Abstract: The arrangement comprises a body constructed in the form of a grip clamp arable from the vertical axis of a workpiece, and having two jaws coupled with each other in the upper portion thereof by a clamping cylinder. The arrangement further comprises cutters for deburring, and a mechanism for pressing said cutters to the workpiece surface. The cutters are mounted in the lower portion of the jaws so that cutting edges thereof form a profile of the workpiece cross-section. The cuttes disposed on the same jaw are pivotally connected with each other. The mechanism for pressing the cutters is constructed in the form of a system of hydraulic cylinders mounted on the jaws in symmetrical relationship relative to the vertical axis of the body. Said hydraulic cylinders are provided with rods operatively connected to corresponding cutters.

Abstract: Disclosed are welding current pick-ups which are switched into welding circuits. Outputs of these pick-ups are connected to inputs of a logical coincidence unit having its output connected to a control input of a welding program control unit whose output is connected with a drive adapted for moving the workpieces being welded.

Abstract: Surfaces of metal workpieces being welded are fused at a constant speed of feeding the workpieces towards each other, and the speed of feeding is, before the upsetting, increased to a final value thereof for a period of (1.0 to 4.0) (.DELTA.max/v.sub.1), where .DELTA..sub.max is the maximum gap between the workpiece surfaces being welded and v.sub.1 is the average speed of feeding the workpieces over the period of its increase. Empirical formulas are given to determine the maximum gap for workpieces of various thicknesses.

Abstract: A method consists in that the workpieces to be welded together are at first continuously moved towards each other with the welding current on and the ends of the workpieces are fused, the thermal state of the ends being monitored in terms of current, or of power, or of fusion time, or of length of the fused portion. After any of said variables has reached a preselected value which corresponds to the predetermined heating of the contact region, oscillatory movements are superimposed on the movement of one of the workpieces being welded towards the other and the fusion process is carried out till upsetting.

Abstract: In accordance with the disclosure, the workpieces being welded are brought together by rectilinearly oscillating at least one of them along the line of bringing them together with the amplitude in the movement of the workpiece towards the other workpiece greater than that in the movement of the same workpiece in the direction opposite to the direction towards the other workpiece, voltage is applied to said workpieces for flashing and heating them in the course of bringing them together, and then an upset force is applied to the workpieces. The hydraulic drive adapted to generate the oscillatory rectilinear motion in a continuous flash butt-welding machine includes a hydraulic cylinder with two chambers which provides for moving one of the workpieces being welded with respect to the other and comprises apparatus for feeding hydraulic fluid alternately into either of the chambers of the hydraulic cylinder of the machine, the apparatus being connected with the cylinder through two hydraulic lines.