What is the difference between pitch diameter and the diameter of the roller chain called?

The difference between the pitch diameter and the diameter of the roller chain is referred to as the bottom diameter. In the context of roller chains, the pitch diameter is the diameter of an imaginary circle that runs through the centers of the chain pins. This is crucial for ensuring that the chain properly aligns with the sprockets it engages with.

The bottom diameter, on the other hand, is associated with the roller’s profile and represents the diameter at the base of the roller. Understanding this difference is essential for designing and analyzing roller chain systems, as it impacts the overall performance, load distribution, and compatibility with sprockets.

Citing the other options, the top land typically refers to a feature in gear teeth design, addendum pertains to the radial distance from the pitch circle to the top of the teeth in gears, and inside diameter would refer to the diameter of a hollow cylindrical object, which is not applicable in this context. Each of these terms describes different aspects of mechanical elements but does not accurately describe the specific difference between pitch diameter and the diameter of a roller chain.