Tub Drain has a chunk missing from threads

We're installing a freestanding tub with a center drain. The drain is leaking slightly despite a generous supply of plumber's tape on the threads. We noticed a chunk missing out of the threads in one spot. Could that be causing the leak? Should we just use more tape to try to fill the missing piece or should we get a new drain?

We purchased the tub last May and are just getting around to installing it so I doubt we can go back to the vendor and get a new drain. They did send 2 drains (different color pop tops), but the other drain looks a bit flimsy.

thanks,
shawna

The threads, tape, pipe compound or anything else has NOTHING to do with preventing leaks under the tub. All they do is keep the water inside the tub when the plug is closed. Underneath leaks are caused by a bad gasket seal between the bottom of the tub and the drain fitting. Did you use the rubber gasket there?

hj is right. the seal in the washer under the tub.
No goo or tape should be on the threads. I've seen cases where tape "prevented" a tight seal for the drain.

I use a little plumbers putty "under" the flange, and then thread that down into the awaiting tub shoe. The rubber gasket goes between the shoe and the bottom of the tub. The putty doesn't do much though. It's the gasket between the tub and shoe that does the heavy lifting.