The issue is often not the material used, but the thickness of the material and the quality of the finish applied to the material. Knobs and pulls made from solid bronze, solid brass, solid steel etc. are going to hold up better than hollow knobs and pulls. They will feel better in the user’s hand – a quality difference you can easily feel. They even sound better, strange as that may be, because they don’t have a hollow “tink” sound when hit with a ring or bracelet when being used. Hollow products are usually made of cast zinc. These products can be fine. Top Knobs has some cast zinc hollow products where the intricate design of the knob can only be created by using cast zinc. For such products we use a high-grade cast zinc alloy that is thicker, stronger, and long-lasting. Finish is just as important as the metal used. Top Knobs has a lifetime warranty against defects in materials and craftsmanship.