1st. The diameter of the work, all other conditions being equal.
2nd. The degree of hardness of the metal, all other conditions being equal.
3rd. Upon the shape of the cutting tool; and—
4th. Upon the quality of the steel composing the cutting tool, and the degree of its hardness.
That the diameter of the work is an important element in small work may be shown as follows:—
Fig. 1153.
