Abstract: A prevailing torque fastener has a portion of the internal thread deformed from a circular cross-section to an approximately elliptical cross-section by a pair of die impressions on diametrically opposed sides of the exterior of the body. Each die impression is skewed from a plane normal to the axis of the fastener at an angle corresponding to the lead of the thread. Each die impression is made with a jaw having a central circular arc with a radius greater than the radius of the undeformed fastener. The opening between the jaws has a perimeter equal to the circumference of the undeformed fastener. Each edge of the die impression is at a predetermined elevation relative to the thread profile, preferably aligned with the crest of the thread. The location of the die impression is controlled by threading the fastener against a stop and crimping the fastener between jaws spaced a known distance from the stop.

Abstract: A prevailing torque fastener has a portion of the internal thread deformed from a circular cross-section to an approximately elliptical cross-section by a pair of die impressions on diametrically opposed sides of the exterior of the body. Each die impression is skewed from a plane normal to the axis of the fastener at an angle corresponding to the lead of the thread. Each die impression is made with a jaw having a central circular arc with a radius greater than the radius of the undeformed fastener. The opening between the jaws has a perimeter equal to the circumference of the undeformed fastener. Each edge of the die impression is at a predetermined elevation relative to the thread profile, preferably aligned with the crest of the thread. The location of the die impression is controlled by threading the fastener against a stop and crimping the fastener between jaws spaced a known distance from the stop.

Abstract: An aerospace fastener comprises a blot with a roll-formed thread, and a nut with a similar thread having a uniform pitch P. The bolt has a cylindrical shank, a threaded tip and a run-out zone between the shank and tip. The thread root in the run-out follows a smooth S-shaped curve with the concave portion preferably having a radius in the range of from 2P to 2.7P. The run-out extends from 1.4P to 2.3P from the maximum grip plane of the bolt, and preferably extends from 1.6P to 2P from the maximum grip plane. The root of the thread in the run-out lies within an envelope defined by boundaries which take into account the maximum and minimum material conditions of the bolt. The nut has a run-in truncating the crest of the nut thread complementary to the run-out to clear the root of the bolt thread when the nut is assembled on the bolt in the minimum grip condition.

Abstract: An aerospace fastener comprises a bolt with a roll-formed thread, and a nut with a similar thread having a uniform pitch P. The bolt has a cylindrical shank, a threaded tip and a run-out zone between the shank and tip. The thread root in the run-out follows a concave curve having a radius in the range of from 2.0P to 2.7P and extends 1.58P to 1.8P from the maximum grip plane of the bolt. The nut has a convexly curved run-in truncating the crest of the nut thread complementary to the run-out to clear the root of the bolt thread when the nut is assembled on the bolt in the minimum grip condition. This permits the nut to be assembled on the bolt further than in a conventional combination, and shortening of the nut and bolt by at least 1P to save weight.

Abstract: An aerospace fastener comprises a bolt with a roll formed thread, and a nut with a similar thread having a uniform pitch P. The bolt has a cylindrical shank, a threaded tip and a run-out zone between the shank and tip. In the run-out, which is no longer than 2P, and in preferred embodiments is in the range of from 1.6P to 1.9P, the root of the roll formed bolt thread increases diameter continuously from the minor diameter of the tip thread to the diameter of the shank. The nut has a conical run-in truncating the crest of the nut thread parallel to the run-out to clear the root of the bolt thread when the nut is assembled on the bolt in the minimum grip condition. This permits the nut to be assembled on the bolt further than in a conventional combination, and shortening of the nut and bolt to save weight. Preferably the crest of the bolt thread is at the major diameter of the tip thread at distances beyond 0.75P from the maximum grip plane of the bolt.

Abstract: A male threaded fastener has a plurality of impressions on the nonload-bearing flank of the thread that receives material swaged from a collar to lock the collar and pin together and increase the breakaway torque of the collar. The impressions have a depth of about 0.1 to about 0.3 of the depth of the thread from root to crest. The thread is free of impressions at least 1.5 pitch lengths from its ends.

Abstract: A swagable collar has longitudinally extending internal ribs in its bore that when the collar is swaged over a threaded pin dam a potential leak path between the thread flanks and along the root of the thread and increase the lock between the collar and the pin. The ribs extend at least two thread pitch lengths.

Abstract: This invention provides a fastener having a shank with a relatively abrupt transition from an unthreaded portion to a full thread dimension, the thread runout occupying no more than one pitch length of the thread in the axial dimension, and circumferentially extending no more than about one-fourth of the circumference of the thread at its pitch diameter. The counterbore of the nut is reduced in length in light of the short transition section of the shank. The threads are rolled on the shank by opposed dies having ridges complementary to the thread to be produced which run out at one edge of the die with spaced, generally symmetrical end walls which are relatively short axially of the ridges so that the full thread dimension is achieved abruptly.

Abstract: An improved device for the stamping of identification or other insignia on work pieces as part of the operations performed thereon in rotating machines such as lathes, automatic lathes, screw machines or the like. The stamping device is carried on a tool slide of the machine for movement toward and away from the work piece and includes a stamp having a flat face containing raised characters intended to be imprinted in the work piece, means to move the stamp to an extreme outer position when the slide is withdrawn from the work piece and to latch the stamp in said outer position, and means responsive to contact of the stamp assembly with the rotating work piece as the slide is moved toward the work piece to release the latch means.