Study of Complex Helical Drill with a “S” Type Chisel Edge Tip Orient to Carbon Fiber Reinforced Plastics

Figure 4

The shape of blade-grinded drills. (a) 2ϕ = 100°. (b) 2ϕ = 110°. (c) 2ϕ = 115°. (d) 2ϕ = 120°. (e) 2ϕ = 125°. (f) 2ϕ = 130°. (g) 2ϕ = 140°. (h) 2ϕ = 150°.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)