Go to a hardware store and get the size bit you need that is made for metal. Most cast iron isn't really hard unless it is white cast iron. If the hole is over 3/16, pre-drill it with a small bit first. It might be a good idea to use some cutting oil to.
Other foods that are high in calcium include: 1  Spinach. 2  Kale. 3  Okra. Collards. 4  Soybeans. White beans.  Some fish, like sardines, salmon, perch, and rainbow 1  trout. Foods that are calcium-fortified, such as some orange juice, oatmeal, and breakfast  cereal.
Calcium carbonate, nature's most concentrated source of calcium, delivers 500 mg of elemental calcium in each VIACTIVâ¢ Calcium Soft Chew. The calcium in VIACTIVâ¢ has been clinically demonstrated to be absorbed as well as the calcium from low-fat (1%) milk.