Not in armor (which doesn't exist where this dagger is from) or directly at bone, but as I just said, it is (was) used to stab into the soft spot in the front side of a persons neck. The point where it starts to get pointier (the "blade") is almost 20 cm long. Doesn't matter if it goes so far in it hits bone and/or breaks inside of you, you'd still be gurgling and choking on your blood, and I'd be standing above you whistling to the gurgling sound.

Or just walk away like you know not of what's going on