Heavy chains

I have to wear latex and 2 days in the week o work from home locked in latex with chains between ankle, wrists and neck.

I would love to make the chains heavier, but can not find 
In the normale hardware store any heavy 

Does anyone have tips?

I have to wear latex and 2 days in the week o work from home locked in latex with chains between ankle, wrists and neck.

I would love to make the chains heavier, but can not find 
In the normale hardware store any heavy 

Does anyone have tips?

Since you seem to be in the Netherlands, you might look with google for "hijsketting". They are heavier than what you can buy at for instance Praxis. "Ankerketting" gives also some potentially interesting hits.

If you’re close to the ocean, see if you can find some ships anchor chain.
Bet that will be heavy enough for you.