what is generally the largest single octopus hook size to comply with the 5/8 inch rule?

I measured a Gamakatsu 3/0 octopus hook and its gap width is just under 5/8ths inch, thus can be used for salmon and steelhead fishing. A 4/0 would have a gap that is greater than 5/8ths inch. The measurements listed here are specific to Gamakatsu octopus hooks. A different brand or different style of hook is likely to have a different gap width than the Gamakatsu 3/0 octopus. If not sure, anglers should carefully measure the width of the gap to make sure it does not exceed 5/8ths inch.