Damper stacks, rotor blades, and turbomachines are provided. A rotor blade includes a main body including a shank and an airfoil extending radially outwardly from the shank. The rotor blade further includes a platform surrounding the main body, the platform comprising a slash face. The rotor blade further includes a damper stack disposed at the slash face and extending generally along an axial direction. The damper stack includes a plurality of damper pins, each of the plurality of damper pins being in contact with a neighboring damper pin.