Abstract: An apparatus for tightening a threaded fastener of the kind having: a shank with an axial bore; a gauge pin positioned in the bore and connected to the shank, a part of the gauge pin either protruding from, flush with, or recessed from an end face of the fastener; and an indicating member rotatably supported on the either protruding from, flush with, or recessed from part of the gauge pin, the indicating member being arranged such that it is free to rotate when the fastener is unstressed but when the fastener is subjected to a predetermined tensile load the indicating member is held against rotation, wherein the fastener has either a head connected to an end of the shank adjacent the indicating member or, alternatively, has a nut which is threadedly engageable with an end of the shank adjacent the indicating member; the apparatus including: a receiving member, rotatably supported in the apparatus, for receiving the head connected to or for receiving a nut engageable with the shank; a device for effecting rota

Abstract: A hollow bolt (10) contains first and second electrical contact elements (13, 16) which are moved apart when the bolt is subjected to a predetermined tensile lead. A carrier (14) for a first of the contact elements contains an inductor (18) connected electrically between the contact elements, the condition of the contact elements is ascertained by inductive coupling of test apparatus with the inductor.

Abstract: For indicating when the tension in a bolt reaches a predetermined value, there is provided an electrical contact (24) which is held in a position adjacent to an axially facing surface (20) of the bolt and in a fixed position relative to a remote part of the bolt. Tightening of the bolt reduces the clearance between the contact and the surface of the bolt. When the clearance is eliminated, a bulb (27) is illuminated.

Abstract: A load indicating fastener such as a bolt (10) or stud, has a shank (12) which is subject to tensile loading in use. The shank (12) has an axially extending bore (22) which receives a first gauge pin (30) anchored at its inner end (32) to the shank (12) and protruding outwards beyond an end face (16) of the fastener. An indicating member (40) is rotatable on the protruding portion of the gauge pin (30) between the end face (16) of the fastener and the head (34) of the pin (30), so that the indicating member (40) is free to rotate when the shank (12) of the fastener is unstressed but when the shank (12) is subject to a predetermined tensile loading is held against rotation by contact with the end face (16) of the fastener. A second gauge pin (42) is received within an axially extending bore (36) in the first gauge pin (30) and is anchored at is inner end and protrudes outwards beyond the outer end of the first gauge pin (30).

Abstract: A load-indicating fastener, such as a bolt (10), has a bore (18) which extends from an end face (16) of the bolt and which can receive a gauge pin (30). The gauge pin (30) is free to rotate so that it can be withdrawn completely from the bolt. In use of the bolt, the gauge pin (30) is reinserted into the bore (18) and screwed down until the end of the pin engages the inner end of the bore. As the bolt is tightened, causing elongation of the shank (12) of the bolt (10) and therefore of the bore (18), the user can check the loading on the bolt by periodically rotating the gauge pin (30), to maintain contact between the end of the pin and the inner end of the bore, until the pointer (40) reaches the mark (28) on the end face (16) of the bolt, indicating that the predetermined loading has been reached.

Abstract: An elongate pin extends in an axial bore in a threaded fastener, at least one end portion of the pin protruding from the bore. An abutment is provided on said one end portion, while when the fastener is in an unstressed condition may rotate about the longitudinal axis thereof. Conversely, when the fastener is subjected to a predetermined tension, rotation of the abutment is prevented by engagement with an end face of the fastener.