Cold roll steel 16 gauge (0.58"); just a bit thicker for added strength. The original was 18 gauge (0.048"). Between the added thickness and my bending method, this one is stiff and extremely flat, solving that "squealing" issue. The added thickness does not take away any "Twang". Use the Broadcaster saddles for that woody throaty tone, or the brass saddles for a thicker warmer tone.