Locking fastener

Claim 2

An externally threaded male locking fastener for engagement with an internally threaded female member, said female member having an internal thread which is of a substantially circular cross-section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered workentering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed Adjacent said tapered workentering end and including a plurality of thread turns of the radially relieved type, said plurality of thread turns having one flank thereof bulging outwardly at a first axial direction with the opposite flank of said thread turns depressed inwardly in said first axial direction, whereby upon engagement of said preparation portion, with the internal thread of a female member regardless of the industry tolerances employed, said internal threads will be reshaped and provided with uniform corresponding bulging and depressed flanks, deflected axially with regard to their initial configuration; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking portion including a plurality of thread turns having a thread form which will upon engagement with said uniformly reshaped axially deflected bulging internal threads, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 3

An externally threaded male locking fastener as defined in claim 1 wherein said locking thread portion includes a plurality of thread turns having relatively straight flank surfaces, disposed to engage said bulging flanks formed on said internal thread by the preparation portion, said engagement producing the desired flank interference.

Claim 4

An externally threaded male locking fastener as defined in claim 1, wherein said locking thread portion includes a plurality of locking thread turns having one flank thereof bulging outwardly in a second axial direction opposite to said first direction, with the oppositely disposed flank of said locking thread turn being depressed, such that upon engagement of said locking thread turn with said previously reshaped internal thread, flank-to-flank contact will be obtained between the opposed engaged bulging flanks of said internal thread and said locking thread, respectively, producing the desired flank interference.

Claim 5

A locking screw according to claim 1 further provided with a transition thread section located between and joining said preparation thread portion and said locking thread portion and having an intermediate thread flank configuration.

Claim 6

A locking screw according to claim 4 wherein said transition thread section is characterized by a substantially straight flank cross section.

Claim 7

A locking screw according to claim 1 wherein said bulging flank is convexly rounded and wherein said relieved flank is concavely rounded.

Claim 8

A locking screw according to claim 1 wherein said bulging flank extends angularly outwardly to an apex proximate the pitch cylinder of said screw while said relieved flank extends angularly inwardly to an apex also proximate the pitch cylinder of said screw.

Claim 9

An externally threaded locking fastener member adapted to be engaged with an internally threaded female member, having an internal thread formation which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said fastener member including a driving head, a shank portion and a tapered work-entering end, with an external thread formed on at least a portion of said shank, said external thread including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of sizing thread turns of the radially relieved type and having a standard profile, said sizing thread turns having an effective pitch diameter which is at least as great as the maximum allowable pitch diameter of the internal thread of the female member to be engaged therewith, such that upon engagement, the sizing thread turns will reshape said internal thread to a prescribed configuration having a pitch diameter determined by said sizing thread turns, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the Screw than said preparation portion, and said locking portion including at least one full thread turn, one flank of which bulges axially outward with the opposite flank being depressed, whereby upon engagement with said reshaped internal thread flank interference will be obtained along said bulging thread flank to lock the respective male and female members in assembled relation.

Claim 10

An externally threaded locking fastener member adapted to be engaged with an internally threaded female member, having an internal thread formation which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said fastener member including a driving head, a shank portion and a tapered work-entering end, with an external thread formed on at least a portion of said shank, said external thread including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of sizing thread turns of the radially relieved type and having a standard profile, said sizing thread turns having an effective pitch diameter which is at least as great as the maximum allowable pitch diameter of the internal thread of the female member to be engaged therewith, such that upon engagement, the sizing thread turns will reshape said internal thread to a prescribed configuration having a pitch diameter determined by said sizing thread turns, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the Screw than said preparation portion, and said locking portion including at least one full thread turn, one flank of which bulges axially outward with the opposite flank being depressed, whereby upon engagement with said reshaped internal thread flank interference will be obtained along said bulging thread flank to lock the respective male and female members in assembled relation.

Claim 11

An externally threaded male locking fastener for engagement with an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread permitted by said industry tolerances, such that upon engagement of the preparation portion with an internally threaded member, regardless of the tolerances encountered, said internal thread will be reshaped and sized to a desired, predicted uniform configuration having a pitch diameter determined by said preparation portion; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking thread portion includes a plurality of thread turns having a pitch diameter greater than the effective pitch diameter of the thread turns on said preparation portion, such that said locking thread portion will, upon engagement with said internal thread after reshaping thereof by said preparation portion, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 12

An externally threaded male locking fastener for engagement with an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread permitted by said industry tolerances, such that upon engagement of the preparation portion with an internally threaded member, regardless of the tolerances encountered, said internal thread will be reshaped and sized to a desired, predicted uniform configuration having a pitch diameter determined by said preparation portion; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking thread portion includes a plurality of thread turns having a pitch diameter greater than the effective pitch diameter of the thread turns on said preparation portion, such that said locking thread portion will, upon engagement with said internal thread after reshaping thereof by said preparation portion, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 13

An externally threaded male locking fastener for engagement with an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type said thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread permitted by said industry tolerances, such that upon engagement of the preparation portion with an internally threaded member, regardless of the tolerances encountered, said internal thread will be reshaped and sized to a desired, predicted uniform configuration having a pitch diameter determined by said preparation portion; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking thread portion including a plurality of thread turns having one flank thereof bulging axially in a first direction with the opposite flank of each said turn depressed inwardly in the same direction, such that said locking thread will, upon engagement with said internal thread after reshaping thereof by said preparation portion, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 14

An externally threaded male locking fastener for engagement with an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type said thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread permitted by said industry tolerances, such that upon engagement of the preparation portion with an internally threaded member, regardless of the tolerances encountered, said internal thread will be reshaped and sized to a desired, predicted uniform configuration having a pitch diameter determined by said preparation portion; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking thread portion including a plurality of thread turns having one flank thereof bulging axially in a first direction with the opposite flank of each said turn depressed inwardly in the same direction, such that said locking thread will, upon engagement with said internal thread after reshaping thereof by said preparation portion, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 15

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensionS held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of sizing thread turns of the radially relieved type, said sizing thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread, such that upon engagement, said sizing thread turns will reshape and size said internal thread, eliminating all variances due to tolerances and producing a thread form of predicted uniform configuration and pitch diameter, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking portion including at least one thread turn having a pitch diameter greater than the effective pitch diameter of said sizing thread turns, by a preselected valve, such that upon engagement of said reshaped internal thread with said locking thread turns, a predicted flank-to-flank interference will be obtained, which interference will maintain said male and female members in assembled relation.

Claim 16

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensionS held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of sizing thread turns of the radially relieved type, said sizing thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread, such that upon engagement, said sizing thread turns will reshape and size said internal thread, eliminating all variances due to tolerances and producing a thread form of predicted uniform configuration and pitch diameter, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking portion including at least one thread turn having a pitch diameter greater than the effective pitch diameter of said sizing thread turns, by a preselected valve, such that upon engagement of said reshaped internal thread with said locking thread turns, a predicted flank-to-flank interference will be obtained, which interference will maintain said male and female members in assembled relation.

Claim 17

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of sizing thread turns of the radially relieved type, said sizing thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread, such that upon engagement, said sizing thread turns will reshape and size said internal thread, eliminating all variances due to tolerances and producing a thread form of predicted uniform configuration and pitch diameter, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking portion including at least one full thread turn, one flank of which bulges axially outward with the opposite flank being depressed, whereby upon engagement with said reshaped internal thread flank, a prescribed degree of interference will be obtained along said bulging thread flank to lock the respective male and female members in assembled relation.

Claim 18

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of sizing thread turns of the radially relieved type, said sizing thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread, such that upon engagement, said sizing thread turns will reshape and size said internal thread, eliminating all variances due to tolerances and producing a thread form of predicted uniform configuration and pitch diameter, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking portion including at least one full thread turn, one flank of which bulges axially outward with the opposite flank being depressed, whereby upon engagement with said reshaped internal thread flank, a prescribed degree of interference will be obtained along said bulging thread flank to lock the respective male and female members in assembled relation.

Claim 19

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having one flank thereof bulging outwardly in a first axial direction with the opposite flank of said thread turns depressed inwardly in said first axial direction, whereby upon engagement of said preparation portion, with the internal thread of said female member, said internal thread will be reshaped to a desired, predicted configuration and provided with corresponding bulging and depressed flanks, deflected axially with regard to their initial configuratioN; and a locking thread portion position further from said work-entering end of the screw than said preparation portion, said locking portion including at least one locking thread turn having one flank thereof positioned to engage said reshaped, axially deflected bulging flank of said internal thread in interferring relation to produce a locking action.

Claim 20

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having one flank thereof bulging outwardly in a first axial direction with the opposite flank of said thread turns depressed inwardly in said first axial direction, whereby upon engagement of said preparation portion, with the internal thread of said female member, said internal thread will be reshaped to a desired, predicted configuration and provided with corresponding bulging and depressed flanks, deflected axially with regard to their initial configuratioN; and a locking thread portion position further from said work-entering end of the screw than said preparation portion, said locking portion including at least one locking thread turn having one flank thereof positioned to engage said reshaped, axially deflected bulging flank of said internal thread in interferring relation to produce a locking action.

Claim 21

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having one flank thereof bulging outwardly in a first axial direction with the opposite flank of said thread turns depressed inwardly in said first axial direction, whereby upon engagement of said preparation portion, with the internal thread of said female member, said internal thread will be reshaped to a desired, predicted configuration and provided with corresponding bulging and depressed flanks, deflected axially with regard to their initial configuration; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking portion including at least one locking thread turn having one flank thereof bulging outwardly in a second axial direction opposite to said first direction, with the oppositely disposed flank of said locking thread in turn being depressed, such that upon engagement of said locking thread turn with said previously reshaped internal thread flank-to-flank contact will be obtained between the bulging flank of said locking thread and that of said internal thread, respectively, producing flank-to-flank interference which maintains said male and female members in assembled relation.

Claim 22

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having one flank thereof bulging outwardly in a first axial direction with the opposite flank of said thread turns depressed inwardly in said first axial direction, whereby upon engagement of said preparation portion, with the internal thread of said female member, said internal thread will be reshaped to a desired, predicted configuration and provided with corresponding bulging and depressed flanks, deflected axially with regard to their initial configuration; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, said locking portion including at least one locking thread turn having one flank thereof bulging outwardly in a second axial direction opposite to said first direction, with the oppositely disposed flank of said locking thread in turn being depressed, such that upon engagement of said locking thread turn with said previously reshaped internal thread flank-to-flank contact will be obtained between the bulging flank of said locking thread and that of said internal thread, respectively, producing flank-to-flank interference which maintains said male and female members in assembled relation.

Claim 23

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said preparation portion including a plurality of sizing thread turns having a generally standard profile and an effective pitch diameter at least as great as the maximum allowable pitch diameter of said internal threads, with engagement of said sizing thread turns with said internal threads reshaping said internal threads to a predetermined uniform configuration having a prescribed pitch diameter, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, and having a thread form which will, upon engagement with said uniformly reshaped internal threads, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 24

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said preparation portion including a plurality of sizing thread turns having a generally standard profile and an effective pitch diameter at least as great as the maximum allowable pitch diameter of said internal threads, with engagement of said sizing thread turns with said internal threads reshaping said internal threads to a predetermined uniform configuration having a prescribed pitch diameter, regardless of the internal thread tolerances encountered; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, and having a thread form which will, upon engagement with said uniformly reshaped internal threads, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 25

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread permitted by said industry tolerances, such that upon engagement of the preparation portion with said internal thread, regardless of the tolerance encountered, said internal thread will be reshaped and sized to a desired, predicted uniform configuration, having a shape and pitch diameter determined by said preparation portion; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, and having a thread form which will, upon engagement with said internal thread after reshaping thereof by said preparation portion, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 26

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the radially relieved type, said thread turns having an effective pitch diameter that is at least as great as the maximum allowable pitch diameter of said internal thread permitted by said industry tolerances, such that upon engagement of the preparation portion with said internal thread, regardless of the tolerance encountered, said internal thread will be reshaped and sized to a desired, predicted uniform configuration, having a shape and pitch diameter determined by said preparation portion; and a locking thread portion positioned further from said work-entering end of the screw than said preparation portion, and having a thread form which will, upon engagement with said internal thread after reshaping thereof by said preparation portion, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 27

A combination as defined in claim 16, wherein said locking thread portion includes a plurality of thread turns having a pitch diameter greater than that of the thread turns on said preparation portion.

Claim 28

A combination as defined in claim 16, wherein said locking thread portion includes a plurality of thread turns having one flank thereof bulging axially in a first direction with the opposite flank of each said turn depressed inwardly in the same direction, such that upon engagement with said reshaped internal thread, said flank interference will be obtained along said bulging flanks.

Claim 29

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross-section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the raidally relieved type, said plurality of thread turns having one flank thereof bulging outwardly in a first axial direction with the opposite flank of said thread turns depressed inwardly in said first axial direction, such that upon engagement of said preparation portion with the internal thread of said female member, regardless of the industry tolerances employed, said internal threads will be reshaped and provided with a uniform thread form determined by said preparation portion, said uniform thread form having corresponding bulging and depressed flanks, deflected axially with regard to their initial configuration; and a locking thread portion positioned further from said work-entering end of the screw then said preparation portion, said locking portion including a plurality of thread turns having a thread form which will, upon engagement with said uniformly reshaped axially deflected bulging internal threads, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 30

In combination, an externally threaded male member and an internally threaded female member, said female member having an internal thread which is of a substantially circular cross-section and of generally uniform dimensions held within accepted, industry specified tolerances, said male member including a driving head, a shank portion, and a tapered work-entering end, with an external thread formation on at least a section of said shank, said external thread formation including, a preparation portion disposed adjacent said tapered work-entering end and including a plurality of thread turns of the raidally relieved type, said plurality of thread turns having one flank thereof bulging outwardly in a first axial direction with the opposite flank of said thread turns depressed inwardly in said first axial direction, such that upon engagement of said preparation portion with the internal thread of said female member, regardless of the industry tolerances employed, said internal threads will be reshaped and provided with a uniform thread form determined by said preparation portion, said uniform thread form having corresponding bulging and depressed flanks, deflected axially with regard to their initial configuration; and a locking thread portion positioned further from said work-entering end of the screw then said preparation portion, said locking portion including a plurality of thread turns having a thread form which will, upon engagement with said uniformly reshaped axially deflected bulging internal threads, produce a prescribed degree of interference along one or more of the engaged thread flanks, to lock said male and female members in assembled relation.

Claim 31

A combination as defined in claim 19 wherein said locking thread portion includes a plurality of thread turns having relatively straight flank surfaces, disposed to engage said bulging flanks formed on said internal thread by the preparation portion, said engagement producing the desired flank interference.

Claim 32

The combination as defined in claim 19 wherein said locking portion includes a plurality of locking thread turns having one flank thereof bulging outwardly in a second axial direction opposite to said first direction, with the oppositely disposed flank of said locking thread turn being depressed, such that upon Engagement of said locking thread turn with said previously reshaped internal thread, flank-to-flank contact will be obtained between the opposed engaged bulging flanks of said internal thread and said locking thread, respectively, producing the desired flank interference.