Bruce wrote:

I do chin ups from a bar that hangs from 1 eye bolt in the ceiling
and I
weigh around 225. It's in a 2X6 though. I'd be much more worried about
the 2X4 breaking than the eye bolt coming out.
snip

The moment of inertia for a rectangle is: (b*h^3)/12 where b=base &
h=height.

The moment of inertia is a measure of a beam's resistance to bending.

Do the math and you will find a 2x6 rectangle has a moment inertia of
4.5 times that of a 2x4 rectangle, thus 4.5 times stronger in
resisting bending.

Lew