Hardness and Elasticity of Pitch for Optical Glass Polishing

Abstract

It has been our industrial practice to use pitch polisher for polishing optical glasses. But we have not had enough knowledge about the quantitativehardness and elasticity of pitch. Excepting some skilled workers, many people are troubling how to know about them. So we have tested them, with two gauges deviced in our laboratory. Discussed problems. are as follows.
1. Introduction.
2. Characteristics of test pieces.
3. Top figure of the spindle of gauge.
4. Pressure of the measurement.
5. Seasoning of the pitch.
6. Relation between. hardness & temperature.
7. Mechanism of gauge.
8. Relation between hardness & thickness.
9. Elasticity of pitch.
10. New device of measurement.
11. Observed effect in a few factories.