Posted By Frank Hallett I'm sure that there are people who are far more technically qualified to discuss this topic, but none seems to have seen your question. As I understand it, the basic definition of a "short" link is one that is only a given percentage longer than the lateral measurement. A "Long" link is one that exceeds the "short" link dimensions. No, I don't know what the actual proportions are! However, the reason for banning "long" links is quite simple; they have the ability to fold across one another and lock in place when lifting. This will either lead to a sudden release when the links unfold or, even worse, a catastrophic collapse as the chain parts because of the stresses imposed on the folded links. I'll now stand back and watch an experts opinion roll in. Regards Frank Hallett