A shaft for a cabin air compressor includes a first attachment portion, a second attachment portion, an intermediate portion, a retention flange, and a tie rod support pocket. The first attachment portion is disposed at a first end of the shaft. The second attachment portion is disposed at a second end of the shaft opposite the first end. The intermediate portion extends from the first attachment portion to the second attachment portion and an interior wall of the intermediate portion defines an inner shaft space. The retention flange extends a first distance into the inner shaft space from the interior wall of the intermediate portion and is offset from the first attachment portion by a second distance. The tie rod support pocket is defined by the interior wall, extends between the flange and the first attachment portion, and is configured to receive a tie rod support.