Or maybe like this? (has latch)
Couple of notes:
1) In boating, we have not had good luck with shackles and the like made in China. I favor those made in the USA and tested, such as the ones made by Crosby company. Also consider that these may be heavily shock loaded when/if something does happen. Also, all the force may be on one hook alone.
2) Edit: I'm not too familiar with sling hooks, so I checked the Crosby Group's always-excellent catalog for information. There is no specific percentage of strength rating to subtract for angled pulls, like there is with a shackle, however they do specify that the load should make a straight pull on the hook. I think this has more to do with making sure the load cannot fall
on the latch instead of the hook. So as long as you can be sure the load stays on the hook, it seems like you retain full capacity. Here were the pertinent notes:
a) When placing two (2) sling legs in hook, make sure the
angle between the legs is less than 90° and if the hook or
load is tilted, nothing bears against the bottom of this latch.
(See Figure 3 & 4.)
b)Latches are intended to retain loose sling or devices under
c) Latches are not intended to be an anti-fouling device.
Sorry if this is more than anyone ever wanted to know about sling hooks,
Actually, after doing the small bit of research to answer my own question on sling hooks, I've decided that I really need to put a bit more thought into my own safety chain system, and check things over to make sure that everything is rated adequately and that I don't have any "weak links." I have some locking S-hooks but will have to check them over for a rating. Meanwhile, I think I'll use the "link" style ones again.
Thanks, Roger, for bringing this up - safety chains are probably one of those slightly "forgotten" areas in trailering (not being as 'fun' as mods and such).
One thing is that the typical "S" hooks have always made me a bit nervous. How is one supposed to have faith that they will remain in the "hook" position if something goes awry?