METHOD FOR PRODUCING A SCREW ELEMENT BLANK AND A SCREW ELEMENT, AND SCREW ELEMENT BLANK AND SCREW ELEMENT

Abstract

The invention relates to a method for producing a gland or a gland blank (3), the method comprising a step of producing a blank (3) having a cylindrical shaft (5) formed on a screw head (4), and a blind hole (7) being formed in the blank (3) from an upper side (11) of the screw head (4) facing away from the shaft (5) in a, in particular further, method step, the blind hole (7) extending toward the shaft (5) and forming at least one first section (13), in particular having a polygonal cross section (Q1), preferably for receiving a screw tool. The blind hole (7) is deepened, thus forming at least one second section (14), which borders the first section (13), in a subsequent method step, the second section (14) forming a preferably at least partially continuous cross section (Q2) which is in particular smaller in size than the first cross section (Q1), the shaft (5) being widened in sections, thus forming an undercut (15) at the crossover between the shaft (5) and the screw head (4), in particular by at least indirectly displacing material from at least the second section (14) of the blind hole (7), in the subsequent method step.

Claims

1. A method for producing a screw element or a screw element blank (3), the method comprising a step of producing a blank (3) having a cylindrical shaft (5) formed on a head (4), and a blind hole (7) being formed in the blank (3) from an upper side (11) of the head (4) facing away from the shaft (5), the blind hole (7) extending toward the shaft (5) and forming at least one first section (13), wherein the blind hole (7) is deepened, thus forming at least one second section (14), which borders the first section (13), in a subsequent method step, the second section (14) forming an at least partially continuous cross section (Q2) which is smaller in size than the first cross section (Q1), the shaft (5) being widened in sections, thus forming an undercut (15) at the crossover between the shaft (5) and the head (4) by at least indirectly displacing material from at least the second section (14) of the blind hole (7), in the subsequent method step.

2. The method according to claim 1, wherein the shaft (5) is widened at least in an area (16) opposite the head (4).

3. The method according to claim 1, wherein a part of the widened section (16) abuts against a radial deforming tool or tool part (2.4) after the subsequent method step has been executed, whereas the part of the shaft (5) forming the undercut (15) forms a distance axially increasing toward the head (4) with respect to the radial deforming tool or tool part.

4. The method according to claim 1, wherein a flat end face of the shaft (5) facing away from the head (4) or an end face of the shaft (5) which is equipped with a protrusion axially extending away from the end face remains or is formed in the scope of the subsequent method step.

5. The method according to claim 1, wherein an annular sealing surface (20) is formed on an underside (9) of the head (4) facing the shaft (5) for being abutted against an abutment surface of a receiving body, thus forming a coaxial annular groove, which is bordered radially outward by an encircling annular wall.

6. The method according to claim 1, wherein a washer is disposed in the area of the undercut (15), the washer being deformed such that the inner diameter is slightly larger than the outer diameter of the undercut and is smaller than the outer diameter of the widened section (16) of the shaft (5) after having been deformed.

7. The method according to claim 1, wherein a maximum widening of 2% to 9% with respect to the shaft diameter is produced in the subsequent method step.

8. The method according to claim 1, wherein the blind hole (7) is realized in such a manner that a bottom (18) of the second section (14) of the, blind hole (7) extends up to 80% of the overall height of the screw element starting from the upper side (11) of the head (4) after the subsequent method step has been executed.

9. The method according to claim 1, wherein the first section (13) of the blind hole (7) is realized in such a manner that a bottom of the first section (13) of the blind hole (7) extends up to 70%, of the overall height of the screw element starting from the upper side (11) of the head (4).

10. The method according to claim 1, wherein the first section of the blind hole is formed in two or more partial steps, 700 of the overall depth of the blind hole being produced in a first partial step.

11. The method according to claim 1, wherein the second section (14) of the blind hole is produced in such a manner in the scope of the subsequent method step that a bottom (18) of the, second section (14) of the blind hole (7) is formed in the axial direction (A) in an area (16) of maximum radial widening.

12. The method according to claim 1, wherein a bottom (18) of the second section (14) of the blind hole (7) is formed in the axial direction (A) in the head (4).

13. The method according to claim 1, wherein the shaft (5) is equipped with a thread in particular by means of non-machining methods, the thread being realized in such a manner relative to the widened portion and to the undercut (15) that the thread completely tapers off in the area of the undercut (15).

14. The method according to claim 1, wherein the material between the bottom of the second section (14) and an end face of the shaft (5) facing away from the head (4) is punched or stamped while maintaining the undercut, in a step for producing a hole.

15. The method according to claim 14, wherein an internal thread, which extends from the head (4) to an end face of the shaft (5) facing away from the head (4), is produced by machining in the hole produced in the step for producing the hole.

16. The method according to claim 1, wherein an outer tool engagement portion is formed in a method step after having formed the first section of the blind hole in the area of the head (4), the outer tool engagement portion extending across the entire height of the head (4) at least after a subsequent deburring process.

17. A screw element blank produced according to claim 1 a method according to, the screw element blank comprising a head (4) and a cylindrical shaft (5) formed on the head (4), a blind hole (7) extending toward the shaft (5) starting from the head (4) and having at least one first section (13) having a polygonal cross section (Q1) for receiving a screw tool or having a round cross section (Q2) as a precursor of a screw opening (23), and the shaft (5) comprising an undercut (15) at the crossover to the head (4), wherein the blind hole (7) comprises a second section (14) bordering on the first section (13), the second section (14) having an at least partially continuous cross section (Q2) which is smaller in size than the first cross section (Q1), the undercut (15) being formed by a widened portion formed on part of the shaft (5) by at least indirectly displacing material from at least the second section (14) of the blind hole (7) at the crossover between the shaft (5) and the screw head (4).

18. The screw element blank according to claim 17, wherein the shaft (5) has the widened portion at least in an area (16) opposite the screw head (4).

19. The screw element blank according to claim 17, further comprising a flat end face of the shaft (5) facing away from the head (4) or an end face of the shaft (5) which is equipped with a protrusion axially extending away from the end face.

20. The screw element blank according to claim 17, further comprising an annular sealing surface (10), which is formed on an underside (9) of the head (4) facing the shaft (5), for being abutted against an abutment surface of a receiving body, thus forming a coaxial annular groove, which is bordered radially outward by an encircling annular wall.

21. The screw element blank according to claim 17, wherein a maximum widening is 2% to 90% with respect to the shaft diameter at the crossover to the head (4).

22. The screw element blank according to claim 17, wherein a bottom (18) of the second section (14) of the blind hole (7) extends up to 80% of the overall height of the screw starting from the upper side (11) of the head (4).

23. The screw element blank according to claim 17, wherein a bottom (18) of the second section (14) of the blind hole (7) extends in the axial direction (A) in an area of maximum radial widening.

24. The screw element blank according to claim 17, wherein the blind hole (7) comprises a third section (17), which borders the second section (14), the third section (17) being concentric to the first and/or second section (13, 14) and forming a cone segment, which tapers in the direction (A) of the shaft (5) and ends in in a flat bottom (18) of the blind hole (7) extending parallel to the upper side (11).

25. A screw element, comprising a gland produced from a screw element blank according to claim 17.

26. The screw element according to claim 25, wherein the shaft (5) has a thread realized in such a manner relative to the widened portion and to the undercut (15) that the thread completely tapers off in the area of the undercut (15).

27. A screw element, comprising a nut produced from a screw element blank according to claim 17.

28. The screw element according to claim 27, further comprising a screw opening, which is formed in the shaft by a recess widening the blind hole to an axially continuous opening.

29. The screw element according to claim 27, wherein the screw opening comprises an inner thread, which extends across the entire screw opening.

30. The screw element according to claim 27, further comprising a washer, which is captively disposed in the area of the shaft, for which purpose the inner diameter of the washer is smaller at least in sections than the outer diameter of the widened area (16) of the shaft (5) and is slightly larger than the outer diameter of the undercut (15).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Further advantages, features and details of the invention can be derived from the following description of preferred exemplary embodiments and from the drawings.

[0056] FIGS. 1a, 1b show a first method step preceding the method of the invention for producing a screw element blank and a blank emerging from the method step;

[0057] FIGS. 2a, 2b show a first method step for producing a screw element according to the invention or a screw element blank according to the invention and a corresponding screw element blank;

[0058] FIGS. 3a-3c show a subsequent method step for producing a screw element according to the invention or a screw element blank according to the invention and a corresponding screw element blank;

[0059] FIG. 4 shows a perspective view and a perspective cut view of a stage process which aims at producing a screw element blank according to the invention and comprises the method according to the invention;

[0060] FIG. 5 shows a stage process which aims at producing a screw element blank according to the invention and comprises the method according to the invention in a lateral cut view and in a partial top view on the corresponding stages of the blanks;

[0061] FIG. 6 shows a schematic view of a washer for use with a screw element according to the invention or a screw element blank according to the invention.

DETAILED DESCRIPTION

[0062] In FIGS. 1 to 3, an exemplary embodiment of the invention is described, which refers to a screw element designed as a gland and the corresponding production. Individual features, method steps or properties can, however, also be used for the following description of a screw element or a blank for a screw nut.

[0063] FIG. 1a shows a two-piece tool 1 and a blank 3 of a gland located in tool 1, in particular between the two tool pieces 2. FIG. 1b shows blank 3 of a gland as obtained by carrying out the method step which is produced within the scope of processing using tool 1 of the method step of FIG. 1a. The processing according to FIG. 1a and the shape of blank 3 according to FIG. 1b precede the method according to the invention or can precede the method according to the invention. In particular, however, the shape of blank 3 and the embodiment of tool parts 2 of tool 1 display the hitherto known limitations or boundaries of cold extrusion. The two tool parts 2 form a receiving tool part 2.1 and a deforming tool part 2.2 on the one hand, receiving tool part 2.1 having a constriction or tapering extending away from screw head 4 in axial direction A. This ensures that shaft 5, which borders head 4, can be removed or exited from receiving tool part 2.1 in particular via a pushing or thrusting movement using a plunger 2.3 in axial direction A after the processing step or the method step as illustrated in FIG. 1a has been executed.

[0064] In the method step or in the production stage of the gland or of gland blank 3, as illustrated in FIG. 1a, it is accordingly of no consequence that shaft 5 of blank 3 completely abuts against the radial walls of receiving tool part 2.1 after deforming tool part 2.2 has been applied. However, as in particular FIG. 1a illustrates, a flank or tapering of shaft 5 oriented differently or negatively in axial direction A with respect to the longitudinal axis, i.e., a tapering toward screw head 4, would not be possible at least for a one-piece receiving tool part 2.1, since an exit or ejection via plunger 2.3 would fail because the end side or end face 6 of blank 3 has a larger diameter with respect to the crossover between shaft 5 and head 4 of blank 3, thus making an ejection in axial direction A impossible at least without reversing the tapering.

[0065] Besides head 4 and shaft 5 bordering head 4, which is still tapered in the example of FIG. 1b from the crossover between head 4 and shaft 5 to the end side or end face 6 of shaft 5 in the axial direction, corresponding blank 3, as illustrated in FIG. 1b, consequently also comprises a blind hole 7 or a preliminary form of a blind hole 7. Blind hole 7 is deformed in blank 3 or impressed in blank 3 by a stamp 8 comprised by deforming tool part 2.2, the preliminary form of blind hole 7 leading to shaft 5 being circumferentially or radially pressed against and thereby molded to tool 1, in particular receiving tool 2.2, material being displaced in the process.

[0066] In addition, the abutments in the area of head or screw head 4 are already present in blank 3 of FIG. 1b in order to form an annular sealing surface 10 on an underside 9 of head or screw head 4 facing shaft 5 for abutting against an abutment surface of a receiving body of the gland, a coaxial annular groove being formed in the process.

[0067] Following the processing station or the method step, as shown in the illustration of FIG. 1a, a processing station and/or a method step can be reached or executed as illustrated in FIG. 2a, for example after blank 3 has been ejected via plunger 2.3. In this step or at this station, a blind hole 7 is also formed from an upper side 11 of head or screw head 4 facing away from shaft 5 using a corresponding two-piece tool 1 in an ultimately known manner, blind hole 7 extending toward shaft 5 and comprising at least the first section illustrated in the processing station and/or in the method step of FIG. 2a, the first section preferably having a polygonal cross section, preferably for receiving a screw tool for screwing in the gland. For this purpose, deforming tool 2.2 also comprises or again comprises a stamp 8, which is imprinted in screw head 4 and subjacent shaft 5 from the side of upper side 11 of head or screw head 4, leading to the cross section of end section 12 of stamp 8 being produced as the first cross section or as a cross section of a first section 13 of bling hole 7. Moreover, receiving tool 2.1, which is of a one-piece design with the exception of plunger 2.3, has surfaces extending parallel to axial direction A so that shaft 5 of blank 3 is formed to a cylindrical, in particular a circular-cylindrical, shape starting from the tapered shape, as illustrated in FIG. 1b, by producing first section 13 of blind hole 7.

[0068] In FIG. 2b, corresponding blank 3 is illustrated in an enlarged view. On the one hand, a first section 13 of a blind hole 7 can be discerned, which extends from upper side 11 of screw head 4 toward shaft 5. In addition, cross section Q1 of first section 13 of blind hole 7 is discernable in FIG. 1b, which is preferably designed to receive a screw tool. In addition, it can be discerned in the illustration of blank 3 according to FIG. 2b that shaft 5 has taken up an essentially cylindrical outer contour, which is ensured by at least indirectly displacing material from the area of first section 13 of blind hole 7 and by a corresponding design of receiving tool 2.1. The cylindrical shape or outer contour of shaft 5 of screw blank 3 enables ejecting again screw blank 3 using a plunger 2.3 allocated to receiving tool part 2.1 following the processing or the processing step of the illustration of FIG. 2a, in particular without other parts of receiving tool part 2.1 having to be changed, in particular having to be disassembled into several pieces or subgroups.

[0069] Sealing surface 10 already supplied or preformed in blank 3 of FIG. 1b and disposed on underside 9 of head or screw head 4 is also retained or further defined by the processing station of FIG. 2a.

[0070] FIGS. 3a and 3b show a processing situation or a processing station of the method according to the invention where the subsequent method step according to the invention is executed. Accordingly, FIG. 3c shows a blank of a gland or a gland itself which represents the result of the method according to the invention, i.e., a blank 3 according to the invention or a gland according to the invention. In the method step of FIG. 3a, again using a deforming tool part 2.2, blind hole 7 already formed in screw blank 3 is deepened by a second section 14, which borders first section 13, which is also attained by a correspondingly formed stamp 8 of deforming tool part 2.2. Second section 14 of blind hole 7 has a second cross section Q2, which is smaller with respect to first cross section Q1, i.e., to cross section Q1 of first section 13 of blind hole 7.

[0071] At least by indirectly displacing material from at least second section 14 of blind hole 7, an undercut 15, which is disposed at the crossover between shaft 5 and head 4 of blank 3, is further formed in shaft 5 of the gland or blank 3 of the gland. Undercut 15 aids attaining an improved imperviousness of the gland in particular without machining. The illustration of FIG. 3a indicates and the enlarged illustration of section Z of FIG. 3a in FIG. 3b clearly depicts that shaft 5 is widened at least in an area 16 opposite the screw head at least by indirectly displacing material from second section 14 of blind hole 7 within the scope of forming or producing second section 14 of blind hole 7. In addition, it is discernable in particular in FIG. 3b that a part of the widened section of shaft 5 abuts against radial deforming tool part 2.4 of receiving tool part 2.2, i.e., in particular in widened area 16, after the subsequent method step has been terminated, which is depicted in FIGS. 3a and 3b; in contrast, the part of shaft 5 forming undercut 15 has an increasingly larger distance in axial direction A toward head or screw head 4 with respect to radial deforming tool part 2.4. This distance, which is formed between blank 3 and radial deforming tool part 2.4, becomes increasingly larger toward head or screw head 4 and can be discerned particularly clearly in FIG. 3b, forms the deviation according to the invention from the hitherto known cold extrusion methods, where a corresponding complete abutment with a radial deforming tool part 2.4 had been presumed by necessity.

[0072] On the one hand, this enables that a widened portion in area 16 and consequently undercut 15 can be produced; simultaneously, however, end side or end face 6 can have a flat or otherwise arbitrarily formed, in particular a protrusion that protrudes away from head or screw head 4, while blank 3, in particular after second section 14 of blind hole 7 has been formed or impressed, can still be removed, in particular ejected, from receiving tool part 2.2, in particular from radial deforming tool part 2.4, by a plunger 2.3 without affecting undercut 15 or widened area 16 in the process nor receiving tool part 2.2, in particular radial deforming tool part 2.4, having to be opened or split in radial direction A.

[0073] In the subsequent method step, as exemplarily illustrated in FIGS. 3a and 3b, a gland or a gland blank 3 having a flat end face or end side 6 is accordingly produced, which additionally has a widened portion of shaft 6 giving grounds to undercut 15, does in particular not require machining blank 3 for forming undercut 15 and overall allows producing blank 3 by means of the cold extrusion method. In the example of FIG. 3c, blind hole 7 also comprises an advantageous third section 17, which abuts against second section 14 or borders second section 14, which is concentric to first and/or second section 14 of blind hole 7 and forms a cone segment, which tapers in direction A of shaft 5 and in particular ends in a flat bottom 18 of blind hole 7, which extends parallel to upper side 11 of head or screw head 4.

[0074] Preferably, the widening of shaft 5, in particular in area 16 of the maximum widening, can be 3% to 9%, preferably 5% to 7%, of the not widened diameter of shaft 5 in order to particularly advantageously introduce, in particular cut, a corresponding thread in shaft 5, thus mostly completing the process of turning blank 3 into a gland. The not widened diameter of shaft 5 or the shaft diameter can, for example, be determined based on the shaft diameter of FIG. 2b or the shaft diameter of FIG. 3c at the crossover between shaft 5 and head or screw head 4. As can be discerned in the illustration of FIG. 3c, bottom 18 of blind hole 7 extends up to approximately 75% of the overall height of the screw or screw blank 3, the overall height being determined between end face or end side 6 on the one hand and upper side 11 of head or screw head 4 on the other hand. In addition, bottom 18 of blind hole 7 is formed or disposed in such a manner that bottom 18 is formed in an area 16 of maximum radial widening in axial direction A. This advantageously causes forming the flank or tapering, which in turn causes blind hole 5 to be formed or at least prompts it.

[0075] In FIGS. 4 and 5, an exemplary embodiment of the invention is described which refers to a screw element designed as a screw nut or nut and to the corresponding production or the corresponding production method. Individual features, method steps or properties can, however, also be used for the previously described production of a screw element or a screw element blank for a gland. The individual stages of the screw element blank are illustrated in different views in both FIGS. 4 and 5. Concerning the tools used for the forming, reference is made to the illustrations of FIGS. 1 to 3 regarding the principles. This means that the blank is formed according to FIGS. 4 and 5, at least in as far as it is illustrated, using method steps of cold working, in particular cold extrusion.

[0076] In the illustration of FIG. 4, the stages of the screw element blank during the production of a blank of a nut or a screw nut are illustrated in the sequence of the processing or deforming steps from left to right, each method step or stage being shown in a perspective view and along a perspective cutting plane. In the first three stages, a cylindrical base body 19 is formed in such a manner that it has a head 4 and a shaft 5 bordering on head 4. It can be discerned that shaft 5 does not have a flat or smooth surface on its end side 6 facing away from the head but rather a slight contour, which essentially serves for centering the blank within the scope of the correspondingly following processing or method steps.

[0077] In the fourth illustrated stage or method step, a blind hole 7 or rather a first section 13 of a blind hole 7 is produced in the area of head 4 of the blank.

[0078] In the following method step, on the one hand, first section 13 of blind hole 7 is further formed or deepened in the area of head 4, while simultaneously an outer tool engagement portion 21 is formed on outer circumference 20 of shaft 4, a burr 22 being produced in the area of head 4 of the screw element blank when forming outer tool engagement portion 21. In the following method step or stage of screw element blank 3, burr 22 is on the one hand deburred, while simultaneously a second section 14 of blind hole 7 is formed in such a manner that an area 16 facing away from or being opposite head 4 is created in the area of shaft 5, area 16 being radially widened by at least indirectly displacing material from second section 14 of blind hole 7 so that an undercut 15 is formed at the same time in an area of shaft 5 bordering on head 4. When observing end side 6 of shaft 5 facing away from the head, it becomes obvious that the profile of end side 6 is marginally changed. This change in the profile, however, is not sufficient to form undercut or turned-down portion 15. Equally, the change in the profile of end face 6 of shaft 5 is not significantly involved in at least indirectly displacing material which leads to forming undercut 15. The method according to the invention accordingly is to include methods where end side 6 of the shaft facing away from the head does not remain entirely unchanged, but is rather subject to smaller or minimal changes, which at the same time, however, do not have any or hardly any noticeable influence on forming the undercut. In turn, this means the undercut is produced almost exclusively by material being indirectly displaced within the scope of producing or forming the second section of blind hole 7 from the direction of head 4 of screw element blank 3 as intended by the method according to the invention.

[0079] In a last stage or method state of the method according to the invention for producing a screw element blank, FIG. 4 shows a step for producing a hole, where a screw opening 23 is formed from blind hole 7 by stamping or punching, screw opening 23 being produced in such a manner that undercut 15 remains largely untouched in the crossover area between shaft 5 and head 4. For this purpose, the stamping or punching is carried out from the side of head 4 toward shaft 5, for example. In order to produce a nut or a screw nut according to the invention from screw element blank 3 as intended by the last stage or method step of FIG. 4, it can be further envisioned that an inner thread is formed, in particular cut, in the area of screw opening 23. It can also be envisioned that a washer is disposed in the area of undercut 15 captively or so that it cannot be lost.

[0080] FIG. 5 shows the stage process of FIG. 4 in lateral sectional illustrations and at least partially in top views on screw element blank 3. The lateral sectional illustrations show clearly that the widening of lower area 16 of shaft 5 or area 16 of shaft 5 facing away from head 4 can turn out to be comparatively low and the prominence of undercut 15 turns out to be accordingly low as well. This is owed to the fact that undercut 15 merely serves for fastening or disposing a washer captively or in such a manner that it is secured against loss.

[0081] Furthermore, the sectional illustration of the side views of FIG. 5 shows that second section 14 of blind hole 7 or entire blind hole 7, which is produced by at least indirectly displacing material for forming the undercut, is almost entirely disposed in the area of head 4. Contrary to the exemplary embodiment of the gland according to FIGS. 1 to 3, this means that blind hole 7 does not or at least not significantly enter the area of shaft 5, let alone an area of maximum widening of the shaft. Forming second section 14 in the area of head 4 shown in FIG. 5 is already sufficient, however, for producing undercut 15 via correspondingly indirectly displacing material and widening shaft 5 in area 16.

[0082] The lateral sectional illustrations of FIG. 5, in particular in comparison to the fifth and sixth stages or method steps, show that the additional deforming of end face 6 of shaft 5 does not add or only negligently adds anything to forming undercut 15. The deformation in the area of end face 6 indeed serves for centering blank 3 for the subsequent processing or deforming steps and for preparing for forming the screw hole or screw opening 23, which is produced by a corresponding punching or stamping according to the illustration of the last stage of FIG. 5.

[0083] FIG. 6 shows different views of a washer 24 or a sliding disk, which in conjunction with a screw element blank 3 according to FIGS. 4 and 5 can be assembled to a nut, where washer 24 is disposed in the area of shaft 5 so that it cannot be lost. In the lateral view of washer 24, it can be discerned that dogs 25, which are oriented radially inward, are formed in the inner circumference and are partially set back, are bent upward or out of the washer plane. This deformation of the dogs or the deformed state of the dogs achieves that a uniform inner diameter is also attained in the area of dogs 25 or even an inner diameter which is slightly larger than the other inner diameter of the washer is attained in the area of dogs 25. This can be discerned in the top view on washer 24 of FIG. 6, for example.

[0084] In the deformed state of dogs 25, the inner diameter, however, is chosen such at each location that it is at least slightly larger than the widened section of a corresponding screw element or blank. Consequently, the washer can be slid across this section of the shaft and be moved to the head or into the area of the undercut. As soon as the washer is disposed in the area of the undercut, dogs 25 can be deformed, in particular returned, into or back into the plane of the washer by a deforming tool, whereby they realize a reduced inner diameter in the area of dogs 25.

[0085] This leads to the inner diameter of washer 24 being smaller at least in sections owing to returned dogs 25 than the outer diameter of widened area 16 of shaft 5. This ensures washer 24 is disposed so that it cannot be lost at screw element 3, in particular the nut.

LIST OF REFERENCE NUMERALS

[0086] 1 tool [0087] 2 tool parts [0088] 2.1 receiving tool part [0089] 2.2 receiving tool part [0090] 2.3 plunger [0091] 2.4 deforming tool part, radial [0092] 3 blank [0093] 4 head/screw head [0094] 5 shaft [0095] 6 end side [0096] 7 blind hole [0097] 8 stamp [0098] 9 underside [0099] 10 sealing surface [0100] 11 upper surface [0101] 12 end section [0102] 13 first section [0103] 14 second section [0104] 15 undercut [0105] 16 area [0106] 17 third section [0107] 18 bottom [0108] 20 outer circumference [0109] 21 outer tool engagement portion [0110] 22 burr [0111] 23 screw opening [0112] 24 washer [0113] 25 dog [0114] A axial direction [0115] Q1 first cross section [0116] Q2 second cross section