3 legged spider clamps (6″) from Inspection Arsenal can hold round parts from 1.18″ to 6″ in diameter.
More options for inspections with the legs plucked off the 3-legged Spider Vise™. The leg comes with o-rings and adjustable pins to provide grip on parts in position for inspection. Vises are made of black anodized aluminum seated on a 3/4″ x 2″ steel stand-off that is able to be secured by flat-head screws. Height can be incremented with the use of additional taller stand-offs. M6 and 1/4-20 mounting thread.