Explain the phenomenon of 'Snap-Back' during the manual installation of internal spiral retaining rings and how to avoid it.

'Snap-Back' occurs when an internal ring, which is being compressed for insertion into a bore, is released too quickly or is not fully constrained, causing it to spring back violently to its free diameter. This can cause injury or damage to the bore's lead-in chamfer. To avoid this, technicians should use a 'tapered sleeve' (the inverse of a mandrel). The ring is compressed into the large end of the sleeve and then pushed through the sleeve into the bore. This provides continuous radial constraint. For manual installation, ensuring that the ring's gap is correctly oriented and using a controlled-compression tool is essential for safety and part integrity.