Roller Chain - "Pre-loading" or "Pre-stretching"

What is meant by "pre-loading or pre-stretching" roller chain, why is it done, and is it important?

Answer: Following assembly, an initial load is applied to the roller chain, which is called pre-load. This loading approximates the recommended maximum loading in service and is done to align the various roller chain components such as pins, bushings, and link plates. The benefit of pre-loading is that it helps greatly eliminate the initial elongation often found in "lesser" roller chains. Elimination of this initial elongation can increase the roller chains useable service life therefore pre-loading is very important. GiDi Industrial Chain Factory pre-loads every standard and heavy series roller chain it manufacturers.