A device for cutting at least one end of a core (Ca) of relatively hard material in the form of a circular cylinder about a first axis of revolution (Ar) and of radius R, in order to make plane end faces, the device comprising a base, a saw blade, means for driving said saw blade in cutting motion in a cutting plane, means for moving said saw blade relative to said base in translation in the cutting plane, at least one cradle in the form of at least a first portion of a circular cylinder about a second axis of revolution and of radius R, at least a first end of said cradle being open, said cradle also having a side opening defined in a plane parallel to said second axis of revolution and situated between said second axis of revolution and said first cylinder portion, means for securing said cradle with said base in such a manner that said first end of said cradle is situated in the proximity of the cutting plane and the second axis of revolution forms a non-zero angle with the cutting plane, at least one bearing part, means for moving said bearing part between two positions, namely a first position in which the bearing part is entirely contained in the half-space defined by a plane parallel to the cutting plane and passing via the first end of the cradle and containing said cradle, and in which the minimum distance between the bearing part and the second axis of revolution is substantially equal to the value R, and a second position in which the bearing part is contained entirely in said half-space, and in which the minimum distance between the bearing part and the second axis of revolution is greater than the value R, said at least one bearing part being in the form of at least one second circular cylinder portion about a third axis of revolution and of radius R, at least a first end of said bearing part being open, said bearing part also including a side opening defined in a plane parallel to said third axis of revolution and situated between said third axis of revolution and said second cylinder portion, the means for moving said bearing part between the two said positions (P1, P2) being arranged so that in the first position the second and third axes of revolution (22, 32) coincide, the planes of the side openings (24, 34) respectively of the first and second cylinder portions (21, 31) being substantially parallel, and the first end of said bearing part faces towards said cutting plane, and that in the second position said second and third axes of revolution (22, 32) do not coincide, said bearing part remaining in said half-space, the device being characterized by the fact that the means for moving said bearing part between the first and second positions (P1, P2) comprise: • means for mounting said bearing part to pivot relative to said base about a first pivot axis perpendicular to the second and third axes of revolution (22, 32); and • means for controlling pivoting of said bearing part about said first pivot axis between the first and second positions (P1, P2). • means for mounting said bearing part to pivot relative to said base about a first pivot axis perpendicular to the second and third axes of revolution (22, 32); and • means for controlling pivoting of said bearing part about said first pivot axis between the first and second positions (P1, P2).