Abstract: A dust exhausting hood is for use with surface working machines such as surface grinders. To enable the hood to remain in close contact with the surface being worked, a mantle which surrounds the working tool is connected to a mounting ring, engaged on the machine head, by guide means which permit both axial movement and tilting of the mantle of the hood with respect to its mounting ring, the mantle being constantly urged into contact with the worked surface by means of a compression spring acting between the mounting ring and the mantle. To permit maximum axial movement of the mantle, within limits, with respect to the mounting ring, the spring is a helical spiral spring which can be compressed into planar form.