A double-tube core drill wherein the inner tube (2) is connected to the outer tube (1) by a multi-element needle and/or ball bearing (11), allows for the inner tube (2) to be made rigid and prevents it from rotating along with the outer tube (1). The extraction device (9) and the inner wall (38) of the tube are preferably covered with an antifriction coating. A set of stabilizing elements (67) are spread along the outer tube to stabilize the inner tube (2). Said inner tube has a tapered shoe (32) provided with a lower bevelled lip (14). The drill also comprises a device for indicating that the core has jammed in the inner tube (2) and a sealing device (19) designed to receive a ball (46) provided for sealing the inner tube (2) of said core drill.
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