Spring washers are usually made of 65MN spring steel or 70 # carbon steel, 3Cr13, or stainless steel materials SUS304 or SUS316, as well as phosphor
bronze materials. Next, Shuifu Hanyang Machinery Technology Co., Ltd. will take you to understand the function of the elastic pad.
Main purpose
Used under the nut to prevent it from loosening.
It is stated in national standards.
The methods to prevent nuts (or bolts) from automatically loosening in mechanical design and production include:
1. Add spring washers; (Simple and easy to do)
2. Use hexagonal slotted nuts and split pins; (Year on year increase in processing steps)
3. Add a stop washer; (Year on year increase in processing steps)
4. Insert the steel wire into the hexagonal head hole of the hexagonal bolt. (Year on year increase in processing steps
Spring washers are used for anti loosening, such as adding spring washers to the bolts connecting the motor and the machine base, because if the
motor vibrates without spring washers, the nuts will loosen. Generally, fasteners on equipment with vibration are equipped with spring washers, while
flanges generally do not require washers. The presence or absence of spring washers on flanges is related to the medium flowing through the pipeline.
If it is prone to pulse generation, it is best to add spring washers. There are also high-speed fluid pipelines with frequent changes in diameter, so do not
generalize. On some valves, spring washers are required to be added to the flange of the packing box cover, and the selection of spring washers is
included in the Quick Easy Optimization automation selection.
Main differences
Spring washers can play a role in preventing loosening and increasing pre tightening force, while flat washers do not have this function. They can be
used to increase the fastening contact area, prevent friction between bolts and workpieces, protect the surface of connecting parts from scratching the
workpiece surface when bolts and nuts are tightened.
But some important connections, such as those that rely mainly on compression to generate friction and transmit power, cannot use spring pads. Using
them will reduce the rigidity of the connection and may even lead to accidents. When the strength of the connected component is low, flat washers or
flange bolts are used to increase the contact area. When there is vibration, pulse, or significant temperature fluctuations in the medium, spring washers
must be used.
Reason for fracture
1. When the spring washer swells, it is generally not a problem with the spring washer itself.
2. The spring washer that experiences bulging will inevitably be subjected to a radial outward tension, which is caused by the tightening axial force
generated by the tightening torque.
3. The outer chamfer of the nut support surface generates a radial component of the axial clamping force, causing the opening of the spring washer to
expand. The smaller the chamfer diameter, the greater the likelihood of bulging.
Adding a flat washer between the nut and spring washer can help slow down or prevent the occurrence of bulging, but a flat washer that is too thin or
too soft cannot prevent bulging.
5. The reasons for hydrogen embrittlement fracture of spring washers are generally due to unreasonable heat treatment processes, as well as failure to
perform hydrogen removal treatment in a timely manner after zinc electroplating.
