An integrated casing spacer and joint restraint unit is attached to each of a pair of pipe sections adjacent to an end-to-end connection of the pipe sections by means of first and second spacerretainer ring members. The cone has a plurality of milled teeth at selected locations on the cone. Furthermore, an average crystal grain diameter of the TiAl alloy is 500 m or less, and variation in crystal grain diameter in the entire target is limited within 30%.