Abstract: A lock spindle blind fastener to be set with a single action tool where the fastener includes a pin or mandrel, a sleeve and a locking collar; the sleeve has an enlarged head which has a straight counterbore for the initial reception and guiding of the locking collar with the counterbore communicating with a bore portion having an entrant resistance angle for reception of the collar during setting. The entrant resistance angle is selected to be of a magnitude to provide hold-off of the locking collar. The strength of the mandrel and other characteristics of fastener components are related to the force required to deform the locking collar along the entrant resistance angle such that a high strength blind fastener is provided which can be set by a single action tool.

Abstract: An improved pull-type blind fastener is disclosed comprising a tubular sleeve having a mandrel longitudinally movable within the sleeve for forming a head on one end thereof and a locking collar adapted to be moved into engagement with a lock pocket provided on the mandrel as the fastener is set whereby the mandrel is locked within the sleeve. The locking collar is generally cylindrical in shape having a bore extending therethrough which bore is defined by an inner portion of a first predetermined diameter and an outer portion of a diameter greater than the first predetermined diameter. The enlarged diameter outer portion operates to provide a relieved area at the outer end of the locking collar and immediately adjacent the nose assembly of an installation tool so as to prevent flow or wiping of collar material axially outwardly between the mandrel and the nose assembly of the installation tool during setting of the fastener.

Abstract: A lock spindle blind fastener, formed of a suitable, related metal, which includes a mandrel, a sleeve and a locking collar in which the sleeve has a countersunk head having an under head included angle greater than the included angle of the as-prepared hole and in which the sleeve head has a straight counterbore for the initial reception of the locking collar, communicating with an entrant resistance angle for reception of the collar during setting. Such entrant resistance angle is less than the under head angle. The relationship of these angles is such as to permit the use of a single action, or non-shifting head, setting tool. Also, such angular relationship assures an effective lock between the mandrel, or spindle, and the sleeve when the fastener has been set.