with reference to fig1 , 2 and 3 , a first form of embodiment of a machine 10 used for the bending of tubular elements , or tubes 11 is shown . both for this form of embodiment described and for the forms of embodiment described hereafter , the relative representations are deliberately schematic , in order to better understand the characteristics of the machine according to the present invention . operating details such as , for example , the diameters of the tubes , the radiuses of curvature achieved , the sizes of the core and others , have been deliberately chosen randomly so as not to constrain the individual forms of embodiment to specific operating solutions , also considering the fact that one of the main advantages of the present invention is the excellent operating applicability of the bending machine substantially for any type of tube with any radius of curvature . in this case , the machine 10 comprises a bending member 12 and a movement member 13 , in this case represented by an unwinding reel 23 . the movement of the tube 11 , in a manner known in the state of the art , is achieved by means of a motorized roller - way or with other systems of an alternative type , such as a gripper , or similar means , not shown here in detail , which carry out both the first feed of the tubes 11 toward the bending member 12 and the advance of the tubes 11 during the work steps . in the following description , the reference numbers 13 , 113 , 213 are used to indicate in general the member which moves the tube 11 linearly in the direction of feed which , being known , is not shown in detail in the drawings . the machine 10 according to the present invention also comprises a holding member 15 , the function of which will be described in detail hereafter . the bending member 12 comprises a bend core 16 and a bending arm 17 , which is mobile with respect to the bend core 16 in order to bend the tubes 11 fed . in particular the bend core 16 is disposed inside the tubes 11 so as to function as contrast , inside the tube 11 , to the bending action exerted externally by the bending arm 17 . the bend core 16 comprises , in its turn , a polarized support bar 19 , a contrasting ogive 20 and , in the case shown in the drawings , at least a bend - follower element 21 disposed articulated at the head of the contrasting ogive 20 . there may be only one bend - follower element 21 , as in the drawings , or of the multiple type , or it may not be there at all , if the type of bending and / or machine does not require it . the bending arm 17 is of the substantially known type and is only shown schematized in the drawings . the bending arm 17 acts externally to the tube 11 to be bent in order to confer on the latter , in coordination with the advance imparted by the movement member 13 , the bending radius envisaged . the bending aim 17 can be selectively positioned on different planes transverse to the direction f , in order to bend the tubes 11 on different planes . the machine 10 also comprises a cutting tool 22 , for example a milling cutter or other , in this case , disposed downstream of the holding member 15 and upstream of the bending member 12 , which allows to cut to size one segment of tube 11 , at the end of the bending steps . within the framework of the present invention , here and in the variant solutions shown hereafter , it is understood that the cutting tool 22 could also be disposed downstream of the bending member 12 , or there could be one or more cutting members 22 upstream and one or more cutting tools downstream of the bending member 12 . the tube 11 is fed in the same direction of feed “ f ”, and in the same sense , both in the feed step of the tube 11 to the bending member 12 , and also during the bending steps . the direction and sense of feed define a head - wise feed and a head - wise working of the tube 11 . the holding member 15 comprises at least a magnetic element 25 ; by this term we mean permanent magnets , electro - magnets or other similar or comparable element . the magnetic element or elements 25 are disposed annularly around a zone in which the tube 11 is fed , in proximity to the bending member 12 , defining an interspace between it and the bend core 16 in which the tube 11 can be inserted . the permanent magnets 25 thus disposed define , with their magnetic fields , a median zone , axial to the direction of feed “ f ”, of magnetic balance . the bend core 16 is disposed with its support bar 19 in this median zone of magnetic balance . the support bar 19 , being polarized , remains substantially suspended in correspondence to this zone , also absorbing , among other things , the axial forces which they generate during bending . therefore , the whole bend core 16 is maintained suspended by the action of the magnetic fields generated by the permanent magnet or magnets 25 , so as to allow the feed in the direction “ f ” required , without risk of interference with possible structures for the support of the bend core 16 in its operating position . as shown in sequence in fig1 , 2 and 3 , in this form of embodiment of the machine 10 , the tube 11 is fed from a roll by the action of the unwinding reel 23 in the direction of feed “ f ”, and directed head - wise toward the bending member 12 . before reaching the bending arm 17 , the leading end of the tube 11 is made to pass inside the holding member in the interspace defined between the permanent magnet or magnets 25 and the bend core 16 , so that the latter is disposed in suspension inside the tube 11 . in the form of embodiment shown in fig4 , 5 and 6 , a second form of embodiment of the machine 110 according to the present invention is shown schematically . in this case the machine 110 comprises a bending member 12 , a movement member 113 , and a holding member 115 , the latter two being of a different conformation than has so far been described . the bending member 12 is the same as that described for the solution in fig1 , 2 and 3 , and comprises the bend core 16 and the bending arm 17 , for bending the tubes 11 fed . the movement member 113 , in this case , comprises a motorized unwinding reel 23 able to unwind from a roll the tube 11 to be bent , and a movement pincers 123 disposed downstream of the unwinding reel 23 and upstream of the bending member 12 , with respect to the direction of feed “ f ”. in this case too there can be other feed members present , but not shown here , such as a roller - way , etc . in this variant solution too , the tube 11 is fed head - wise in the same direction of feed “ f ”, and in the same sense , both by means of the unwinding reel 23 and also by means of the movement pincers 123 . the holding member 115 comprises a first gripping pincers 26 and a second gripping pincers 27 disposed in cooperation with the bend core 16 , in order to keep it in a suspended condition , acting on one side of the tube 11 . in particular the first gripping pincers 26 is suitable to cooperate with a tail end of the support bar 19 of the bend core 16 ; while the second gripping pincers 27 is suitable to cooperate with the contrasting ogive 20 of the bend core 16 . the operating sequence of the two gripping pincers 26 and 27 will be described in detail hereafter . the machine 110 in this case also comprises a cutting tool 122 , for example a milling cutter or other , in this case disposed upstream of the first gripping pincers 26 , and able to cut to size a segment of tube 11 before bending . as shown in sequence in fig4 , 5 and 6 , in this form of embodiment of the machine 110 , the tube 11 is initially unwound from a roll by the action of the unwinding reel 23 , and moved in the direction of feed “ f ” by the feed member 113 , and directed head - wise toward the bending member 12 . during the feed of the tube 11 , the bend core 16 is kept in a suspended condition by the action of the second gripping pincers 27 . before reaching the second gripping pincers with the leading end of the tube 11 , the unwinding reel 23 stops the feed of the tube 11 and the cutting tool 122 cuts to size the segment of tube 11 to be bent . before the definitive cut of the segment of tube 11 , the segment is associated to the movement pincers 123 . in a variant of this solution two cutting units can be provided , in which a first cuts one segment made from multiples of the product , and a second is positioned after the bending member 12 and cuts to size the bent tube . once the cutting to size has been carried out , the unwinding reel 23 partly recovers the tube 11 , separating from the cut segment , and freeing a back section of the support bar 19 of the bend core 16 . in this condition , the first gripping pincers 26 is brought into cooperation with this back section of the support bar 19 , and subsequently the second gripping pincers 27 is discharged , releasing the contrasting ogive 20 . at this point the movement pincers 123 feed the segment head - wise in the direction f in the same sense of feed executed with the unwinding reel 23 , so as to bring it into cooperation with the bending member 12 and perform the required bends . in the form of embodiment shown in fig7 , 8 and 9 , the bending machine according to the present invention is shown in its entirety with the reference number 210 . in this case the machine 210 comprises a bending member 12 , a movement member 213 , and a holding member 215 , the latter two having a conformation different from both the solutions so far described . the bending member 12 is the same as that described for the previous solutions and comprises the bend core 16 and the bending arm 17 . in this case the tube , rather than being fed from a roll , is fed in bars 211 of a length substantially multiple to the length of the individual segments to be bent . in this case , the movement member 213 comprises movement pincers 223 disposed in cooperation with a back end of the bar 211 , in order to determine a movement thereof toward the bending member 12 in the direction of feed f . the holding member 215 comprises a support bar 219 directly connected to the back part of the contrasting ogive 20 of the bend core 16 . the support bar 219 is made of flexible material , with articulated meshes or other , so as to be able to feed the contrasting ogive 20 from the back surface of the tubular bar 211 , with a curvilinear path , and in any case guarantee sufficient rigidity in the operating position of the contrasting ogive 20 . the machine 210 in this case also comprises a cutting tool 222 , for example a milling cutter or other , in this case disposed upstream of the bending arm 17 , and able to cut to size a segment of tube 11 after bending . as shown in sequence in fig7 , 8 and 9 , in this form of embodiment of the machine 210 , the tubular bar 211 is initially fed from a store and disposed in the direction of feed f . from here the movement pincers 223 feed the bar 211 head - wise toward the bending member 12 . once the bar 211 is disposed in cooperation with the bending member 12 , the bend core 16 is inserted axially to the bar 211 from a back end of the latter , until it reaches the position of cooperation , inside the bar 211 , with the bending arm 17 . the bar 211 is then progressively fed by the movement pincers 233 to carry out the desired bends . at the end of bending , the cutting tool 222 cuts the segment to size , in order to resume the bending cycle of a new section of the bar 211 , always fed head - wise . it is clear that modifications and / or additions of parts or steps may be made to the machine 10 and the cutting method as described heretofore , without departing from the field and scope of the present invention . for example , it comes within the scope of the present invention to provide that cutting tools 22 , 122 , 222 are disposed downstream of the bending member 12 , or in another position with respect to the bending member 12 , depending on the different operating conditions . according to another variant , the support bar 19 is polarized by means of a magnetic core , or an electric current or other known polarization system , able to generate a magnetic field contrasting the action of the field generated by the permanent magnets 25 , or by the electro - magnets . it is also clear that , although the present invention has been described with reference to some specific examples , a person of skill in the art shall certainly be able to achieve many other equivalent forms of machine for bending tubular products and relative cutting method , having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby .