Threaded parts that are screwed into plastic

Abstract

A threaded fastener (10) for cutting a mating thread into a plastic article, comprising a lower thread portion (F) and an upper thread portion (T), the lower thread portion having a larger diameter than the upper thread portion, and the area occupied by the crests of the lower thread portion being larger than that of the upper thread portion. [Selected Figure] Figure 1

Description

[Technical field]

[0001] The invention relates to a threaded fastener, in particular for screwing into plastics, according to the preamble of claim 1. [Background technology]

[0002] US Patent No. 5,795,120 describes a threaded fastener for insertion into a member having a pilot hole, the fastener having a forming thread region and a support thread region, the thread profile of the forming thread region being relatively larger than the thread profile of the support thread region.

[0003] A disadvantage of this configuration, particularly when the threaded fastener is used in plastics, is that a large pitch and small flank angle result in high loads on the components. Summary of the Invention

[0004] An object of the present invention is to provide a threaded fastener which can reduce the mechanical load on a member with a small tightening torque and achieve a high pull-out value.

[0005] The above problem is solved by a combination of the features of the characterizing portion of claim 1 and the generic concept of the same claim.

[0006] Advantageous refinements of the invention are described in the dependent claims.

[0007] As is known, a threaded fastener comprises a threaded fastener central axis, a drive portion, and a threaded shank. The shank has at least one thread (a single thread or groove) that extends along the shank in a helical manner of at least locally constant pitch to form a main thread having a varying profile profile, the main thread having an average thread radius over its length. The profile profile is defined by a cross-section of the thread in a cross-sectional plane of the helix, the cross-sectional plane including the threaded fastener central axis. The thread radius is the maximum orthogonal distance from the threaded fastener central axis to the profile profile of the thread. The main thread has a support region and a forming region, the forming region being provided with a forming profile profile having a forming region radius, and the support region being provided with a support profile profile having a supporting region radius.

[0008] The forming profile contour is defined by the projection of the thread along the helix, in particular by projecting the thread over an axial extension of three times the average thread radius from the free end of the shank in the direction of the drive onto a cross-sectional plane of the helix that contains the central axis M of the threaded component. This projection corresponds to the projection of a linear extension of the thread onto a cross-sectional plane of the helix that contains the central axis M of the threaded component. This results in a forming profile contour with a maximum extent, which corresponds to the effective forming profile contour. This forming profile contour has a maximum perpendicular distance to the central axis of the threaded component, which defines the forming zone radius.

[0009] The forming region is the helix whose maximum extent of the forming profile contour closest to the driver is 85% of the average thread radius radially outward. from Range To At some point, the next profile contour will end before it again lies within the forming profile contour.

[0010] The support profile contour is obtained by projecting the thread along the helix, in particular in the direction of the drive, onto a cross-sectional plane of the helix over an axial extension range starting at a distance of 2 / 3 of the average thread radius from the end of the forming zone and ending at a distance of 5 / 3 of the average thread radius. This range corresponds to at least one partial region of the support zone. This range can extend further along the main thread in the direction of the drive, provided that the profile contour does not exceed the support profile contour. This support profile contour has a maximum perpendicular distance to the central axis of the threaded component, which defines the support zone radius.

[0011] Such an arrangement ensures that the transition area from the forming area to the support area is as short as possible while still providing a support area that is sufficiently long to perform the basic retention function of the threaded fastener.

[0012] Furthermore, the support profile contour and the forming profile contour are adjusted to one another so that when the support profile contour and the forming profile contour overlap along the spiral at least in the range extending radially outward from a position at 85% of the forming region radius, the support profile contour is completely contained within the forming profile contour.

[0013] With this configuration, the elastic return of the material in the cut female thread portion is taken into consideration, and the tightening torque can be kept small.

[0014] In the present invention, the forming profile contour defines a forming profile surface, the forming profile surface being measured radially inward from the location of the maximum orthogonal distance from the forming profile contour to the central axis of the threaded component within a range of 10% of the forming region radius, and the forming profile surface is larger than a support profile surface defined by the support profile contour and measured radially inward from the location of the maximum orthogonal distance from the support profile contour to the central axis of the threaded component within a range of 10% of the forming region radius.

[0015] The profile contour adjustment of the invention as described above makes it possible to realize a compensation of the elastic return in the female thread even in the case of relatively small flank angles and to ensure that the flanks are sufficiently covered, thus preventing damage to the component material, such as for example in the case of threaded components with a proportionally enlarged forming area thread.

[0016] Preferably, the forming profile contour and the support profile contour have a flank angle of less than 35°. The flank angle of the forming profile contour is parallel to the threaded component axis and has a forming profile radius R F 85% position and the corresponding forming profile radius R F The sum of the two base angles of a trapezoid formed by using the intersection line at the 95% point as its bases is equal to 180° minus the sum of the two base angles of the trapezoid. The base angle is the angle at the longer base of the trapezoid, i.e., the angle at the intersection line at the 85% point.

[0017] The rules for measuring the flank angle of the support profile contour are similar and, in the case of the support profile contour, the support profile radius R T and the support profile radius R T Place the intersection line at the 95% point.

[0018] The flank angle is in particular between 20° and 30°, which is a flank angle that has proven to be suitable for plastic screw fastenings.

[0019] In a preferred refinement of the invention, the support zone radius is 1% to 3% smaller than the forming zone radius, so that the material damage caused to the plastic component is as small as possible and at the same time the distance between the forming profile contour and the support profile contour corresponding to the elastic return of the material is sufficiently large.

[0020] It is particularly preferred that the axial width of the support profile contour at a location near 95% of the support zone radius is smaller than the axial width of the forming profile contour at a location near 95% of the forming zone radius, which allows the thread profile to have a simple shape and allows the forming profile surface to be larger than the support profile surface.

[0021] In particular, the width of the support profile contour is at least 10% smaller, in particular at least 20% smaller, than the width of the forming profile contour.

[0022] For easier manufacture, the forming profile contour and / or the support profile contour may be symmetrical.

[0023] In one particularly preferred embodiment, the formed region is less than 2x pitch. Preferably, the threads increase to the formed profile contour and then remain constant over the length of the formed region to the end.

[0024] Preferably, the ratio of the groove bottom radius to the average thread radius is 0.6 to 0.8, which is the usual ratio in plastic screw fastening.

[0025] In a further refinement of the invention, at least a portion of the support profile contour can lie outside the forming profile contour within 85% of the forming zone radius in the radial direction, which allows a more flexible configuration of the flank transition to the thread groove root, which allows better consideration of the material properties.

[0026] More preferably, the groove bottom diameter of the forming region can be set to be equal to or smaller than the groove bottom diameter of the supporting region.

[0027] In another preferred embodiment of the present invention, the free end of the shank of the threaded component can be provided with a tap thread having at least two tap threads, the radius of which is up to 90% of the radius of the forming region and which constitutes the tap region.

[0028] The tap thread region is formed where the at least two tap threads have the same diameter progression and where the thread radius of the main thread is less than or equal to the thread radius of the tap thread.

[0029] This arrangement allows a particularly straight cutting of the threaded fastener, so that the female thread cut into the plastic part by the subsequent forming region and the thread of the support region following the forming region can be aligned as accurately as possible and the elastic return of the plastic can be accurately taken into account. In this way, friction in the support region during tightening can be further reduced or even prevented.

[0030] Preferably, the thread radius of the lead thread in the tapping region is equal to the thread radius of the tapping thread at the same axial distance to the free end of the shank of the threaded fastener, whereby the at least two tapping threads, in particular the two tapping threads, and the lead thread create at least three identical cut points, which allow a particularly straight application of the threaded fastener.

[0031] Preferably, all threads in the tap region have their origin in the same cross-sectional plane. Furthermore, all threads in the tap region have the same cross-sectional profile and therefore are of similar configuration. For example, the main thread and the two tap threads start in the same way and follow similar paths.

[0032] Alternatively, at least three tap threads can also be provided, in which case the thread radius of the main thread in the tap area is in particular smaller than the radius of the tap thread.

[0033] In one preferred refinement of the invention, the tap threads start at the flute root and the radius of the tap threads increases continuously from the flute root to the end of the tap area, thereby allowing a continuous and uniform cut into the threaded fastener.

[0034] Additionally, the threads can be evenly distributed around the circumference of the tap area with equal thread radii and equal axial heights, providing symmetrical application to the pilot hole in the plastic member.

[0035] In particular, the diameter of the free end of the fastener is at least 20%, at least 30%, at least 40%, at least 50%, at least 60% of twice the radius of the formed area. Such truncated tips are common in threaded fasteners for plastics.

[0036] The tap thread can be connected directly to the free end of the fastener, which allows for ideal guiding of the fastener at the first cut.

[0037] Alternatively, the beginning of the tap thread can be spaced apart from the free end of the fastener, so that the area up to the end of the fastener can perform a locating function.

[0038] To simplify manufacture, the tap threads and the main threads may be rolled threads.

[0039] In another preferred embodiment, the flank angle of the threads in the tap area can be greater than the flank angle of the lead threads outside the tap area, which has the advantage of providing good centering without undercutting one side of the tap threads and can facilitate repeated installation.

[0040] The tap threads may terminate abruptly at the end of the tap region, which has the advantage of minimizing friction as the fastener is further turned into the narrow pilot hole.

[0041] In another preferred refinement, the tap threads can span up to two turns, which promotes efficient tightening while still ensuring optimal orientation of the threaded fastener.

[0042] A thread may have a break in the thread, provided that the interpolated progression of the thread radius remains unchanged.

[0043] Another aspect of the invention relates to a method for manufacturing a threaded connection with the above-mentioned inventive threaded fastener. The inventive threaded fastener is rotated into a prepared hole in a plastic part, and in the forming area a mating thread or an internal thread having a formed profile contour is cut into the plastic. As soon as the mating thread is no longer engaged in the forming area, it springs back in the support area, so that the internal thread does not come into straight contact with the thread in the support area during the tightening process. Only by finally tightening the threaded fastener into the part is the thread in the support area pressed against the mating thread.

[0044] Preferably, the fastener of the present invention is tightened into a pilot hole having a radius that corresponds to about 80% of the radius of the forming area.

[0045] The invention further relates to a threaded connection manufactured by the above method.

[0046] Further advantages, configurations and possible applications of the invention will become apparent from the following description and from the exemplary embodiments shown in the drawings. [Brief description of the drawings]

[0047] [Figure 1] FIG. 2 is a side view of the threaded fastener of the present invention. [Diagram 2] FIG. 2 is a perspective view of the thread in an extended state. [Figure 3a] This is a perspective view of the thread stretched over 3×RM. [Figure 3b] FIG. 1 is a front view of the thread in an extended state. [Figure 3c] FIG. 13 shows the formed profile contour obtained by projecting the stretched threads. [Figure 4]FIG. 13 is a perspective view showing the state in which the threads are extended, together with an image of the end of the forming region. [Figure 5a] FIG. 13 is a perspective view showing the threads of the support region stretched out; [Figure 5b] FIG. 1 is a front view of the thread in an extended state. [Figure 5c] FIG. 13 is a diagram showing the support screw portion profile obtained by projection. [Figure 6] 3c and the supporting thread profile of FIG. 5c are superimposed. [Figure 7] FIG. 7 is an enlarged view of the overlap of FIG. [Figure 8a] FIG. 2 shows a forming profile surface. [Figure 8b] FIG. 1 shows a support profile surface. [Figure 9] FIG. 1 illustrates the forming profile flank angle. [Figure 10] FIG. 13 is a diagram showing the forming profile contour superimposed with the supporting profile contour. [Figure 11] FIG. 13 is a diagram showing the forming profile contour superimposed with the supporting profile contour. [Figure 12] FIG. 2 is a side view of a threaded fastener of the present invention having a tap thread portion. [Figure 13a] FIG. 13 is an enlarged view of the tap area of ​​FIG. [Figure 13b] FIG. 13 is a cross-sectional view of the tap area. [Figure 13c] FIG. 13 is another cross-sectional view of the tap area. [Figure 13d] FIG. 13 is a cross-sectional view of a threaded component shank outside the tapping area. [Figure 14] FIG. 2 is a side view of the threaded connection of the present invention. [Figure 15a] FIG. 15 is an enlarged view of the formed thread area of ​​FIG. [Figure 15b] FIG. 15 is an enlarged view of the support screw area of ​​FIG. 14. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] 1 is a side view of a threaded fastener 10 of the present invention having a threaded fastener central axis M, a driver portion 12, and a threaded shank portion 14. The direction of the threaded fastener central axis M is hereinafter referred to as the "axial direction." The shank portion 14 is provided with at least one thread 16 which extends helically along the shank portion at a constant pitch to define a lead thread 18 having a varying profile contour 20. The lead thread 18 has an average thread radius R along its length. M The average thread radius R M is the average thread radius in the main thread 18, which is usually between the forming zone radius and the support zone radius. Therefore, the average thread radius R M will be approximately equal to the nominal radius.

[0049] The profile contour 20 is defined by a cross-section of the threads at a cross-sectional plane H of the helix that includes the central axis M of the threaded component.

[0050] Thread radius R is defined as the maximum perpendicular distance from the threaded component centerline axis M to the profile contour 20 of the threads 16, as will be explained in more detail in FIG. 3a.

[0051] The main thread portion 18 has a support region T and a forming region F, and in the forming region, a forming region radius R F A forming profile contour 24 having a support region radius R is obtained. T A support profile contour 22 having the following structure is obtained:

[0052] The forming profile contour 24 extends from the free end of the shank 25 along the helix to three times the average thread radius (3×R M ) into the cross-sectional plane H of the helix, as will be explained in more detail in FIG. 3c.

[0053] Therefore, the above projection corresponds to a projection of the thread extended in a straight line onto the cross-sectional plane H of the helix that includes the central axis M of the threaded part.

[0054] 2 is a diagram showing a side view of the screw fastener 10 together with the screw fastener central axis M. In the screw fastener 10, a 3×R M Extending the axial extent of the threaded fastener over its axial length, here it is the length L1. Also shown is a cross-sectional plane H that contains the threaded fastener central axis M.

[0055] A perspective view of the thread 16 in an extended state is shown in FIG. M 1 shows a schematic representation of thread 16 having a length L1 corresponding to the length of thread 16 when the axial extent of thread 16 is extended. Radius R is shown by dotted lines at various points on thread 16. In this way, the average thread radius over the entire length of main thread 18 is determined.

[0056] Figure 3b shows a front view in the extended state, which corresponds to the cross-sectional plane of the helix. By projecting onto this cross-sectional plane, the forming profile contour 24 shown in Figure 3c is obtained at its maximum extent, which is the effective forming profile contour 24 that will later form the internal thread in the part.

[0057] The forming region F ends at the forming region end FE. That is, the main thread portion 18 has a length of 3×R M The maximum extent of the formed profile contour 24 immediately adjacent to the driving portion is 85% of the average thread radius radially outward before the next profile contour in the range of the end of L1, which is the length of the thread corresponding to from Range To The forming region end FE is shown in FIG. 4. This is the last place the forming profile contour 24 appears from the beginning of the thread before the profile contour transitions after the transition region into the support profile contour 22, which in this case is maintained the rest of the threaded component length for the main thread 18.

[0058] The support profile contour 22 extends from the forming area end FE to the average thread radius R MThe starting point is the vicinity of the position of 2 / 3 of the axial distance from the forming area end FE to the average thread radius R M L2 is obtained by projecting onto the cross-sectional plane H of the helix the portion of the thread 16 extending in an axial direction along the helix, the end point of which is approximately 5 / 3 of the axial distance of the thread 16. This range corresponds to at least one partial area of ​​the support area T. In FIG. 4, the range obtained with the same axial dimensions as those mentioned above is shown in the state where the threaded portion 18 is extended. L2 is 2 / 3×R M The length L3 is the length of the thread 16 obtained by extending the axial range of the thread 16. The length L3 is 5 / 3 x R M 2 is the length of the thread 16 obtained by extending the axial extent of the thread 16.

[0059] In this way, the start point of the range for determining the support profile contour 22 is set to 2 / 3×R M By setting the length of the transition region from the forming region F to the supporting region T at approximately 2 / 3×R, it is ensured that the transition region from the forming region F to the supporting region T is as short as possible. This ensures that the transition region is shorter than L2 in the stretched state and is axially longer than 2 / 3×R. M In the stretched state, the support region T has a length of at least L3-L2, which fulfills the basic holding function of the threaded fastener. The stretched state of the part of the thread 16 which constitutes at least part of the support region is shown in FIG. 5a. FIG. 5b shows a front view in the stretched state, and FIG. 5c shows the corresponding projection of this stretching into the cross-sectional plane H of the helix, which determines the support profile contour 22. The front view and the projection are identical in the present case, since the profile contour of the support region invariably coincides with the support profile contour 22 in the present case.

[0060] 6, the support profile contour 22 and the forming profile contour 24 are arranged along a spiral at least at a forming region radius R FThe support profile contour 22 and the forming profile contour 24 are adjusted to one another in such a way that the support profile contour 22 fits completely within the forming profile contour 24 when they overlap in a range E extending radially outward from about 85% of the axial length of the forming profile contour 24. An enlarged view of the range E is shown in FIG. 7. The distance A1 between the flank of the forming profile contour 24 and the flank of the support profile contour 22 can be adjusted to the elasticity of the material but is advantageously 0.03 mm to 0.05 mm, in particular 0.04 mm, for example for a threaded fastener with a nominal diameter of 5 mm. This distance is preferably constant over one flank at least within the range E.

[0061] 8a is an enlarged view of a region E of the forming profile contour 24, which bounds a forming profile surface 26, which is measured radially inward from the maximum perpendicular distance from the forming profile contour to the threaded component central axis within 10% of the forming region radius. FIG. 8b is an enlarged view of a region E of the support profile contour 22, which bounds a supporting profile surface 28, which is measured radially inward from the maximum perpendicular distance from the supporting profile contour to the threaded component central axis within 10% of the forming region radius. F The maximum orthogonal distance is measured within a range of 10% of R T is equivalent to.

[0062] In the present invention, the forming profile surface 26 is larger than the supporting profile surface 28. The advantage of such a configuration is that a sharp flank angle can be achieved without excessively loading the material into which the threaded fastener is fastened, thereby achieving high pull-out forces with low tightening torques.

[0063] The flank angle α of the forming profile contour 24 is defined as shown in FIG. 9. The flank angle α is parallel to the threaded component axis and is spaced apart from the forming profile radius R F 85% position and the corresponding forming profile radius R FThe sum of the two base angles (β1, β2) of the trapezoid formed by using the intersection line at the 95% position as the bases is equal to 180° minus the sum of the two base angles (β1, β2). The base angle is the angle at the longer base of the trapezoid, i.e., the angle at the intersection line at the 85% position.

[0064] The flank angle is less than 35°, particularly between 20° and 30°.

[0065] The rules for the measurement of the flank angle of the support profile contour 22 are similar, and in the case of the support profile contour, the support profile radius R T Place intersecting lines at the 85% and 95% positions.

[0066] FIG. 10 shows the width B of the forming profile contour at 95% of the forming radius. F and the width B of the support profile contour T A comparison diagram of the width B of the formed profile contour 24. F is the width B of the support profile contour 22 here T In the example of FIG. 10, the width B T is the width B of the forming profile contour 24 F The forming profile contour 24 and the supporting profile contour 22 are both symmetrical in this case. The axis of symmetry is a line perpendicular to the central axis M of the threaded component and the half-width B of each profile contour 22, 24. T Or B F are perpendicular lines intersecting at

[0067] 11 shows another embodiment of the support zone T of the threaded portion, in which the transition from the thread flank to the thread groove root is flatter than the transition from the thread flank to the thread groove root in the above-described figures. In this embodiment, the support profile contour 22 is located at least partially outside the forming zone contour 24 within 85% of the forming zone radius in the radial direction.

[0068] 12 shows another embodiment of a threaded fastener according to the present invention, the shank of which further includes a tap thread 30 at its free end. The tap thread has at least two tap threads 32, 34, the radii of which are up to a forming zone radius R F 90% of the total length of the tap threads 32, 34, which constitute the tap region AB in which the tap threads 32, 34 have the same radial progression throughout their helix, and moreover, at the same axial distance from the free end 25 of the threaded fastener, the thread radius of the main thread is less than or equal to the thread radius of the tap threads.

[0069] In this case, the threads 16 of the main thread 18 in the tapping region have the same thread radius R as the tapping region 30 at a location that is the same axial distance from the free end of the fastener as the tapping region 30. The tapping threads 32, 34 begin at the bottom of the flute, directly at the free end 25 of the fastener shank. This arrangement allows for ideal guiding of the fastener as soon as it is first cut in. The tapping region 30 in this case extends over approximately one full turn, and the tapping region ends approximately one-third of a turn.

[0070] The diameter of the free end of the threaded component shank is the forming area radius R in this case. F This is at least about 65%, or twice as much.

[0071] The tap areas are detailed in Figures 13a-13d.

[0072] FIG. 13a is an enlarged side view of the free end 25 of the threaded fastener shank, showing three cross-sections. The first cross-section PP is located in the middle of the tapping area AB. The cross-section QQ is located at the end of the tapping area AB, and the cross-section SS is located above the tapping area. FIG. 13b shows the cross-section at the cross-section PP. In FIG. 13b it is clearly visible that all threads of the tapping area, i.e. both tap threads 32, 34 and the thread 16, have the same thread radius. The same is true for the end of the tapping area in FIG. 13c, where again all present threads 16, 32, 34 have the same thread radius R at the same axial distance from the free end of the threaded fastener axis.

[0073] Finally, Fig. 13d shows, in a cross-section at the cross-sectional line SS, the thread radius of the thread 16 of the main thread outside the tapping region AB and the thread radius of both tap threads 32, 34. In this region, the thread radius R of the tap threads 32, 34 is significantly smaller than the thread radius of the thread 16 of the main thread 18 at this cross-sectional line. In the present case, the tap threads end with a fade-out after the tapping region, whereas the threads of the main thread continue to increase further until they reach their forming profile contour.

[0074] FIG. 14 is a cross-sectional view of the screw connection 40 during fabrication.

[0075] The threaded connection 40 comprises a threaded fastener 42 and a plastic part 46 having a pilot hole 44. A forming area F in front of the threaded fastener 42 pre-cuts a thread in the plastic part 46, which then engages the next support area T of the thread. Figure 15a shows detail 1, which shows the engagement of the thread in the forming area F, and detail 2, which shows the engagement of the thread in the support area of ​​the main thread.

[0076] The forming profile contour 50 is shown in FIG. 15a. The following thread with the support profile contour 58 in the support region of the threaded fastener is shown in detail in FIG. 15b. In the detail of FIG. 15b, the elastic return of the threads of the female thread is shown by the contour line 56. In this figure, despite the elastic return of the female thread, the thread flank of the support profile contour 58 and the elastically returned female thread are still separated by a distance A2. This allows the thread of the support region to be screwed into the female thread almost frictionlessly. Only by finally tightening the threaded fastener 42 is the thread of the support region pressed against the flank of the female thread and a frictional connection is formed in the direction of rotation. The area of ​​the tip region of the support profile contour 58 is smaller than the area of ​​the forming profile contour 50, which allows a small tightening torque and ensures a high pull-out resistance, since material damage to the plastic material is avoided and a sufficient distance of the thread flank is available between the elastically returned female thread and the thread of the support region.

Claims

1. A threaded fastener (10) having a threaded fastener central axis (M), The device includes a drive portion (12) and a threaded shaft portion (14) having a screw thread (16), The threads (16) extend helically along the shank at least locally at a constant pitch to form a main thread (18); The main thread (18) has an average thread radius (R Ｍ ), where thread radius (R) is the maximum perpendicular distance from the threaded component axis (M) to the thread profile contour (20); The main thread portion (18) has a support region (T) and a forming region (F), The formation region (F) has a formation region radius (R Ｆ ) is obtained, and the support region (T) has a support region radius (R Ｔ ) is obtained, The forming profile contour (24) extends from the free end (25) of the shank along the helix along the mean thread radius (R Ｍ ) over an axial extent three times the length of the helix, the forming region (F) ends at a point of the helix where the forming profile contour (24) is in a range from 85% of the average thread radius radially outward and closest to the driver, except that, closer to the driver than the point of the helix, the profile contour (20) lies within the forming profile contour (24); The support profile contour (22) extends along the helix from the end (FE) of the forming area to the mean thread radius (R Ｍ ) and the average thread radius (R Ｍ ) on the cross-sectional plane (H) of the helix, The support profile contour (22) and the forming profile contour (24) are at least Ｆ 2. A threaded fastener (10) in which the support profile contour (22) is completely contained within the forming profile contour (24) in a range extending radially outward from a position at 85% of the forming region radius (R F ), when the support profile contour (22) and the forming profile contour (24) overlap in a range extending radially outward from a position at 85% of the forming region radius (R F ), A formed profile surface (26) bounded by the formed profile contour (24), the formed area radius (R Ｆ ) is a support profile surface (28) bounded by the support profile contour (22), the formed region radius (R ) being measured radially inward from the location of the maximum perpendicular distance from the support profile contour (22) to the central axis of the threaded component. Ｆ ) greater than the support profile surface (28) measured within 10% of A screw fastener characterized by:

2. the forming profile contour (24) and the supporting profile contour (22) have a flank angle (α) of less than 35°; The threaded fastener according to claim 1.

3. The support region radius (R Ｔ ) is the radius of the forming region (R Ｆ ) is 1% to 3% smaller than The screw fastener according to claim 1 or 2.

4. The support region radius (R Ｔ axial width (B) of the support profile contour (22) at 95% of the Ｔ ) is the formation region radius (R Ｆ The axial width (B) of the forming profile contour (24) at 95% of the Ｆ ) smaller than 4. A threaded fastener according to any one of claims 1 to 3.

5. The width (B Ｔ ) is the width (B Ｆ ) is at least 10% smaller than The threaded fastener according to claim 4.

6. the forming profile contour (24) and / or the support profile contour (22) are symmetrical about a line perpendicular to the central axis (M) of the threaded component; 6. A threaded fastener according to any one of claims 1 to 5.

7. The forming region (F) is smaller than twice the pitch of the threaded part, The thread (16) increases from the free end (25) of the shaft toward the end (FE) of the forming region up to the forming profile contour (24) and then remains constant throughout the range up to the end (FE) of the forming region.

7. A threaded fastener according to any one of claims 1 to 6.

8. The groove bottom radius and the average thread radius (R Ｍ ) is 0.6 to 0.

8.

8. A threaded fastener according to any one of claims 1 to 7.

9. The radius of the forming region (R Ｆ ), at least a portion of the support profile contour (22) is outside the forming profile contour (24) within a range of 85%.

9. A threaded fastener according to any one of claims 1 to 8.

10. The groove bottom diameter of the forming region is equal to or smaller than the groove bottom diameter of the supporting region (T); 10. A threaded fastener according to any one of claims 1 to 9.

11. The threaded fastener has a tap thread portion (30) near the free end (25) of the shank, The tap thread portion (30) has at least two tap threads (32, 34), and the radii of the tap threads (32, 34) are up to the forming region radius (R Ｆ 90% of the tap threads (32, 34) constitute a tap area (AB); in the tapping region (AB) the tapping threads (32, 34) have the same radial progression and in the tapping region (AB) the thread radius of the main thread (18) is less than or equal to the thread radius of the tapping threads (32, 34); 11. A threaded fastener according to any one of claims 1 to 10.

12. the main thread (18) has a thread radius (R) in the tap area (AB) equal to the tap threads (32, 34); The threaded fastener according to claim 11.

13. The tap threads (32, 34) are at least three; the thread radius (R) of the main thread (18) in the tap region (AB) is smaller than the thread radius of the tap thread; The threaded fastener according to claim 11.

14. the tap thread (32, 34) starts at the flute root and the thread radius (R) of the tap thread (32, 34) continuously expands in the direction of the support region (T); Threaded fastener according to any one of claims 11 to 13.

15. All threads (16, 32, 34) of the tap area (AB) are evenly distributed circumferentially with equal thread radii (R). Threaded fastener according to any one of claims 11 to 14.

16. The groove bottom diameter of the free end of the threaded fastener is at least 20%, at least 30%, at least 40%, at least 50%, or at least 60% of twice the radius of the formed area. Threaded fastener according to any one of claims 11 to 15.

17. all threads (16, 32, 34) of said tapping region (AB) have their origin in the same cross-sectional plane; Threaded fastener according to any one of claims 11 to 16.

18. All threads (16, 32, 34) of the tapping area (AB) have the same profile contour. Threaded fastener according to any one of claims 11 to 17.

19. The tap thread portion (30) is directly connected to the free end (25) of the shaft portion. Threaded fastener according to any one of claims 11 to 18.

20. The beginning of the tap thread portion (30) is spaced apart from the free end (25) of the shank.

20. A threaded fastener according to any one of claims 11 to 19.

21. The tap thread portion (30) and the main thread portion (18) are rolled thread portions. Threaded fastener according to any one of claims 11 to 20.

22. a flank angle of the thread in the tapping region (AB) is greater than a flank angle of the main thread (18) outside the tapping region (AB); Threaded fastener according to any one of claims 11 to 21.

23. The tap thread portion (30) terminates abruptly. Threaded fastener according to any one of claims 11 to 22.

24. The tap thread portion (30) has a maximum of two turns. Threaded fastener according to any one of claims 11 to 23.

25. 25. A method for producing a threaded connection comprising the threaded part (10, 42) according to any one of claims 1 to 24, the threaded fastener (42) is rotated and inserted into the pilot hole (44) of the plastic member (46) to cut a mating thread having the formed profile contour (50) into the plastic at the forming region (F), in response to which the mating thread returns elastically at the support region and does not come into straight contact with the thread at the support region (T) during the tightening process; The threaded portion of the support region (T) is pressed against the mating threaded portion only when the threaded fastener is tightened into the member. A manufacturing method comprising the steps of:

26. The radius of the pilot hole corresponds to 80% of the radius of the forming region. The method of claim 25.

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