As hard as nails and Cold-blooded

Cold-blooded and as hard as nails are semantically related. In some cases you can use "Cold-blooded" instead an adjective phrase "As hard as nails".

Cold-blooded adjective - Having or showing a lack of sympathy or tender feelings.

As hard as nails and cold-blooded are semantically related. Sometimes you can use "As hard as nails" instead an adjective phrase "Cold-blooded".