Figure 1 and Figure 2, below, are sketches of the cross section of a chamfer with a ball bearing (of radius r) set respectively, inside an existing chamfer, and upon the top of the chamfer hole.
Formula (ia) is used when the ball bearing sits inside the chamfered hole, as in Figure 1. Formula (ib) is used when the ball bearing sits on top of the hole, as in Figure 2.
Formula (ii) is used to determine the height of the ball bearing above or below the adjoining surface (h) for a chosen chamfer diameter (D). Formula (ii) applies to Figure 1 only.