Abstract: The invention relates to a process for manufacturing cold-formed, in particular cold-drawn, precision steel pipes for application in particular as pressure-operated cylinder pipes with optimum addition of one or several alloying elements as well as impurities caused by melting. A seamless, hot-formed pipe blank or welded pipe blank made from a hot strip with defined starting condition is hereby drawn in one pass or in several passes into a finished pipe, and the pipe undergoes a heat treatment before the finishing pass.

Abstract: An impact support for reinforcing a door of a motor vehicle, including a hollow profile part that is fastenable in the vehicle door. The hollow profile part having, at least in a central region thereof, a portion with a roughly oval cross section having a cross-sectional height that is greater than a cross-sectional depth. The hollow profile part is arranged in the motor vehicle door so that the depth lies parallel to an impact direction. The roughly oval cross section is formed by two straight sides which lie parallel at a distance from one another and are connected at their ends by a convex portion that has a radius that is always greater than half the distance between the two straight sides.

Abstract: A screwed pipe joint with a bell for connecting two pipes of a drill pipe string.

Abstract: A drill pipe coupling includes a coupling member (2) having an unthreaded central section (13) with a cylindrical bore (26) therein and an outer shoulder (11,12) on each side thereof. Adjoining the shoulders are respective conical external threads for threading into an internal correspondingly threaded upset head section of a drill pipe formed as a bell elements and including end surfaces (9,10). The drill pipe has an undeformed cylindrical bore (14) connected to the threaded upset head. The drill pipe end surfaces (9,10) sealingly abut the outer shoulders (11,12) of the central section (13) when the pipes are joined together. The drill pipe has an intermediate section (16) adjoining the cylindrical bore (14) and has an inside diameter which decreases in the direction toward the threaded section (5, 6).