A washer, a machine component that is used in conjunction with a screw fastener such as a bolt and nut and that usually serves either to keep the screw from loosening or to distribute the load from the nut or bolt head over a larger area. For load distribution, thin flat rings of soft steel are usual.
Types of washers
Carbon steel is a popular choice of materials for washers because of its high strength. When carbon is added to steel, it creates a stronger metal. The downside is that carbon steel lacks the rust- and corrosion-resistant properties of stainless steel, which is another common material in which washers are made.
There are three main types of washers: plain washers, spring washers and lock washers. Within each of these categories are more specialized forms that serve unique purposes.
Washers may shift or move during the tightening process. This action affects the torque tension of the joint and can result in an inaccurate fit that will loosen or fail over time. In critical joints, even a small amount of movement can lead to disaster.
These washers are thicker than most flat washers, so they can withstand exceptionally high loads. Their build tends to mimic that of a standard flat washer.
Steel Grade Material & Treatment Tensile Strength
Grades: Flat washers do not have a specific grade as traditional fasteners such as Grade 5 or Grade 8 bolts do however there are two common types of steel used. Standard steel flat washers (low carbon steel) are not rated for hardness. Hardened steel flat washers.