Page 226 - Demo

224 ISCAR DEEP HOLE DRILLINGThe value of nose angles has an influence on both the drill and the drilled hole.Increasing the outer angle and decreasing the inner angle will result in an undersized hole, good straightness, and bad tool life (Figure 6.5.2.7).Decreasing the outer angle and increasing the inner angle will result in an oversized hole, bad straightness, and good tool life (Figure 6.5.2.8).Figure 6.5.2.7small inner anglelarge outer angleFigure 6.5.2.8large inner anglesmall outer anglePad FormISCAR%u2019s pad forms, also called drill profiles, were specially designed for specific machining applications (Figure 6.5.2.9). The pad form defines the geometry of cutting tip at cross section. All cross-section profile parameters such as P, La, must be precisely matched to the workpiece material properties.