Gas engine stand off mounts??
cu. in.
If you picture a "T" nut as the letter "T" so that the flat part of the nut is up. The vertical leg seperated from the horizontal leg. I have a baggie full of broken ones in all sizes that I have collected over the years just to show people not to use "T" nuts in a high vibration enviroment. The last ones I added to my collection are from a 3W-100 that departed the front of the plane in flight. The back side of all 4 "T" nuts were still in the firewall, but the threaded shank was still on the bolts.