High temperature low thermal expansion fastener

A fastener which can be used in a high temperature environment for joining at least two elements of selected thickness which each have a common aligned hole, comprising:

• (a) a pin, which includes a head of greater cross-sectional dimension than the aligned holes, and a shank which adjoins the head, the shank including a distal portion with smaller cross-sectional dimension than the head and an inset portion located between the head and distal portion and which has a smaller cross-sectional dimension than the distal portion such that a head-facing shoulder is formed near where the distal portion adjoins the inset portion;
• (b) at least one shell insert, each including an inner surface which is seatable in the inset portion;
• a distal-facing surface;
• and an outer surface which is threaded and which has a radius of curvature at least equal to a radius of curvature of the distal portion, said shell inserts being positionable around the inset portion of the shank so that their distal-facing surfaces can be placed in abutting relationship with the head-facing shoulder on the pin;
• and
• (c) an internally threaded member of selected axial thickness which can be screwed onto the threaded outer surface of said shell inserts to maintain the inserts in abutting relationship with the inset portion.