Abstract
This paper gives results of an investigation extending over a period of more than ten years, the purpose of which has been to determine the fundamental laws governing milling, turning, planing and drilling operations on the various metals and alloys used in machine construction. In addition to a very large number of tests made on milling machines constructed by the concern with which the author is connected, those reported by Frederick W. Taylor and Professors Bird and Fairfield in the Society’s Transactions have been subjected to analysis, the following variables being studied:
1 The efficiency of the machine
2 The rate of metal removal (cu. in. per min.)
3 The average thickness of chip before distortion
4 The front rake on the cutting blade
5 The material being cut
6 The spiral angle or shear on the cutting blade
7 The condition of the cutting tool, sharp or dull.
The author’s results are presented in the shape of formulas and tables by means of which the power required to machine metal in any given case may be calculated, and an example of their use is worked out in detail. Such calculations, however, are tedious, and the author has accordingly devised a slide rule for the purpose, a description of which forms an appendix to the paper.
