A broach (1) that is mountable on a tool-holding turret of a numerically controlled lathe for carrying out chip removal machinings on a workpiece (P), comprises: a supporting body (2) that is fixable to the tool-holding turret; at least a first tool-holding shaft (8) and a second tool-holding shaft (9) that are rotatably supported by the supporting body (2) for supporting respectively a first broaching tool (10) and a second broaching tool (11); and driving means that is rotatably supported by the supporting body (2) and removably connectable to a drive of the tool-holding turret for rotating the first tool-holding shaft (8) and the second tool-holding shaft (9) at an adjustable rotation speed (α).