Abstract: An edge surface (18) of an article (16) is treated in a fluid (52) with a minimum effect on other adjacent side surfaces of the article by contacting the edge surface to the surface of the fluid such that the fluid wets the side surfaces and forms a meniscus adjacent to each of the side surfaces. In the meniscus the fluid stagnates and quickly becomes an inactive barrier which shields the side surfaces of the article, while the edge surface of the article remains exposed for the duration of the treatment to the active bulk of the fluid.

Abstract: A cylindrical surface of an article is electrolytically treated with a controlled, cross-sectional distribution of the electrolytic action. The distribution is achieved by placing the surface at a predetermined distance from a formed electrode to control the influence of the electrode on each portion of the surface along a cross section thereof. The influence on each such portion with respect to other portions of the surface is determined by the magnitude of an influence number associated with such portion in relation to the magnitude of similar influence numbers associated with the other surface portions along the cross section.