Drill bit size index
No Inches mm
80 0.0135 0.3429
79 0.0145 0.3680
78 0.0160 0.4064
77 0.0180 0.4572
76 0.0200 0.5080
75 0.0210 0.5334
74 0.0225 0.5715
73 0.0240 0.6096
72 0.0250 0.6350
71 0.0260 0.6604
70 0.0280 0.7112
69 0.0292 0.7417
68 0.0310 0.7874
67 0.0320 0.8128
66 0.0330 0.8382
65 0.0350 0.8890
64 0.0360 0.9144
63 0.0370 0.9398
62 0.0380 0.9652
61 0.0390 0.9906
60 0.0400 1.0160
59 0.0410 1.0414
58 0.0420 1.0668
57 0.0439 1.0922
56 0.0465 1.1811
55 0.0520 1.3208