jewel bearing การใช้

It was due to the fact that the increased demand for Jewel bearing for military purposes.
A "'jewel bearing "'is a plain bearing in which a metal jewel-lined pivot hole.
Temperature-compensated balance wheels began to be widely used in watches during this period, and jewel bearings became almost universal.
Hard stones such as ruby and sapphire were often used as jewel bearings to decrease friction and wear of the pivots and escapement.
The needle is mounted on a low-friction pivot point, in better compasses a jewel bearing, so it can turn easily.