There are a number of uses for washers. Although most are used to distribute a load over a larger surface area, they are also employed where it is necessary to span oversize holes, to provide spring tension as well as sealing and insulating. There are different washer designs to perform these functions, the most common standard washers are flat while others have a slight conical shape or even wavy.
A flat washer is also commonly known as a plain washer, it is used as a bearing surface a nut or bolt head as well as spreading the load over a larger surface; this is particularly true when the fastener system is employed on soft material.
There are two types of standard washers that are used for general purposes. The most common is type “A” which has quite wide tolerances; this type of washer is used where refinement is not necessary. Type “A” washers are usually satisfactory for most uses. The other flat washer is type “B,” these washers are higher quality and have closer tolerances.
Conical spring washers:
Conical spring washers are normally employed in conjunction with unhardened screws where there is the potential of fastener elongation. These washers flatten when the load placed on them is approximately half the breaking load of the screw.
Conical spring washers are used to deal with the elastic properties of the joint. Connections tend to loosen and they do so in numerous ways. Although the initial tightening of the fastener is accomplished using torque, the joint loosens when the screw relaxes which it will. All metal under tension will “cold flow,” in the case of a screw or bolt this tends to loosen the joint.
A properly selected conical spring washer will reduce the effects of loss in preload by a factor of ten.
JTD Stamping is a leading Standard Washer Supplier and offers a wide selection of in-stock types and sizes for immediate delivery.