tropical36 wrote:
This so intrigued me, that I did some further research and found this, so I would like to hear more on how this could have possibly happened and maybe some others have had a similar experience.
"Since the tubes in a receiver fit tightly, there is only a shear load on the pin, with Very minimal (neglectable) bending load. If the jaws on the female part of the wagon hitch are 3" apart, and the receiver hitch is 1" thick, there is 2" of bending moment (or leverage) on the hitch pin. A pin or bolt will handle a ridiculous amount in a "shear only" setting. Especially "dual shear" where the load effectively has to shear the pin in 2 places for a failure (such as the receiver tube).
For example : a 5/8 pin: (.3125)^2 X 3.14= .30662 in^2 area of pin. If the steel is 75KSI material (1045 cold drawn), then each shear instance will theoretically handle 23000 pounds of shear load. Since the load is being spread over 2 instances (dual shear) it should hold 46,000 pounds before shearing. This all depends on the alloy of the steel being used in the pin of course. Hard to put 46K of direct drawbar load on a pickup. Not saying impossible, but hard to do."
After reading your post, makes me wonder if the tubes were not fully extended, which would allow it to get a running start.
