Fuel Line Fittings - Self Locking Threads?

[paulo57509]

Regarding a couple of inverted flare fuel lines on both the Legend and the LS:

1. Fuel filter inlet hard line fitting.
2. Hard line to fuel rail fitting.

Both of these threaded connections feel as though they're cross threading when re-connecting them. The effort to start and tighten until seated is much more than usual, there's no visible thread deformation/galling, etc.

I'm wondering if these connections might have some kind of self-locking thread form like Spiralock?