Fastener with torque indication - has abutments on ends of pin in through-bore of stop prevented from rotation under predetermined tension

摘要

The fastener has a male screw thread (12) and an opening (11) extending through the fastening parallel to an axis of the thread. An elongate element (15) protrudes from opposite ends of the opening with abutments (16,17) between which the fastener is trapped. When the fastener is unstressed, at least one of the abutments is free to turn about the axis. When the fastener is subjected to a predetermined tensile stress, the fastener is stretched to engage both abutments under pressure and impede turning of one of the abutments relative to the fastener. One of the abutments can be formed separately from the elongate element and is prevented from moving relative to the element along the axis. One or each of the abutments can be annular.