In this paper continued from part 1, we made an experiment on the effect of lapping pressure, lapped quantity, sphericity of balls used and supplying interval of lapping compound upon cutting resistance when the radius of steel balls was about 1 mm.
Then we found following results,
(1) in the case of cast iron lap, there were limits in suitable lapping pressure according to the ball size, and the supplying interval of lapping compound had no influence on them,
(2) in the case of suitable lapping condition, the cutting resistance was proportional to lapping pressure or the lapped quantity, and its proportional constant was different according to lap materials,
(3) in the case of nylon lap, lapped quantity was not much connected with lapping pressure, but sphericity was proportional to lapping pressure,
(4) in the case of cast iron and nylon lap, variation of the cutting resistance was comparatively small, and the sphericity increased when cutting resistance decreased gradually.