City Guilds Model Questions Vol1 2017 Engineering Question 22

A cylindrical steel workpiece 150 mm long and 50 mm in diameter is to be turned to a final diameter of 48 mm. Two tool materials are available: carbide with a maximum cutting speed of \(120\) m·min⁻¹ and high‑speed steel (HSS) with a maximum cutting speed of \(30\) m·min⁻¹. The machine can run at up to \(3000\) rpm. The feed per revolution is \(0.2\) mm and the depth of cut is \(1\) mm. After turning, a 10 mm diameter hole is to be drilled through the centre of the part using a drill whose maximum cutting speed is \(80\) m·min⁻¹ and a feed of \(0.15\) mm per revolution. Determine (a) which turning tool should be selected, (b) the minimum time required for the turning operation, (c) the spindle speed for drilling, (d) the drilling time, and (e) the total machining time in minutes (rounded to two decimal places).