Hello Newf,
I'm sorry that you had this accident so please call Axiom and we'll fix you up, however, in defense of the Axiom Full Metal Bracket (FMB), from your photos and our tests at the plant, there is no question the failure resulted from your over-tightening the center bolt when you attached the center to the FMB. We do have a large warning about it in the FMB instructions(
http://www.axiomaudio.com/manual_fmb.html). In the ten years of my being with Axiom, we have had only one other failure of the FMB and it was caused by the owner over-torquing the bolt.
If you over-tighten the bolt eventually something has to give. In your case the collar part of the T-nut that creates the sandwich between the inside and outside of the cabinet wall has separated completely from the rest of the T-nut. Normally you would feel it getting very tight and then get loose again as you pulled the remaining part of the T-nut through the hole and then it would get tight again as the remains of the T-nut came in contact with the FMB.
Give us a call at the toll-free number.
Regards,
Alan
