If my goggling is correct a Kn is 220 lb, so 31 Kn=6820 lb. If cost is an issue those things will work. You have to make sure that you screw the thing closed really well though. I'm no expert, but I think the biners are rated for a dynamic load vs the static load on these links. Don't know that it makes a difference for our application since there are much weaker links in the system that will fail first. Personally I like using a soft shackle, much lighter and I can make them my self.
Last edited by Mouseskowitz; 01-07-2013 at 21:05..
Reason: Should proof read before posting...