Abstract: A method of applying a metallic coating to metallic sealing and/or threaded regions of steel pipes which are under high pressure per unit of surface by a pretreatment of the surface to be coated which consists of a cleaning and degreasing and an electrolytic deposition of a layer of tin by a first heat treatment at a temperature between about 150.degree. and about 200.degree. C. and a second brief heat treatment above the melting point of tin with subsequent cooling is provided. A metallic coating which is formed using said method is also provided.

Abstract: The thread of tubing to be used in the oil and gas industry and possibly additional services such as fee ing surfaces are cleaned, degreased, and pickled, nickel-coated without electric current at a layer thickness of about 1 micrometer, followed by electrolytic plating, preferably tin-plating, followed by storage at a temperature within the range from 150.degree. to about 200.degree., which is followed by brief heating for melting the tin coating, whereupon the article is quenched.

Abstract: A blend of at least 35 percent alumina and not more than 45 percent calcium oxide is blended with sand at a sand-to-cement ratio preferably 1.8 and applied to the interior of a metal pipe, for example, by means of centrifugal application and compression. Following which the resulting lining is exposed to moisture for several hours which exposure step is in turn followed by an exposure to warm steam also for several hours.

Abstract: A dispersion of a polymer such as an acrylic resin, and of a surface-acting resin, such as a melamine resin, is added to a cement mortar having a sand-to-cement ratio of 1 to 3 and a water-to-cement ratio of 0.25 to 0.35, the resin being preferably approximately 10 parts by weight per 100 parts of cement. This blend is applied to the interior of a pipe and the pipe is rotated at a speed which is gradually increased in order to produce at least approximately 20-g forces on the material for compacting same for a few minutes.