AGA T2 sharp & hard threads

[Balders]

I've bought 2 of the T2s recently but discovered the threads are very sharp. The grade of SS is also hard compaired to the brass of a standard 510 female connector
These have almost destroyed the threads on my Vamo And yes, I'm very careful when removing/replacing tanks & I only ever finger tighten (I had a go at a friend for over tightening his Ego)

Anyone else noticed this? Have I just got a couple of "Friday afternoon specials"?

Thanks