Drill Sizes - Numbered
Drill bits are available in hundreds of sizes, and the size designations include letters, numbers, decimals, and fractions. Decimal drill sizes further include both SAE units and metric units. This particular page presents the numbered drill size series. RF Cafe also has drill size tables for lettered drill size varieties.

These drill bits are almost always of the twist type that advance through the material being bored by turning in a clockwise direction as viewed from the top. They are said to be right-hand drill bits.

# Diameter

(in)

   # Diameter

(in)

   # Diameter

(in)

   # Diameter

(in)

   # Diameter

(in)
1 0.2280 21 0.1590 41 0.0960 61 0.0390 81 .0130
2 0.2210 22 0.1570 42 0.0935 62 0.0380 82 .0125
3 0.2130 23 0.1540 43 0.0890 63 0.0370 83 .0120
4 0.2090 24 0.1520 44 0.0860 64 0.0360 84 .0115
5 0.2055 25 0.1495 45 0.0820 65 0.0350 85 .0110
6 0.2040 26 0.1470 46 0.0810 66 0.0330 86 .0105
7 0.2010 27 0.1440 47 0.0785 67 0.0320 87 .0100
8 0.1990 28 0.1405 48 0.0760 68 0.0310 88 .0095
9 0.1960 29 0.1360 49 0.0730 69 0.0292 89 .0091
10 0.1935 30 0.1285 50 0.0700 70 0.0280 90 .0087
11 0.1910 31 0.1200 51 0.0670 71 0.0260 91 .0083
12 0.1890 32 0.1160 52 0.0635 72 0.0250 92 .0079
13 0.1850 33 0.1130 53 0.0595 73 0.0240 93 .0075
14 0.1820 34 0.1110 54 0.0550 74 0.0225 94 .0071
15 0.1800 35 0.1100 55 0.0520 75 0.0210 95 .0067
16 0.1770 36 0.1065 56 0.0465 76 0.0200 96 .0063
17 0.1730 37 0.1040 57 0.0430 77 0.0180 97 .0059
18 0.1695 38 0.1015 58 0.0420 78 0.0160    
19 0.1660 39 0.0995 59 0.0410 79 0.0145    
20 0.1610 40 0.0980 60 0.0400 80 0.0135    

  Thanks to Jeff M. for pointing out the previous error in the #61 - #80 values (they were shifted by one row).