piston rod

a rod communicating the rectilinear motion of a piston to the small end of a connecting rod or elsewhere.

Origin of piston rod

First recorded in 1780–90

An adaptation on the top of the piston-rod, stretching out athwart the cylinder, from the ends of which the side-rods hang.

The Sailor's Word-Book |William Henry Smyth
To attach something to the piston-rod to be moved by it, was a simple matter—crank and wheel.

What Is Man? And Other Stories |Mark Twain (Samuel Clemens)
In practice, a piston-rod or other reciprocating part may be attached to any point on the circumference of the smaller wheel.

The New Gresham Encyclopedia |Various
In the centre of the room, lightly brandishing the piston-rod of a steam-engine, stood Guy Heavystone alone.

The Luck of Roaring Camp and Other Tales |Bret Harte

This is generally done by causing the piston-rod to work between guides, and a jointed arm connects it with the crank.

Great Facts |Frederick C. Bakewell

piston rod

the rod that connects the piston of a reciprocating steam engine to the crosshead

a less common name for a connecting rod