1, the spring washer expansion ring phenomenon, generally not the spring washer itself.

2, the spring washer that produces the expansion ring must be subject to a radial external tension, and the external tension comes from the tightening axial force generated by the tightening torque.

3, the outer chamfer of the nut supporting surface causes the radial component of the axial clamping force, which makes the opening of the spring washer expand. The smaller the diameter of the chamfer, the more likely it is to swell.

4. Adding a flat washer between the nut and the spring washer helps to slow down or prevent the expansion of the ring, but the flat washer is too thin or too soft to prevent the expansion of the ring.

5, spring gasket hydrogen embrittlement fracture is generally caused by unreasonable heat treatment process, and there is no timely hydrogen removal treatment after electric galvanizing.