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.
Sources of Calcium. Food. Milk, yogurt, and cheese are rich natural sources of calcium and are the major food contributors of this nutrient to people in the United States [ 1 ]. Nondairy sources include vegetables, such as Chinese cabbage, kale, and broccoli.Spinach provides calcium, but its bioavailability is poor.hen calcium intake is low or ingested calcium is poorly absorbed, bone breakdown occurs as the body uses its stored calcium to maintain normal biological functions. Bone loss also occurs as part of the normal aging process, particularly in postmenopausal women due to decreased amounts of estrogen.