What Are Flat Washers?

If you have ever put any kind of flatpack piece of furniture together or done any kind of home improvement job, then you have probably run into washers. They are used in a lot of places, from your faucets to the studs in your wall. The most common kind of washer is the flat washer. You may also hear them called plain washers.

Flat Washers

These washers are generally just a simple circle of metal that has a circle punched into the middle of it for a screw or bolt to be inserted. The washers come in a variety of interior and exterior diameters so that they can be used in a number of situations. It's important to make sure that the interior diameter is the right size for the screw that it is paired with. If the diameter is too big, the head of the screw will not be supported, which will negate part of the washer's job. So, what do washers do when they are installed in pieces of furniture or in the wall of your house? 

Increase the Surface Area

One job that the flat washer has is to increase the surface area of the head of the screw. Increasing the surface area of the head of the screw will do a few things. One is that it guarantees that the head of the screw won't sink down into the area where the screw is fastened. Increasing that area will also make it so that the surface pressure exerted by the screw head is spread out, which lessens it at any one point. A screw head that is 1/4 inch in diameter is going to exert a lot of pressure at that one particular point. However, if a washer is placed under that screw, the surface pressure that is exerted by that 1/4 inch screw head is going to be spread out over the 2-inch diameter of the washer. The same amount of pressure is still being exerted, but it is now spread out over a larger area, so it is going to be less at any one point. This can be really good when the screw is going into a softer material like softwood or metal like aluminum or tin. 

Flat washers show up in a variety of places. The washers have several different jobs to do, depending on where the washer is going to be installed.