Which Iphone bends the least (6 or 6 plus) bend the least?

I was thinking of getting the 6 or 6 plus but I was wondering what bends the least? I do put my phone in my pocket sometime especially when I'm walking but sometime when I sit down it's in my pocket.

Added (1). Note: I will get a case but which one bends the least?

Added (2). Note: And I will put it in my front pocket for whatever pants/shorts I wear.

The 6 bends the least. Its smaller so it doesn't take as much pressure as the 6 plus.

It takes ALOT of pressure to actually bend it. Its metal, its not like its plastic.