Are scope shades suppose to screw into each other?

[XDRoX]

I always assumed that scope shades were suppose to be sort of modular and could screw into each other to make a longer one.

I just ordered a second shade for this 50mm Simmons scope and to my surprise they don't screw into each other.

It's not a huge deal as I have another scope I can use it on, plus it doesn't really need any more shade, but still I was surprised.

[Carsgunsandchics]

In my experience, some do and some don't. My BSA does as well as Leupold.