A unit locking a ring sector attachment device onto an aircraft turbomachine casing, the unit including two clamping arms connected to each other at their aft ends by a connecting arm extending approximately parallel to the general direction between the two clamping arms. The unit also includes a passage enabling gripping of the unit on each side of a fictitious median plane orthogonal to the circumferential direction, each passage being formed in the connecting arm, extending along a direction line approximately parallel to the direction between the arms.