Perhaps they didn't perform to spec. Both were using grab hooks but only one if the 3 failures was at a hook point. No sharp edges. It was hooked to a clevis.
With the Kubota pull, I have no doubt that I was pulling near 10k drawbar pull. Everything was perfect for traction. Short chain, raised hitch, and maybe a 10 degree downhill in the woods with good footing. It was a gr70, bit in all fairness, it was a 10+ year old chain that has pulled a lot.
The pulls with the BH and 3/8, I think I exceeded the 26k or so rating. We are talking an 18k machine with lits of weight over the pulling tires. No intentional jerk on my part but that dont mean the chain felt some when the tires start spinning and kinda do that little hop thing they do while trying to bite. Certainly not like getting a running start. And kinda like slow motion being in 1st gear, if you can kinda get a visual of what I am saying.
So I think I can attribute the 5/16 breaking due to optimum conditions +old chain. And the 3/8 broke cause it was just too small for a big ole hoe.
Either way, I don't rely on 5/16 if I know I am going to be pulling hard. 3/8 is no big deal for me. And next time I buy some chain, I think I will step up and get some 1/2 for the BH.
Also worth noting that the chain is only tested to 2x wll. And only random same are treated for break strength. So you are really only gaurenteed 2x wll.
