referring now to fig1 a fastener assembly 2 in accordance with the present invention is shown associated with a structural panel 4 and a sub - structure 6 . fastener assembly 2 includes a sleeve bolt 8 , a grommet assembly 10 and a receptacle assembly 12 . grommet assembly 10 is shown installed in an opening 5 in access panel 4 in its withdrawn position . as shown in greater detail in fig5 grommet assembly 10 includes a body 14 and a resilient circular retainer ring 16 . although not shown in fig1 grommet assembly 10 may also include a grommet cup 18 , as will hereinafter be discussed . in fig1 grommet body 14 is shown attached to access panel 4 by expanding the outer portion thereof to conform with a counterbore formed in surface 20 of the access panel 4 . receptacle assembly 12 includes a receptacle bracket or basket 22 , a barrel 24 and an externally threaded stud 26 . tabs 28 on barrel 24 mate with a pair of slots 30 formed in base of stud 26 and are deflected inwardly to engage the stud and connect the barrel thereto . as shown in fig5 barrel 24 also includes tabs 32 which are inserted in a pair of slots 34 formed in basket 22 , thereby connecting the barrel to the basket . slots 34 are circumferentially greater in length than the width of the tabs 32 thereby permitting the barrel and stud to rotate to a limited degree with respect to basket 22 . basket 22 is secured to sub - structure 6 by any suitable means , such as by rivets 31 . it should be understood that while receptacle assembly 12 and basket 22 have been illustrated and described as an assembly of individual elements , they could comprise a single element without departing from the spirit and scope of the invention . the internally threaded sleeve bolt 8 is shown in fig1 in its disengaged and withdrawn position with respect to panel 4 . sleeve bolt 8 is shown secured by retainer ring 16 engaging a groove 36 formed in the sleeve bolt . as can readily be seen , by pushing sleeve bolt 8 toward stud 26 , the split retainer ring 16 will expand over the outer surface 37 of sleeve bolt 8 permitting axial movement of the sleeve bolt toward the stud . rotation of sleeve bolt 8 will cause it to threadably engage stud 26 of receptacle assembly 12 . in the preferred embodiment of the invention , sleeve bolt 8 and stud 26 have double lead threads in order to decrease the time and motion required to remove and reinstall the panel . barrel 24 may include inwardly facing protrusions 38 which frictionally engage the exterior surface 37 of sleeve bolt 8 when it is threadably engaged on stud 26 , thereby securely locking the sleeve bolt to receptacle assembly 12 when panel 4 is secured to sub - structure 6 . in the preferred embodiment , protrusions 38 are produced by forcibly deforming the outside of barrel 24 by applying pressure thereto . it should be understood that any suitable friction lock between the internal surface of barrel 24 and the external surface 37 of sleeve bolt 8 would suffice . another example of such a friction lock is a plastic insert installed through the side of barrel 24 . grommet assembly 10 , panel 4 and sub - structure 6 illustrated in fig1 are shown in greater detail in fig2 . as previously indicated , grommet assembly 10 includes grommet body 14 and split retainer ring 16 . grommet body 14 may fit flush against the inner surface of panel 4 . however , in some instances , the thickness of panel 4 and sealing requirements may ncessitate the use of a gasket 40 between the panel 4 and sub - structure 6 . in this embodiment of the invention , ring 16 and sleeve bolt 8 each secure the other to panel 4 . as can better be seen in fig2 with the absence of sleeve bolt 8 , no structure is provided to secure retainer ring 16 to grommet assembly 10 . referring now to fig3 and 4 , as well as fig5 a grommet cup 18 may be provided to secure ring 16 to grommet body 14 . in fig3 a partial recess has been formed in inner surface 21 of panel 4 to receive a portion of grommet assembly 10 . in fig4 a recess of sufficient depth has been formed in surface 21 to permit the grommet assembly to fit flush with the inner surface of panel 4 . this embodiment is applicable to those situations wherein the thickness of panel 4 permits the use of a countersink and the sealing requirements do not necessitate use of a gasket . reference will now be made to fig6 where an enlarged view of a portion of grommet assembly 10 is shown . retainer ring 16 is shown positioned within grommet body 14 and secured thereto by cup 18 . retainer ring 16 fits within a cavity 50 formed by body 14 and cup 18 . surface 52 of the grommet body 14 forms the upper portion of cavity 50 , and is inclined upwardly and outwardly from the nominal plane of the cavity 50 . the angle of surface 52 with respect to a plane which is perpendicular to the centerline of body 14 is shown as &# 34 ; x &# 34 ;. retainer ring 16 , as previously described is a circular split ring which provides circumferential resilience . retainer ring 16 has upper and lower annular grooves 54 adjacent its inner periphery . grooves 54 form upper and lower surfaces 56 which are at an angle &# 34 ; y &# 34 ; with respect to the plane of ring 16 . it is important to note that surfaces 56 form sharp edges 58 with the radially innermost surface 60 of ring 16 . as will hereinafter be discussed , edges 58 and angle y are important to the present invention . in an alternate embodiment of the invention ( not shown ), top groove 54 and its attendant sharp edge 58 are eliminated from the top of retainer ring 16 . this is done to enable retainer ring 16 to be manufactured so as to have minimum thickness , a requirement for some applications . as long as groove 54 and its attendant sharp edge 58 are on the lower surface , or sub - structure side of the retainer ring , the advantage of the groove is not lost . however , both grooves are generally desired so that the possibility of installing the retainer ring upside down is eliminated as shown in fig7 annular groove 36 in sleeve bolt 8 has a lower surface 62 which forms an angle &# 34 ; z &# 34 ; with respect to a plane perpendicular to the axis of the sleeve bolt . the angles just identified x , y , and z result in the present invention being extremely effective in retaining sleeve bolt 8 in the grommet assembly 10 and hence , in panel 4 when the sleeve bolt is disengaged . in the devices of the prior art these angles have essentially been equal to zero degrees , as previously defined herein . this has resulted in a couple being created , on occasion , when sleeve bolt 8 is forcibly angularly displaced from its perpendicular orientation with respect to the panel surface in its fully withdrawn position , while being secured by ring 16 positioned within groove 36 . the couple , or moment , is created when the prior art geometry causes the split ring to be forced between surface 62 of sleeve bolt 8 and surface 52 of the grommet body , thus forcing resilient ring 16 to expand over surface 92 , and permitting sleeve bolt 8 to become disengaged from grommet assembly 10 and panel 4 . this action directly results in loss of bolt 8 and the attendant problems previously described . it has been discovered that the incidence of sleeve bolt disengagement from grommet assembly 10 can be significantly reduced by causing angle x to be within the range of three ( 3 ) to eight ( 8 ) degrees and substantially five ( 5 ) degrees in the preferred embodiment . of somewhat lesser , but still significant importance is angle z formed by surface 62 of sleeve bolt 8 . angle z should also be within the range of three ( 3 ) to eight ( 8 ) degrees in the preferred embodiment for optimum effectiveness , and preferrably five ( 5 ) degrees . angle y formed by surfaces 56 on ring 16 should be within the range of seven ( 7 ) to fifteen ( 15 ) degrees and is fifteen ( 15 ) degrees in the preferred embodiment . the effect of the preferred angular relationships just described is to reduce the moment or couple on ring 16 when the sleeve bolt is forcibly angularly displaced while retainer ring 16 is positioned within groove 36 of sleeve bolt 8 . the reduction of the moment which would otherwise be present results in the ring not being expanded , thereby substantially reducing , if not eliminating the disengagement of sleeve bolt 8 from grommet assembly 10 and panel 4 . an alternate embodiment of receptacle assembly 12 is shown in fig8 . receptacle assembly 12 &# 39 ; in fig8 is similar to that shown in fig5 except that a washer 64 is positioned between basket 22 &# 39 ; and barrel 24 &# 39 ;. barrel 24 &# 39 ; includes tabs 32 &# 39 ; and washer 64 includes tabs 65 extending radially outwardly , similar to tabs 32 on barrel 24 in fig5 . tabs 32 &# 39 ; and 65 are received by slots 34 &# 39 ; in basket 22 &# 39 ;. washer 64 and barrel 24 &# 39 ; have mating curved surfaces which permit relative movement therebetween . this permits stud 26 &# 39 ;, which is attached to barrel 24 &# 39 ; by means of tabs 28 &# 39 ; engaging a pair of slots 30 &# 39 ; in the base of stud 26 &# 39 ;, to angularly deflect , thereby aiding in the engagement of sleeve bolt 8 thereto . this is particularly advantageous when sub - structure 6 has significantly deflected from the original hole pattern in panel 4 . while the fastener assembly of the present invention has been described with reference to several preferred embodiments , it is to be understood that various changes and modifications may be made within the scope and spirit of the invention , and the claims which are appended hereto are intended to define the scope of the invention .