Official Answer
Answer
A Gap Type wave spring has a physical separation between the ends of the wire, while an Overlap Type has the ends overlapping. During installation into a bore, the Gap Type can be compressed radially more easily. However, the Overlap Type provides a continuous $360^\circ$ contact surface, which is essential in applications where the spring must prevent the ingress of contaminants or where a consistent radial pressure is needed. The 'Overlap' can cause a slight height variation at the junction point, which must be accounted for in the housing depth design. If the gap in a Gap Type spring closes completely during compression, it can cause the spring to behave like a solid ring, leading to a catastrophic spike in load.
