These custom locking tee nuts were manufactured using 304 stainless steel material and were offered in both plain and glass bead blast finish.  It took a few tooling adjustments to finally get the locking tooth feature just right and they are internally threaded all the way through with 1/4-20 thread.  The outside diameter of the flange is set to 19MM and overall height to 12MM.  Full certs were provided with the parts.