When choosing between nails and screws, remember that nails are less brittle and so give more shear strength. They may bend under stress, but they seldom crack. Screws can be either stainless steel or brass. Brass has more shear strength than stainless steel. Nails are made of iron or steel. These metals have different properties depending on how they are made. The type of metal used to make nails affects their strength. For example, cold-rolled nails are stronger than hot-rolled nails. Cold-rolling means rolling the metal at a low temperature; hot-rolling means rolling it at a high temperature. Stronger nails are also less likely to break under pressure. Screws are also made of metal. But instead of being rolled into shapes like nails, they are stamped out of sheet metal. This process leaves very little if any room for error, so they are always stronger than nails. Of all the fasteners available, screws are the strongest. Fastener strength is important when you're working with heavy items. Nails tend to be weaker than screws because they are not as structured. That means they will deform under force sooner than screws will. If you need to hold an object together with nails, then use a few pieces rather than one large one.