OIL CUP/ OIL SINK

1. Circular recess in a bearing (jewel, cap jewel) serving as an oil reservoir for the pivots of an arbor.
2. A tool designed to hold a small quantity of oil for lubricating a movement. The watchmaker takes the required amount of oil from it using an oiler and then applies it to the part of the movement to be lubricated.

Useful links:

– Oils
– Lubrication