... CNC /15 FMS* 0 .22 0.34 2. 50Fig. 1. 27 Costs associated with the examples of Figure 1. 26 , a–g as in Table 1. 6Childs Part 1 28 :3 :20 00 2: 35 pm Page 29 non-productive tool change time, associated ... ∅3 ≈ 1 – 3 ≈ 1. 00∅6 ≈ 1. 5 – 5 ≈ 1. 25 12 ≈ 3 – 8 ≈ 1. 50solid carbide ∅3 ≈ 7 ≈ 3.00∅6 ≈ 15 ≈ 3.75 12 ≈ 60 ≈ 4.50Childs Part 1 28 :3 :20 00 2: 35 pm Page 23 If milling were carried out at the ... be 2. 5 GPa.Then, from equation 1. 2( b), for fd = 1 mm 2 , a power of 1 kW is needed at a cutting speedof 25 m/min (for HSS), 5 kW is needed at 12 0 m/min (for cemented carbide) and 15 kW 26 IntroductionFig....