High temperature flange joint, exhaust diffuser and method for coupling two components in a gas turbine engine

A high temperature flange joint in a gas turbine engine includes a first flange formed on a first component abutting a second flange formed on a second component. The flange joint includes multiple adjacently spaced bolt connections. Each bolt connection includes a first spacer plate bearing against the first flange and a second spacer plate bearing against the second flange. First and second lock washers are provided that bear against the first and second spacer plates respectively. A bolt is inserted through the first and second flanges, the first and second spacer plates and the first and second lock washers. The bolt is preloaded to clamp the first flange to the second flange. Each spacer plate has a respective thickness and is sized to enhance a bearing surface in contact with the respective flange. Thereby, a bolt preload is maintained during operation of the gas turbine engine.