Explain why the sequence of drilling, boring, and reaming produces a hole that is more accurate than drilling and reaming itonly. Q4 Why would machining operations be necessary even on net-shape or near-net- shape parts made by precision casting, forming. or powder metallurgy products. as described in preceding chapters? Explain. Q5 Explain the similarities and differences in the design guidelines for turning and for boring. Q6 Assume that you are asked to perform a boring operation on a large-diameter hollow workpiece. Would you use a horizontal or a vertical boring mill? Explain. Q6 in modern manufacturing, which types of metal chips would be undesirable and why? 23.41 Calculate the same quantities as in Example 23.1 for high-strength titanium alloy and at N 700 rpm. 23.42 Estimate the machining time required to rough turn a 0.50-m-long annealed copper-alloy round bar, from a 60-mm diameter to a 58-mm diameter, using a high speed steel tool. (See Table 23.4.) Estimate the time required for an uncoated carbide tool. 2344 A 7.5 mm-diameter drill is used on a drill press operating at 300 rpm. If the feed is 0.125 mm/rev, what is the MRR? What is the MRR if the drill diameter is doubled 23.45 In Example 23.4, assume that the workpiece material is high-strength aluminum alloy and the spindle is running at N 500 rpm. Estimate the torque required for this operation. Ch
