Abstract: The invention relates to a machine for edge-milling (rumbling) concrete blocks (1) which have not yet hardened, having a horizontal conveyor (3) for transporting the concrete blocks (1) lying in one position on a support plate (2), and a hammer mechanism (4), arranged over the horizontal conveyor (3). The hammers (8) of this hammer mechanism (4) are arranged behind one another in several rows in the direction of transport and over a gap, so that they can hammer on the upper sides of the concrete blocks (1) laid under them. The individual hammers (8) are suspended on lifting drives (13-18).