Abstract: A machining center includes two independent carriages supported so that they can slide along respective longitudinal translation axes (X?, X?) by two parallel horizontal rails fixed in a raised position to a supporting structure. The carriages support respective machining heads which move along two respective translation axes (Y?, Y?, Z?, Z?). The machining heads support respective tool holding spindles arranged with a vertical axis. At least one workpiece holding table is supported at the base of the supporting structure in a rotatable manner about a first horizontal and transverse rotation axis (Yr?, Yr?) and about a second rotation axis (Hr?, Hr?) perpendicular to the first one. Two mechanized tool magazines are supported at the opposite longitudinal ends of the supporting structure and are accessible by the spindles.

Abstract: In a machining center provided with a mechanized tool magazine and with at least one movable tool-holding spindle capable of accessing the tool magazine, the tool is picked up from the tool-holding spindle and transferred to a tool replacement area by means of a dedicated, automatic transfer device that is independent of the tool magazine. After the replacement of the tool with a new tool in the transfer device, the new tool is returned to the tool-holding spindle by means of the transfer device.