Official Answer
Answer
'Snaking' refers to the non-flatness or axial runout of a spiral retaining ring in its free state. It is typically caused by residual stresses from the coiling process that were not fully relieved or by uneven heat treatment. In an assembly, a snaked ring will not sit flat against the groove wall, creating 'point loading' rather than uniform circumferential contact. This significantly reduces the initial thrust capacity and can cause the ring to 'pop out' under much lower loads than calculated. For high-RPM applications, a snaked ring creates an unbalanced mass, leading to vibration. Quality control should specify a maximum allowable flatness tolerance, and rings should be checked on a surface plate using a feeler gauge.
