assign strength to an object?

is there a way to assign strength to an object so that it will not break when physics are applied?

I have made this chain rig to hold up a big mass but it keeps breaking when i simulate the physics.


I have tried playing with the mass sliders but no matter what i try it continues breaking in different places.

here is my project if anyone would like to take a look i would apreciate it
MIGHTY_MAGNET.blend (1.09 MB)