An apparatus includes a handle portion, an end effector, an anvil, a knob, and a monolithic closure rod. The monolithic closure rod includes a proximal shank portion, a distal trocar portion, and a band portion. The proximal shank portion is located within the handle portion and is configured to linearly actuate in response to rotation of the knob. The distal trocar portion is configured to selectively couple with the anvil in order to actuate the anvil relative to the end effector. The band portion extends between the proximal shank portion and the distal trocar portion and provides a reduced cross-sectional area. The monolithic closure rod consists of a single homogenous continuum of material extending along the lengths of the proximal shank portion, the band portion, and the distal trocar portion.