon penetration of the metal displaces it in a crater-like rim about the cavity being formed.