There are many different types of flat washers to choose from. Most are made from either stainless or carbon steel. A flat washer is generally designed to be used with threaded fasteners such as nuts or bolts. The main purpose of a flat washer is to distribute the weight or pressure applied to the object being bolted together.
Fender washers are generally used for light- to medium-duty applications. This may include auto body repair, plumbing repair or electrical work. Fender washers are often used in sheet-metal fabrication. They can also be used to hang drywall or install wood paneling. Fender washers usually have a larger outside diameter than standard washers.
Type-A flat washers are a series of steel washers. Type-A washers work within a wide range of tolerances and are ideally suited towards work that does not require a high level of refinement. Most type-A flat washers range in size from a No. 6 to 3-inch hole size. Outer diameters may range from 3/16 to 5 1/2 inches.
Type-B flat washers are a higher quality washer. These are available in No. 0 to 3-inch hole size. Type-B washers may be used in more specific applications where certain qualities may be necessary. Type-B washers come in different styles, including narrow, regular or wide diameter.
Nylon flat washers may be used instead of metal washers in certain applications. Nylon washers are lightweight and are better insulators than metal washers. They are not as strong but are more resistant to certain chemicals. Standard sizes for nylon flat washers are 1/4 inch, 3/8 inch, 1/2 inch, 5/8 inch and 3/4 inch.