These metal knobs provide the perfect heavy duty solution to your clamping and hand fastening needs. 100% solid stainless steel versions are popular in the food service and medical industries. These metal knobs are beautifully polished to a mirror finish. Available materials include; cast iron, aluminum, and 300 grade stainless steel. Some of the available finishes and plating's include but are not limited to: zinc, anodized, passivated, polished, brushed, and painted.