How to choose a drill bit for tapping metric threads

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Drill diameter used before tapping metric threads　　　　　Nominal diameter, pitch, drill diameter, nominal diameter, pitch, drill diameter: 10.25, 0.75; 12, 1.75; 10.2, 1.2, 0.2, 0.25; 0.95; 11, 1.6, 0.35; 1.25, 1.25; 10.8, 2.0, 0.4, 1.6, 1.5; 10.5, 2.5, 0.45; 2.05; 14, 2, 12, 0.35; 2.15; 113, 30.5, 2.5, 1.25; 12.8, 0.35; 2.65, 1.5, 12.5; 40.7, 3.3; 162, 14, 0.5, 3.5; 115, 50.8, 4.2, 1.5, 14.5, 0.5, 4.5; 18, 2.5, 15.5; 61, 15, 117, 0.75, 5.7, 1.5, 16.5, 8, 1.25, 6.8; 20, 2.5, 17.5, 0.75, 7.2; 119, 17, 1.5, 18.5, 10, 1.5, 8.5; 22, 2.5, 19.5, 0.75, 9.2; 121, 19, 1.5, 20.5, 1.25, 8.8; 243, 21　　　1231. For materials with high plasticity, such as steel, D = d – t². For materials with low plasticity, such as cast iron, D = d – (1.04 – 1.08)t, where D is the drill diameter, d is the nominal diameter, and t is the pitch. 3. Bold numbers refer to coarse-threaded threads