This is made from virgin 99.98%+ pure copper.

If you're concerned about the grade of the metal it's important to point out that sink is made from 18 gauge copper, which is flexible enough to bend with your hands.

One main reason each sink is hand hammered is the hammering helps work harden the metal to make it about as strong as automotive steel. It will bend with enough force, 18 gauge isn't the thickest gauge available, but it won't fail with your standard bathroom use.

i have hammered 18" in my kitchen no issues