18-29-405.4.1.1 Hard lead floor flanges.
   Floor flanges of hard lead shall weigh not less than 1 pound 9 ounces (0.7 kg) and shall be composed of lead alloy with not less than 7.75 percent antimony by weight. Closet screws and bolts shall be of brass. Flanges shall be secured to the building structure with corrosion-resistant screws or bolts.