An aircraft brake rotor (60) or stator (110) includes a circular disk having first and second walls (62, 112) and a peripheral wall (64, 114) including at least one notch (66, 116) having a bottom (70) and first and second sides (72). The disk further includes first and second peripheral wall portions separated by the notch (66, 116). An insert (10) is mounted in the notch (66, 116) and has first and second legs (14) with inner and outer walls (20, 22) extending along the notch first and second sides (72). The insert (10) has a first portion having a first width. A circumferential distance between the notch first wall (72) and the notch second wall (72) at a position toward the peripheral wall having the notch (66, 116) has a width less than the insert first portion first width. A retainer (30, 118) overlies the disk first and second walls (62, 112) and a portion of the insert (10) to limit axial movement of the insert (10) relative to the rotor (60) or stator (110) disk.