Just to put it to bed so to speak......
These will be strong enough to hold a (modest) weight in a hammock. They are not like the alloy ones that bend under load!
They would not take a directly loaded force but for a gradual strain they would be ok, as for climbing you would need something a lot more substantial to take the extra force of a direct pull (usually also equipped with a screw lock gate)
So in summary...
Would i use one (well2) for a hammock? Yes (but prob not if i was 18stone)
Would i use it as a towing link? No
Would i Climb it? No
Kit Suspend or leash? Yes