A locking spacer assembly configured to fill a final spacer slot in a disk groove between platforms of adjacent blades of a blade assembly comprising: a first side piece comprising a top surface, an inner surface and an outer surface; a second side piece comprising a top surface, an inner surface and an outer surface; a bolt configured to be inserted between the inner surface of the first side piece and the inner surface of the second side piece; and a mid piece configured to be disposed onto the bolt and inserted between the inner surface of the first side piece and the inner surface of the second side piece, wherein the top surface of the first side piece comprises a L-shape formed by a tab and a recess, wherein the top surface of the second side piece comprises a L-shape formed by a tab and a recess, wherein the mid piece comprises a hollow cylindrical body to receive the bolt, wherein the mid piece comprises a top platform disposed around a top of the hollow cylindrical body and a middle platform disposed around a bottom of the hollow cylindrical body, wherein the top platform comprises two L-shaped axial side surfaces adapted to flush with the L-shaped top surface of the first side piece and the L-shaped top surface of the second side piece, wherein the first side piece comprises an aperture disposed through the tab of the first side piece, wherein the second side piece comprises an aperture disposed through the tab of the second side piece, and wherein a first pin and a second pin are radially disposed through the aperture of the first side piece and the aperture of the second side piece extending toward to the middle platform of the mid piece. a first side piece comprising a top surface, an inner surface and an outer surface; a second side piece comprising a top surface, an inner surface and an outer surface; a bolt configured to be inserted between the inner surface of the first side piece and the inner surface of the second side piece; and a mid piece configured to be disposed onto the bolt and inserted between the inner surface of the first side piece and the inner surface of the second side piece, wherein the top surface of the first side piece comprises a L-shape formed by a tab and a recess, wherein the top surface of the second side piece comprises a L-shape formed by a tab and a recess, wherein the mid piece comprises a hollow cylindrical body to receive the bolt, wherein the mid piece comprises a top platform disposed around a top of the hollow cylindrical body and a middle platform disposed around a bottom of the hollow cylindrical body, wherein the top platform comprises two L-shaped axial side surfaces adapted to flush with the L-shaped top surface of the first side piece and the L-shaped top surface of the second side piece, wherein the first side piece comprises an aperture disposed through the tab of the first side piece, wherein the second side piece comprises an aperture disposed through the tab of the second side piece, and wherein a first pin and a second pin are radially disposed through the aperture of the first side piece and the aperture of the second side piece extending toward to the middle platform of the mid piece.