Metal doors on Metal Doorways?

Hello, I am reading everywhere that it takes 3 c4 for a metal door on a metal doorway? Is that correct? It takes 2 for a metal door on a wooden doorway. Thank you in advance.

All metal doors take 2 c4 or 11 grenades no matter what type of doorway they are in.

This. For this reason, it is still just as easy to steal a metal base as it is a wood base. :smiley:

That is what I thought, just been reading up on things here and came around a thread with everything explained on how to destroy it, and saw it took 3 for metal doors on metal doorways. Thanks again.