A device for blast-machining or abrasive blasting objects such as structural elements, tools, household objects, pots, pans or the like, has a blast pot for holding a blasting abrasive which is connected via at least one line to a blasting nozzle which extends into a blasting space in which the objects which are to be blasted can be placed. The primary means arc grouped in a main housing that cannot be dismantled without damaging at least one of the components of the primary means, and the peripheral means are grouped in at least one housing capable of being connected to the main housing. Optionally, one or more extension collars may also be used. During silicon oxynitride deposition, concentration of one of the reactive gases nitrous oxide is gradually reduced so that the graded silicon oxynitride layer is oxygen-rich near bottom but nitrogen-rich near the top. In use, the device is inserted into a bait well full of eels and the nesting tube is placed flat against the bottom.