Selecting the optimal washer for any assembly applications is critical for its success. Selecting will be challenging if you do not know the basics of washers. Basically, washers are multipurpose fasteners that are utilised to spread the load of fasteners (screw, nut or bolt). It is also used to secure the fasteners, which is a way to reduce the chances of loosening.
You should be able to distinguish the different types of washers vis-à-vis washer dimension and materials to make an informed decision. Generally, there are three types of washers – plain, spring and locking washer. The most common type is a spring washer. It is used to prevent the loosening of fasteners against vibrations. Spring washers are also called disc springs.
When considering spring washers, you have to keep in mind that taller and thicker ones can bear more loads under stress. It is known for its irregularities that have the capability to compress with right resistance to get back to their original shape. There is two types of spring washer load – static or dynamic load. The static load will retain the load at the same time it can exceed the elastic load rating. The dynamic load will act as a flexing spring, where the limit should not exceed the elastic load rating.
In the production of spring washers, the methods include stamping, turning, heat treatment, scragging and inspection. There is an online steel washer supplier that you can consider. This is for a convenient and easy procurement of spring washers and its types like Belleville, crescent, dome, finger, wave, and single wave. Here are other things that you should consider:
The dimension of spring washer is critical to a successful operation. Spring washers are valued for their small size. The dimensions are as follows:
A. Outer Diameter (OD): It refers to the width of the straight line across the washer.
B. Inner Diameter (ID): It refers to the width of the washer across the bored hold.
C. Diameter Across Slots (DAS): It is the measurement of the washer but without the sloped flanges. In the case of Belleville washers, DAS is the same with ID.
D. Diameter of Center Rotation (DCR): It refers to the distance between the center points of the flanges.
E. Cone Height (CH): The measurement of the washer from the lowest point to the highest while at rest. The standard CH should not be more than 40% of the plate’s thickness.
F. Plate thickness (T): It refers to the width of the constructed washer.
G. Washer envelope: It refers to the space allotted for the deflection of the washer.
Spring washer material
The operation of the washer is dependent on the material used. Spring washer materials should have acceptable elastic limits and good tensile strength to be effective. To predict a deflection capability and material load, Young’s Modulus is used. The materials include:
A. Steel: It is the most common material. It is valued for its high tensile strength and ease of process.
B. Copper alloys: The strength value of copper alloy is lower than steel.
C. Nickel-chrome alloys: This material has high tensile strengths but not little elastic ratios.