Official Answer
Answer
For high-volume assembly of internal spiral rings (bore mount), a 'Sleeve and Plunger' tool is used. The sleeve has a tapered internal bore that gradually compresses the ring to a diameter slightly smaller than the housing bore. The plunger then pushes the ring through the sleeve until it reaches the groove, where it snaps into place. The taper angle should be shallow (typically $3^{∘}$ to $5^{∘}$) to minimize the force required and avoid scratching the ring's surface. This method is standard in automotive transmission assembly lines, as it prevents the 'over-compression' that can occur with manual pliers and ensures that the ring is not 'spiraled' in, which could damage the groove edges.
