Washers play an important role in many everyday products and assemblies. With their disc-like shape, they are able to distribute the load of threaded fasteners. You can drive a screw or bolt through the center of a washer. The head of the screw or bolt will then press against the washer, thereby distributing the fastener’s load. While washers are relatively easy and straightforward to use, however, there are several common mistakes you should avoid with them.
#1) Wrong Inner Diameter Size
You need to choose washers in the right size. If the inner diameter is too big or small, the washer may not fit properly. The inner diameter represents the width of the hole. If it’s too big, the head of the fastener may slip through the hole. If the inner diameter is too small, the shank of the fastener may not fit. The inner diameter should be slightly wider than the shank for a proper, secure fit.
#2) Using Standard Washers in High-Vibration Applications
If you’re planning to use them in machinery or appliances, you may want to avoid standard washers. Standard washers are susceptible to loosening when exposed to vibrations. It may not happen immediately, but constant exposure to vibrations can cause traditional washers and the threaded fasteners with which they are used to loosen. Fortunately, there are specialty washers available that can withstand vibrations, such as cupped, disc and split washers.
#3) Over-Tightening
Another common mistake to avoid when using washers is over-tightening. Torque is a rotational force. To install a washer, you’ll need to place a threaded fastener through the center of it, followed by turning the fastener (typically with a screwdriver). Using too much torque, though, may damage the washer. Most washers are thin. If you apply too much torque, you may crush and deform the washer or even the underlying part being fastened.
#4) Overlooking Material Compatibility
Pay close attention to the material when choosing washers. Washers are available in different materials. If you use a washer in a material different than that of the fastener, it may lead to corrosion. Galvanic corrosion, for instance, occurs when two dissimilar metals make contact in the presence of moisture. An aluminum washer and a stainless steel bolt can lead to this phenomenon.
#5) Assuming Spacers and Washers Are the Same
Spacers and washers aren’t the same. While they are both used in conjunction with threaded fasteners, they are used for different purposes. Spacers are used primarily to create space between the head of a threaded fastener and the part being fastened. Washers, on the other hand, are used primarily to distribute the fastener’s load.
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