[en] A pair of 80 kV, 12 kW electron beam welding machine was manufactured with in-house technology. One of the above machines has been installed and commissioned at BARC Incubation Centre at Trombay. Welding of various materials such as copper, Zircaloy-2, Zr-Nb alloy, aluminum alloy, tantalum, Ta-W alloy, Cu-Be alloy were carried out during the commissioning of the machine. Welding of a number of components for specific applications have been welded successfully immediately after the commissioning. Drift tube, Ceramic-metal multi stud feed through, precision censor, Tantalum hood and Caned motors are few among them. Correct fixturing of the jobs were planned and fabricated before each welding. Weld parameters were optimized for each of the components to provide desired penetrations and weld quality. Authors shall discuss in detail about the welding tool, the testing of the welded specimen and metallographic studies of some of the test specimens. General and specific testing of the welded components carried out along with their results will also be tabulated in the paper. (author)