ORIGINAL: GR8atta2d
However, sometimes, a metal can fail
Well metal just doesn't fail. In this case I'm assuming it's probably T6 6061 Aluminum,if it's 6005 thats another issue and the wrong alloy for this application (it also could be a 7000 series but due to cost I'm betting not). If it broke there can be a couple reasons for this. The main one being the fact that it didn't make properties. In the case of 6061 T6 it should have an ultimate strength of 38000 PSI and a yield strength of 35000 PSI with 10% elongation. the Brinell hardness is 95 minimum. It has a shear strength of 35000 PSI. Consequently metal does not just fail out of the blue, no Bow is putting out that force.
AsI said the reasons fornot making propertiescan be many. I hope anyone using Aluminum in such an application demands,Tensile tests on every lot of material they recieve soif failure does occur they have certification to prove what theygot what was ordered.
Could also have been in the machining process of the threads in which case there could be many more failures to come unless they're all done individually.
Thanks for the info, good stuff.