A surgical instrument includes a shell having a housing and a shaft. The shell including first and second shell components configured to engage one another to form the shell, each of which is monolithically formed to include a housing portion and a shaft portion. Upon engagement of the first and second shell components with one another, the housing portions cooperate to form the housing of the shell while the shaft portions cooperate to form the shaft of the shell. An end effector assembly is operably coupled to the shaft at a distal end of the shaft. A handle assembly is operably coupled to the housing. A drive assembly disposed within the shell is operably coupled between the handle assembly and the end effector assembly such that actuation of the handle assembly manipulates the end effector assembly.