The most common style of mandrel linkage, originally developed in the late 1950’s to reduce pitch and permit universal flexure of the mandrel balls. A significant improvement over brute links, which see. H-type links come in two major varieties, poppet and split. The original H-type link was of the split variety because of limitations in machining and metallurgical technologies at the time of its development.
The poppet style has the advantages of being a single piece and therefore can carry a heavier load and less expensive to produce.