Any drilling project must consider the diameters of the drill bits. The size of the drill bit influences how big the hole will be, and different sizes are suitable for various materials and uses. Anyone who uses a drill, whether for DIY projects or industrial applications, must be familiar with drill bit sizes. The fundamentals of drill bit sizes and how to select the appropriate size for your job are covered in this article.
Types of Drill Bits
Drill bits come in a variety of forms, each with a unique function and set of characteristics. Here are a few of the most popular drill bit varieties and their typical numerical values:
- Twist Drill Bits: The most popular kind of drill bits, these can be used to drill into plastic, metal, and wood. Typically, the numerical value falls between 1/16 and 1 inch.
- Brad Point Drill Bits: These have a pointed tip that helps keep the bit from wandering and are made specifically for drilling into wood. Typically, the numerical number falls between 1/8 inch and 1 inch.
- Spade drill bits: are used to make large holes in soft materials like wood because they have a flat, paddle-like tip. Typically, the numerical number falls between 1/4 inch and 1-1/2 inches.
- Forstner Drill Bits: These are used to drill holes with flat bottoms in soft materials like wood. Typically, the numerical number falls between 1/4 inch and 2 inches.
- Hole Saw Drill Bits: These are used to drill huge holes in a variety of materials, including metal and wood. Typically, the numerical number falls between 3/4 inch and 6 inches.
- Masonry Drill Bits: These are used to drill through masonry materials including brick, concrete, and more. Typically, the numerical number falls between 1/8 inch and 1 inch.
- Drill bits for countersinking: screws and other fasteners are known as countersink drill bits. Typically, the numerical number falls between 1/8 inch and 1 inch.
- Step drill bits: are used to drill holes of various diameters since they have several stepped sizes on a single bit. The numerical value usually falls between 1/4 and 1-3/8 inches.
- Auger drill bits: are used to make deep holes in soft materials like wood. Typically, the numerical number falls between 1/4 inch and 1-1/2 inches. can be as small as 0.05 mm, while the largest can be several inches in diameter.
Drill Bit Sizes
Typically, drill bit sizes are expressed in inches or millimeters. The diameter of a drill bit, or the distance across the widest point of the bit, establishes its size. The size of the hole that can be drilled increases with diameter. While the largest drill bit sizes can have a diameter of several inches, the smallest can be as little as 0.05 mm.
Between 1/16 inch and 1 inch are the most popular drill bit sizes, with smaller sizes being utilized for finer work and bigger sizes for more demanding applications. For instance, a 1 inch bit would be better for drilling large holes in heavy metal or wood, while a 1/16 inch bit would be suitable for drilling little holes in delicate materials like jewelry.
The material being drilled must be taken into account when selecting a drill bit size. Larger bits can be used to drill through softer materials like wood and plastic, whereas smaller bits are needed to drill through tougher materials like metal and concrete. The material being drilled can be protected from injury by selecting the proper bit size, and the hole will be the appropriate size and shape for the task.
The type of drill being used is another aspect to take into account when selecting a drill bit size. The size of the drill bit that can be used may be restricted by the chuck diameters of various types of drills. Verify that the drill bit being used is compatible with the drill before using it.
One typical error when selecting drill bit sizes is presuming that the size of the bit and the hole that will be drilled are the same. This isn’t always the case, though, as the drill bit’s angle and the material being drilled can both alter the size of the hole. Prior to beginning the real drilling operation, it is wise to test a drill bit on a scrap of material.
How to Measure Drill Bits
Several techniques can be used to measure drill bits. These are three typical methods for measuring drill bits:
- Using a ruler or tape measure: Place the drill bit on a level surface and measure the distance between the ends of the bit. To achieve an accurate measurement, be careful to take it from the farthest places on each end.
- Making use of a drill bit gauge: A drill bit gauge is a little gadget with a variety of holes that range in size. Simply place the drill bit into the hole that it fits into most comfortably to use it, and the gauge will display the drill bit’s size.
- Using a micrometer: A micrometer is a highly accurate measuring instrument that may be used to determine the diameter of drill bits. To use it, set the drill bit in between the micrometer’s two anvils and gauge the bit’s size using the micrometer’s reading scale.
Whatever method you choose, be sure to thoroughly clean the drill bit first to achieve an accurate measurement.
Metric Drill Bit Sizes and Country Using
Metric drill bit sizes are commonly used in countries that use the metric system. Here are some of the most common metric drill bit sizes:
- 1.0 mm
- 1.5 mm
- 2.0 mm
- 2.5 mm
- 3.0 mm
Countries that employ the metric system, a method of measurement based on the International System of Units, utilize metric drill bit sizes (SI).
The majority of nations on earth employ the metric system, including:
Canada
Mexico
Australia
In New Zealand
most nations in Asia, including China and Japan, most nations in Europe, including the United Kingdom
majority of South American nations majority of African nations
The imperial system, which uses inches, feet, and yards, is still in use in some nations, including the United States. Drill bit sizes are commonly measured in inches rather than metric sizes in the United States.
Drill Size Chart for Number and Letter Gauges
A helpful resource for choosing the appropriate drill bit size for various applications is the drill size table for number and letter gauges. For each number and letter gauge, the chart indicates the drill size in inches, ranging from 80 to 10. The drill bit size increases as the gauge number drops. For jobs like drilling screwholes or making pilot holes for bigger drill bits, this chart is especially helpful. The final product will be more secure and effective if the proper drill bit size is chosen to guarantee that the holes are the proper size for the intended use.
Drill Bit Size Gauge
A gadget used to determine drill bit sizes is called a drill bit size gauge. Typically, it comprises of a flat piece of metal or plastic with numerous holes labeled with the appropriate bit sizes bored into it. Simply place the drill bit into the hole that corresponds to its size to use the gauge, and the gauge will show the size of the bit. This is a useful tool to have in a workshop or tool box since it enables you to rapidly determine the ideal drill bit size for a task, assuring accuracy and effectiveness. For even more accurate measurements, digital drill bit size gauges that measure the bit’s diameter using sensors are also available.
Drill Size Chart – Fractional Sizes
Drill Size (in) |
Diameter |
Drill Size (in)
|
Diameter |
|||
Inches (in) |
Millimeters (mm) |
Inches (in) |
Millimeters (mm) |
|||
1/64 |
0.0156 |
0.3969 |
49/64 |
0.7656 |
19.4469 |
|
1/32 |
0.0313 |
0.7938 |
25/32 |
0.7813 |
19.8438 |
|
3/64 |
0.0469 |
1.1906 |
51/64 |
0.7969 |
20.2406 |
|
1/16 |
0.0625 |
1.5875 |
13/16 |
0.8125 |
20.6375 |
|
5/64 |
0.0781 |
1.9844 |
53/64 |
0.8281 |
21.0344 |
|
3/32 |
0.0938 |
2.3813 |
27/32 |
0.8438 |
21.4313 |
|
7/64 |
0.1094 |
2.7781 |
55/64 |
0.8594 |
21.8281 |
|
1/8 |
0.125 |
3.175 |
7/8 |
0.875 |
22.225 |
|
9/64 |
0.1406 |
3.5719 |
57/64 |
0.8906 |
22.6219 |
|
5/32 |
0.1563 |
3.9688 |
29/32 |
0.9063 |
23.0188 |
|
11/64 |
0.1719 |
4.3656 |
59/64 |
0.9219 |
23.4156 |
|
3/16 |
0.1875 |
4.7625 |
15/16 |
0.9375 |
23.8125 |
|
13/64 |
0.2031 |
5.1594 |
61/64 |
0.9531 |
24.2094 |
|
7/32 |
0.2188 |
5.5563 |
31/32 |
0.9688 |
24.6063 |
|
15/64 |
0.2344 |
5.9531 |
63/64 |
0.9844 |
25.0031 |
|
1/4 |
0.25 |
6.35 |
1 |
1 |
25.4 |
|
17/64 |
0.2656 |
6.7469 |
1-1/64 |
1.0156 |
25.7969 |
|
9/32 |
0.2813 |
7.1438 |
1-1/32 |
1.0313 |
26.1938 |
|
19/64 |
0.2969 |
7.5406 |
1-3/64 |
1.0469 |
26.5906 |
|
5/16 |
0.3125 |
7.9375 |
1-1/16 |
1.0625 |
26.9875 |
|
21/64 |
0.3281 |
8.3344 |
1-5/64 |
1.0781 |
27.3844 |
|
11/32 |
0.3438 |
8.7313 |
1-3/32 |
1.0938 |
27.7813 |
|
23/64 |
0.3594 |
9.1281 |
1-7/64 |
1.1094 |
28.1781 |
|
3/8 |
0.375 |
9.525 |
1-1/8 |
1.125 |
28.575 |
|
25/64 |
0.3906 |
9.9219 |
1-9/64 |
1.1406 |
28.9719 |
|
13/32 |
0.4063 |
10.3188 |
1-5/32 |
1.1563 |
29.3688 |
|
27/64 |
0.4219 |
10.7156 |
1-1/64 |
1.1719 |
29.7656 |
|
7/16 |
0.4375 |
11.1125 |
1-3/16 |
1.1875 |
30.1625 |
|
29/64 |
0.4531 |
11.5094 |
1-13/64 |
1.2031 |
30.5594 |
|
15/32 |
0.4688 |
11.9063 |
1-7/32 |
1.2188 |
30.9563 |
|
31/64 |
0.4844 |
12.3031 |
1-15/64 |
1.2344 |
31.3531 |
|
1/2 |
0.5 |
12.7 |
1-1/4 |
1.25 |
31.75 |
|
33/64 |
0.5156 |
13.0969 |
1-17/64 |
1.2656 |
31.1469 |
|
17/32 |
0.5313 |
13.4938 |
1-9/32 |
1.2813 |
32.5438 |
|
35/64 |
0.5469 |
13.8906 |
1-19/64 |
1.2969 |
32.9406 |
|
9/16 |
0.5625 |
14.2875 |
1-5/16 |
1.3125 |
33.3375 |
|
37/64 |
0.5781 |
14.6844 |
1-21/64 |
1.3281 |
33.7344 |
|
19/32 |
0.5938 |
15.0813 |
1-11/32 |
1.3438 |
34.1313 |
|
39/64 |
0.6094 |
15.4781 |
1-23/64 |
1.3594 |
34.5281 |
|
5/8 |
0.625 |
15.875 |
1-3/8 |
1.375 |
34.925 |
|
41/64 |
0.6406 |
16.2719 |
1-25/64 |
1.3906 |
35.3219 |
|
21/32 |
0.6563 |
16.6688 |
1-13/32 |
1.4063 |
35.7188 |
|
43/64 |
0.6719 |
17.0656 |
1-27/64 |
1.4219 |
36.1156 |
|
11/16 |
0.6875 |
17.4625 |
1-7/16 |
1.4375 |
36.5125 |
|
45/64 |
0.7013 |
17.8594 |
1-29/64 |
1.4531 |
36.9094 |
|
23/32 |
0.7188 |
18.2563 |
1-15/32 |
1.4688 |
37.3063 |
|
47/64 |
0.7344 |
18.6531 |
1-31/64 |
1.4844 |
37.7031 |
|
3/4 |
0.75 |
19.05 |
1-1/2 |
1.5 |
38.1 |
Drill Size Chart – Wire Gauge and Letter
Drill Size |
Diameter |
Drill Size |
Diameter |
|||
Inches (in) |
Millimeters (mm) |
Inches (in) |
Millimeters (mm) |
|||
#107 |
0.0019 |
0.0483 |
#40 |
0.0980 |
2.4892 |
|
#106 |
0.0023 |
0.0584 |
#39 |
0.0995 |
2.5273 |
|
#105 |
0.0027 |
0.0686 |
#38 |
0.1015 |
2.5781 |
|
#104 |
0.0031 |
0.0787 |
#37 |
0.1040 |
2.6416 |
|
#103 |
0.0035 |
0.0889 |
#36 |
0.1065 |
2.7051 |
|
#102 |
0.0039 |
0.0991 |
#35 |
0.1100 |
2.7940 |
|
#101 |
0.0043 |
0.1092 |
#34 |
0.1110 |
2.8194 |
|
#100 |
0.0047 |
0.1194 |
#33 |
0.1130 |
2.8702 |
|
#99 |
0.0051 |
0.1295 |
#32 |
0.1160 |
2.9464 |
|
#98 |
0.0055 |
0.1397 |
#31 |
0.1200 |
3.0480 |
|
#97 |
0.0059 |
0.1499 |
#30 |
0.1285 |
3.2639 |
|
#96 |
0.0063 |
0.1600 |
#29 |
0.1360 |
3.4544 |
|
#95 |
0.0067 |
0.1702 |
#28 |
0.1405 |
3.5687 |
|
#94 |
0.0071 |
0.1803 |
#27 |
0.1440 |
3.6576 |
|
#93 |
0.0075 |
0.1905 |
#26 |
0.1470 |
3.7338 |
|
#92 |
0.0079 |
0.2007 |
#25 |
0.1495 |
3.7973 |
|
#91 |
0.0083 |
0.2108 |
#24 |
0.1520 |
3.8608 |
|
#90 |
0.0087 |
0.2210 |
#23 |
0.1540 |
3.9116 |
|
#89 |
0.0091 |
0.2311 |
#22 |
0.1570 |
3.9878 |
|
#88 |
0.0095 |
0.2413 |
#21 |
0.1590 |
4.0386 |
|
#87 |
0.0100 |
0.2540 |
#20 |
0.1610 |
4.0894 |
|
#86 |
0.0105 |
0.2667 |
#19 |
0.1660 |
4.2164 |
|
#85 |
0.0110 |
0.2794 |
#18 |
0.1695 |
4.3053 |
|
#84 |
0.0115 |
0.2921 |
#17 |
0.1730 |
4.3942 |
|
#83 |
0.0120 |
0.3048 |
#16 |
0.1770 |
4.4958 |
|
#82 |
0.0125 |
0.3175 |
#15 |
0.1800 |
4.5720 |
|
#81 |
0.0130 |
0.3302 |
#14 |
0.1820 |
4.6228 |
|
#80 |
0.0135 |
0.3429 |
#13 |
0.1850 |
4.6990 |
|
#79 |
0.0145 |
0.3680 |
#12 |
0.1890 |
4.8006 |
|
#78 |
0.0160 |
0.4064 |
#11 |
0.1910 |
4.8514 |
|
#77 |
0.0180 |
0.4572 |
#10 |
0.1935 |
4.9149 |
|
#76 |
0.0200 |
0.5080 |
#9 |
0.1960 |
4.9784 |
|
#75 |
0.0210 |
0.5334 |
#8 |
0.1990 |
5.0546 |
|
#74 |
0.0225 |
0.5715 |
#7 |
0.2010 |
5.1054 |
|
#73 |
0.0240 |
0.6096 |
#6 |
0.2040 |
5.1816 |
|
#72 |
0.0250 |
0.6350 |
#5 |
0.2055 |
5.2197 |
|
#71 |
0.0260 |
0.6604 |
#4 |
0.2090 |
5.3086 |
|
#70 |
0.0280 |
0.7112 |
#3 |
0.2130 |
5.4102 |
|
#69 |
0.0292 |
0.7417 |
#2 |
0.2210 |
5.6134 |
|
#68 |
0.0310 |
0.7874 |
#1 |
0.2280 |
5.7912 |
|
#67 |
0.0320 |
0.8128 |
A |
0.2340 |
5.9436 |
|
#66 |
0.0330 |
0.8382 |
B |
0.2380 |
6.0452 |
|
#65 |
0.0350 |
0.8890 |
C |
0.2420 |
6.1468 |
|
#64 |
0.0360 |
0.9144 |
D |
0.2460 |
6.2484 |
|
#63 |
0.0370 |
0.9398 |
E |
0.2500 |
6.3500 |
|
#62 |
0.0380 |
0.9652 |
F |
0.2570 |
6.5278 |
|
#61 |
0.0390 |
0.9906 |
G |
0.2610 |
6.6294 |
|
#60 |
0.0400 |
1.0160 |
H |
0.2660 |
6.7564 |
|
#59 |
0.0410 |
1.0414 |
I |
0.2720 |
6.9088 |
|
#58 |
0.0420 |
1.0668 |
J |
0.2770 |
7.0358 |
|
#57 |
0.0430 |
1.0922 |
K |
0.2810 |
7.1374 |
|
#56 |
0.0465 |
1.1811 |
L |
0.2900 |
7.3660 |
|
#55 |
0.0520 |
1.3208 |
M |
0.2950 |
7.4930 |
|
#54 |
0.0550 |
1.3970 |
N |
0.3020 |
7.6708 |
|
#53 |
0.0595 |
1.5113 |
O |
0.3160 |
8.0264 |
|
#52 |
0.0635 |
1.6129 |
P |
0.3230 |
8.2042 |
|
#51 |
0.0670 |
1.7018 |
Q |
0.3320 |
8.4328 |
|
#50 |
0.0700 |
1.7780 |
R |
0.3390 |
8.6106 |
|
#49 |
0.0730 |
1.8542 |
S |
0.3480 |
8.8392 |
|
#48 |
0.0760 |
1.9304 |
T |
0.3580 |
9.0932 |
|
#47 |
0.0785 |
1.9939 |
U |
0.3680 |
9.3472 |
|
#46 |
0.0810 |
2.0574 |
V |
0.3770 |
9.5758 |
|
#45 |
0.0820 |
2.0828 |
W |
0.3860 |
9.8044 |
|
#44 |
0.0860 |
2.1844 |
X |
0.3970 |
10.0838 |
|
#43 |
0.0890 |
2.2606 |
Y |
0.4040 |
10.2616 |
|
#42 |
0.0935 |
2.3749 |
Z |
0.4130 |
10.4902 |
|
#41 |
0.0960 |
2.4384 |
— |
— |
— |
Drill Size Chart – Metric Sizes
Drill Size (mm) |
Diameter |
Drill Size (mm) |
Diameter |
|||
Inches (in) |
Millimeters (mm) |
Inches (in) |
Millimeters (mm) |
|||
0.05 |
0.0020 |
0.05 |
7.9 |
0.3110 |
7.9 |
|
0.1 |
0.0039 |
0.1 |
8 |
0.3150 |
8 |
|
0.2 |
0.0079 |
0.2 |
8.1 |
0.3189 |
8.1 |
|
0.3 |
0.0118 |
0.3 |
8.2 |
0.3228 |
8.2 |
|
0.4 |
0.0158 |
0.4 |
8.3 |
0.3268 |
8.3 |
|
0.5 |
0.0197 |
0.5 |
8.4 |
0.3307 |
8.4 |
|
0.6 |
0.0236 |
0.6 |
8.5 |
0.3347 |
8.5 |
|
0.7 |
0.0276 |
0.7 |
8.6 |
0.3386 |
8.6 |
|
0.8 |
0.0315 |
0.8 |
8.7 |
0.3425 |
8.7 |
|
0.9 |
0.0354 |
0.9 |
8.8 |
0.3465 |
8.8 |
|
1 |
0.0394 |
1 |
8.9 |
0.3504 |
8.9 |
|
1.1 |
0.0433 |
1.1 |
9 |
0.3543 |
9 |
|
1.2 |
0.0472 |
1.2 |
9.1 |
0.3583 |
9.1 |
|
1.3 |
0.0512 |
1.3 |
9.2 |
0.3622 |
9.2 |
|
1.4 |
0.0551 |
1.4 |
9.3 |
0.3661 |
9.3 |
|
1.5 |
0.0591 |
1.5 |
9.4 |
0.3701 |
9.4 |
|
1.6 |
0.0630 |
1.6 |
9.5 |
0.3740 |
9.5 |
|
1.7 |
0.0669 |
1.7 |
9.6 |
0.3780 |
9.6 |
|
1.8 |
0.0709 |
1.8 |
9.7 |
0.3819 |
9.7 |
|
1.9 |
0.0748 |
1.9 |
9.8 |
0.3858 |
9.8 |
|
2 |
0.0787 |
2 |
9.9 |
0.3898 |
9.9 |
|
2.1 |
0.0827 |
2.1 |
10 |
0.3937 |
10 |
|
2.2 |
0.0866 |
2.2 |
10.5 |
0.4134 |
10.5 |
|
2.3 |
0.0906 |
2.3 |
11 |
0.4331 |
11 |
|
2.4 |
0.0945 |
2.4 |
11.5 |
0.4528 |
11.5 |
|
2.5 |
0.0984 |
2.5 |
12 |
0.4724 |
12 |
|
2.6 |
0.1024 |
2.6 |
12.5 |
0.4921 |
12.5 |
|
2.7 |
0.1063 |
2.7 |
13 |
0.5118 |
13 |
|
2.8 |
0.1102 |
2.8 |
13.5 |
0.5315 |
13.5 |
|
2.9 |
0.1142 |
2.9 |
14 |
0.5512 |
14 |
|
3 |
0.1181 |
3 |
14.5 |
0.5709 |
14.5 |
|
3.1 |
0.1221 |
3.1 |
15 |
0.5906 |
15 |
|
3.2 |
0.1260 |
3.2 |
15.5 |
0.6102 |
15.5 |
|
3.3 |
0.1299 |
3.3 |
16 |
0.6299 |
16 |
|
3.4 |
0.1339 |
3.4 |
16.5 |
0.6496 |
16.5 |
|
3.5 |
0.1378 |
3.5 |
17 |
0.6693 |
17 |
|
3.6 |
0.1417 |
3.6 |
17.5 |
0.6890 |
17.5 |
|
3.7 |
0.1457 |
3.7 |
18 |
0.7087 |
18 |
|
3.8 |
0.1496 |
3.8 |
18.5 |
0.7284 |
18.5 |
|
3.9 |
0.1535 |
3.9 |
19 |
0.7480 |
19 |
|
4 |
0.1575 |
4 |
19.5 |
0.7677 |
19.5 |
|
4.1 |
0.1614 |
4.1 |
20 |
0.7874 |
20 |
|
4.2 |
0.1654 |
4.2 |
20.5 |
0.8071 |
20.5 |
|
4.3 |
0.1693 |
4.3 |
21 |
0.8268 |
21 |
|
4.4 |
0.1732 |
4.4 |
21.5 |
0.8465 |
21.5 |
|
4.5 |
0.1772 |
4.5 |
22 |
0.8661 |
22 |
|
4.6 |
0.1811 |
4.6 |
22.5 |
0.8858 |
22.5 |
|
4.7 |
0.1850 |
4.7 |
23 |
0.9055 |
23 |
|
4.8 |
0.1890 |
4.8 |
23.5 |
0.9252 |
23.5 |
|
4.9 |
0.1929 |
4.9 |
24 |
0.9449 |
24 |
|
5 |
0.1969 |
5 |
24.5 |
0.9646 |
24.5 |
|
5.1 |
0.2008 |
5.1 |
25 |
0.9843 |
25 |
|
5.2 |
0.2047 |
5.2 |
25.5 |
1.0039 |
25.5 |
|
5.3 |
0.2087 |
5.3 |
26 |
1.0236 |
26 |
|
5.4 |
0.2126 |
5.4 |
26.5 |
1.0433 |
26.5 |
|
5.5 |
0.2165 |
5.5 |
27 |
1.0630 |
27 |
|
5.6 |
0.2205 |
5.6 |
27.5 |
1.0827 |
27.5 |
|
5.7 |
0.2244 |
5.7 |
28 |
1.1024 |
28 |
|
5.8 |
0.2284 |
5.8 |
28.5 |
1.1221 |
28.5 |
|
5.9 |
0.2323 |
5.9 |
29 |
1.1417 |
29 |
|
6 |
0.2362 |
6 |
29.5 |
1.1614 |
29.5 |
|
6.1 |
0.2402 |
6.1 |
30 |
1.1811 |
30 |
|
6.2 |
0.2441 |
6.2 |
30.5 |
1.2008 |
30.5 |
|
6.3 |
0.2480 |
6.3 |
31 |
1.2205 |
31 |
|
6.4 |
0.2520 |
6.4 |
31 |
1.2402 |
31 |
|
6.5 |
0.2559 |
6.5 |
32 |
1.2598 |
32 |
|
6.6 |
0.2598 |
6.6 |
32 |
1.2795 |
32 |
|
6.7 |
0.2638 |
6.7 |
33 |
1.2992 |
33 |
|
6.8 |
0.2677 |
6.8 |
33 |
1.3189 |
33 |
|
6.9 |
0.2717 |
6.9 |
34 |
1.3386 |
34 |
|
7 |
0.2756 |
7 |
34 |
1.3583 |
34 |
|
7.1 |
0.2795 |
7.1 |
35 |
1.3780 |
35 |
|
7.2 |
0.2835 |
7.2 |
35 |
1.3976 |
35 |
|
7.3 |
0.2874 |
7.3 |
36 |
1.4173 |
36 |
|
7.4 |
0.2913 |
7.4 |
36 |
1.4370 |
36 |
|
7.5 |
0.2953 |
7.5 |
37 |
1.4567 |
37 |
|
7.6 |
0.2992 |
7.6 |
37 |
1.4764 |
37 |
|
7.7 |
0.3032 |
7.7 |
38 |
1.4961 |
38 |
|
7.8 |
0.3071 |
7.8 |
— |
— |
— |
Tap Drill Chart (mm and inches)
TAP SIZE |
CUTTING TAPS |
TRU-FLO ™ FORMING TAPS |
|||
INCH |
METRIC |
DRILL SIZE |
DECIMAL |
DRILL SIZE |
DECIMAL |
0-80 |
3/64 |
.0469 |
54 |
.0550 |
|
M1.6 X 0.35 |
1.25mm |
.0492 |
1.45mm |
.0571 |
|
M1.8 X 0.35 |
1.45mm |
.0571 |
1.65mm |
.0650 |
|
1-64 |
53 |
.0595 |
51 |
.0650 |
|
1-72 |
53 |
.0595 |
51 |
.0650 |
|
M2 X 0.40 |
1.60mm |
.0630 |
1.80mm |
.0709 |
|
2-56 |
50 |
.0700 |
5/64 |
.0781 |
|
2-64 |
50 |
.0700 |
47 |
.0785 |
|
M2.2 X 0.45 |
1.75mm |
.0689 |
2.00mm |
.0787 |
|
M2.5 X 0.45 |
2.05mm |
.0807 |
2.30mm |
.0906 |
|
3-48 |
47 |
.0785 |
43 |
.0890 |
|
3-56 |
46 |
.0810 |
2.30mm |
.0905 |
|
4-40 |
43 |
.0890 |
38 |
.1015 |
|
4-48 |
42 |
.0935 |
2.60mm |
.1024 |
|
M3 X 0.50 |
2.50mm |
.0984 |
7/64 |
.1094 |
|
5-40 |
38 |
.1015 |
33 |
.1130 |
|
5-44 |
37 |
.1040 |
2.90mm |
.1142 |
|
M3.5 X 0.60 |
2.90mm |
.1142 |
3.20mm |
.1260 |
|
6-32 |
36 |
.1065 |
1/8 |
.1250 |
|
6-40 |
33 |
.1130 |
3.25mm |
.1280 |
|
M4 X 0.70 |
3.30mm |
.1299 |
3.70mm |
.1457 |
|
8-32 |
29 |
.1360 |
25 |
.1495 |
|
8-36 |
29 |
.1360 |
24 |
.1520 |
|
M4.5 X 0.75 |
3.70mm |
.1476 |
4.10mm |
.1614 |
|
10-24 |
26 |
.1470 |
11/64 |
.1719 |
|
10-32 |
21 |
.1590 |
16 |
.1770 |
|
M5 X 0.80 |
4.20mm |
.1654 |
14 |
.1820 |
|
12-24 |
16 |
.1770 |
5mm |
.1969 |
|
12-28 |
15 |
.1800 |
7 |
.2010 |
|
M6 X 1.00 |
5.00mm |
.1969 |
7/32 |
.2188 |
|
1/4-20 |
7 |
.2010 |
1 |
.2280 |
|
1/4-28 |
3 |
.2130 |
15/64 |
.2340 |
|
M7 X 1.00 |
6.00mm |
.2362 |
F |
.2570 |
|
5/16-18 |
F |
.2570 |
L |
.2900 |
|
5/16-24 |
I |
.2720 |
M |
.2950 |
|
M8 X 1.25 |
6.70mm |
.2638 |
7.40mm |
.2913 |
|
M8 X 1.0 |
7.00mm |
.2756 |
19/64 |
.2969 |
|
3/8-16 |
5/16 |
.3125 |
S |
.3480 |
|
3/8-24 |
Q |
.3320 |
T |
.3580 |
|
M10 X 1.50 |
8.50mm |
.3346 |
U |
.3680 |
|
M10 X 1.25 |
8.70mm |
.3425 |
9.40mm |
.3701 |
|
7/16-14 |
U |
.3680 |
Y |
.4040 |
|
7/16-20 |
25/64 |
.3906 |
Z |
.4130 |
|
M12 X 1.75 |
10.20mm |
.4016 |
11.20mm |
.4409 |
|
M12 X 1.25 |
10.80mm |
.4252 |
11.50mm |
.4528 |
|
1/2-13 |
27/64 |
.4219 |
15/32 |
.4682 |
|
1/2-20 |
29/64 |
.4531 |
12.25mm |
.4823 |
|
M14 X 2.00 |
12.00mm |
.4224 |
33/64 |
.5156 |
|
9/16-12 |
31/64 |
.4844 |
17/32 |
.5312 |
|
9/16-18 |
33/64 |
.5156 |
13.50mm |
.5315 |
|
5/8-11 |
17/32 |
.5312 |
14.75mm |
.5807 |
|
5/8-18 |
37/64 |
.5781 |
15.25mm |
.6004 |
|
M16 X 2.00 |
14.00mm |
.5512 |
19/32 |
.5938 |
|
M16 X 1.50 |
14.50mm |
.5906 |
15.25mm |
.6004 |
|
M18 X 2.50 |
15.50mm |
.6102 |
39/64 |
.6094 |
|
M18 X 1.50 |
16.50mm |
.6496 |
17.25mm |
.6791 |
|
3/4-10 |
21/32 |
0.6562 |
45/64 |
0.7031 |
|
3/4-16 |
11/16 |
0.6875 |
23/32 |
0.7188 |
|
M20 X 2.50 |
17.50mm |
0.689 |
|||
M20 X 1.50 |
18.50mm |
0.7283 |
|||
M22 X 2.50 |
19.50mm |
0.7677 |
|||
M22 X 1.50 |
20.50mm |
0.8071 |
|||
7/8-9 |
49/64 |
0.7656 |
|||
7/8-14 |
13/16 |
0.8125 |
|||
M24 X 3.00 |
21.00mm |
0.8268 |
|||
M24 X 2.00 |
22.00mm |
0.8661 |
|||
1-8 |
7/8 |
0.875 |
|||
1-12 |
59/64 |
0.9219 |
|||
M27 X 3.00 |
24.00mm |
0.9449 |
|||
M27 X 2.00 |
25.00mm |
0.9843 |
|||
1-1/8-7 |
63/64 |
0.9844 |
|||
1-1/8-12 |
1-3/64 |
1.0469 |
|||
M30 X 3.50 |
26.50mm |
1.0433 |
|||
M30 X 2.00 |
28.00mm |
1.1024 |
|||
1-1/4-7 |
1-7/64 |
1.1094 |
|||
1-1/4-12 |
1-11/64 |
1.1719 |
|||
M33 X 3.50 |
29.50mm |
1.1614 |
|||
M33 X 2.00 |
31.00mm |
1.2205 |
|||
1-3/8-6 |
1-7/32 |
1.2188 |
|||
1-3/8-12 |
1-19/64 |
1.2969 |
|||
M36 X 4.00 |
32.00mm |
1.2598 |
|||
M36 X 3.00 |
33.00mm |
1.2992 |
|||
1-1/2-6 |
1-11/32 |
1.3438 |
|||
1-1/2-12 |
1-27/64 |
1.4219 |
|||
M39 X 4.00 |
35.00mm |
1.378 |
|||
M39 X 3.00 |
36.00mm |
1.4173 |
|
Pipe Thread Drilled Hole Sizes
NOMINAL SIZE |
NPT |
NPTF |
NPSC |
NPSM |
NPSF |
NPSI |
BSPT |
BSPP |
1/16 – 27 |
D (0.246) |
D (0.246) |
0.25 |
0.25 |
0.25 |
|||
1/8 – 27 |
Q (0.332) |
Q (0.332) |
0.3437 |
0.3593 |
0.3437 |
0.3437 |
||
1/8 – 28 |
0.3281 |
0.3437 |
||||||
1/4 – 18 |
0.4375 |
0.4375 |
0.4375 |
0.4687 |
0.4375 |
0.4375 |
||
1/4 – 19 |
0.4375 |
0.4531 |
||||||
3/8 – 18 |
0.5625 |
0.5781 |
0.5781 |
0.6093 |
0.5781 |
0.5781 |
||
3/8 – 19 |
0.5781 |
0.5937 |
||||||
1/2 – 14 |
0.7031 |
0.7031 |
0.7187 |
0.75 |
0.7187 |
0.7187 |
0.7187 |
0.7343 |
5/8 – 14 |
0.8125 |
|||||||
3/4 – 14 |
0.9062 |
0.9218 |
0.9218 |
0.9646 |
0.938 |
0.965 |
||
7/8 – 14 |
1.1093 |
|||||||
1 – 11 |
1.1718 |
1.1875 |
||||||
1 – 11-1/2 |
1.1406 |
1.1562 |
1.1562 |
1.2031 |
||||
1-1/4 – 11 |
1.5 |
1.5468 |
||||||
1-1/4 – 11-1/2 |
1.4843 |
1.5 |
1.5 |
1.5468 |
||||
1-1/2 – 11 |
1.75 |
1.7656 |
||||||
1-1/2 – 11-1/2 |
1.7343 |
1.7343 |
1.75 |
1.7913 |
||||
1-3/4 – 11 |
2 |
|||||||
2 – 11 |
2.2187 |
2.25 |
||||||
2 – 11-1/2 |
2.2031 |
2.2187 |
2.2187 |
2.2638 |
Tap Drill Size Chart For Standard Threads, Tap Drill Size Chart mm
Tap Size |
Drill Size |
M1 x 0.25 |
0.75mm |
M1.1 x 0.25 |
0.85mm |
M1.2 x 0.25 |
0.95mm |
M1.4 x 0.30 |
1.10mm |
M1.6 x 0.35 |
1.25mm |
M1.8 x 0.35 |
1.45mm |
M2 x 0.4 |
1.60mm |
M2.2 x 0.45 |
1.75mm |
M2.5 x 0.45 |
2.05mm |
M3 x 0.5 |
2.50mm |
M3.5 x 0.6 |
2.90mm |
M4 x 0.7 |
3.30mm |
M4.5 x 0.75 |
3.70mm |
M5 x 0.8 |
4.20mm |
M6 x 1 |
5.00mm |
M7 x 1 |
6.00mm |
M8 x 1.25 |
6.80mm |
M9 x 1.25 |
7.80mm |
M10 x 1.5 |
8.50mm |
M11 x 1.5 |
9.50mm |
M12 x 1.75 |
10.20mm |
M14 x 2 |
12.00mm |
M16 x 2 |
14.00mm |
M18 x 2.5 |
15.50mm |
M20 x 2.5 |
17.50mm |
M22 x 2.5 |
19.50mm |
M24 x 3 |
21.00mm |
M27 x 3 |
24.00mm |
M30 x 3.5 |
26.50mm |
M33 x 3.5 |
29.50mm |
M36 x 4 |
32.00mm |
M39 x 4 |
35.00mm |
M42 x 4.5 |
37.50mm |
M45 x 4.5 |
40.50mm |
M48 x 5 |
43.00mm |
M52 x 5 |
47.00mm |
M56 x 5.5 |
50.50mm |
M60 x 5.5 |
54.50mm |
M64 x 6 |
58.00mm |
ANSI Drill Size Chart – ISO Metric Drill Bit Size Table.
ANSI Size Drill Bit Chart |
ISO (Metric Size Drills) & Conversion to Inches |
|||||||||||
Drill |
Decimal |
Drill |
Decimal |
Drill |
Decimal |
Drill |
Decimal |
Drill |
Decimal |
Drill |
Decimal |
|
80 |
.0135 |
1/8 |
.1250 |
O |
.3160 |
.35 |
.0138 |
3.4 |
.1339 |
8.0 |
.3150 |
|
79 |
.0145 |
30 |
.1285 |
P |
.3230 |
.4 |
.0157 |
3.5 |
.1378 |
8.1 |
.3189 |
|
1/64 |
.0156 |
29 |
.1360 |
21/64 |
.3281 |
.45 |
.0177 |
3.6 |
.1417 |
8.2 |
.3228 |
|
78 |
.0160 |
28 |
.1405 |
Q |
.3320 |
.5 |
.0197 |
3.7 |
.1457 |
8.25 |
.3248 |
|
77 |
.0180 |
9/64 |
.1406 |
R |
.3390 |
.55 |
.0217 |
3.75 |
.1477 |
8.3 |
.3267 |
|
76 |
.0200 |
27 |
.1440 |
11/32 |
.3437 |
.6 |
.0236 |
3.8 |
.1496 |
8.4 |
.3307 |
|
75 |
.0210 |
26 |
.1470 |
S |
.3480 |
.65 |
.0256 |
3.9 |
.1535 |
8.5 |
.3346 |
|
74 |
.0225 |
25 |
.1495 |
T |
.3580 |
.7 |
.0276 |
4.0 |
.1575 |
8.6 |
.3386 |
|
73 |
.0240 |
24 |
.1520 |
23/64 |
.3594 |
.75 |
.0295 |
4.1 |
.1614 |
8.7 |
.3425 |
|
72 |
.0250 |
23 |
.1540 |
U |
.3680 |
.8 |
.0315 |
4.2 |
.1654 |
8.75 |
.3445 |
|
71 |
.0260 |
5/32 |
.1562 |
3/8 |
.3750 |
.85 |
.0335 |
4.25 |
.1674 |
8.8 |
.3465 |
|
70 |
.0280 |
22 |
.1570 |
V |
.3770 |
.9 |
.0355 |
4.3 |
.1693 |
8.9 |
.3504 |
|
69 |
.0292 |
21 |
.1590 |
W |
.3860 |
.95 |
.0374 |
4.4 |
.1732 |
9.0 |
.3543 |
|
68 |
.0310 |
20 |
.1610 |
25/64 |
.3906 |
1.0 |
.0394 |
4.5 |
.1771 |
9.1 |
.3583 |
|
1/32 |
.0313 |
19 |
.1660 |
X |
.3970 |
1.05 |
.0413 |
4.6 |
.1811 |
9.2 |
.3622 |
|
67 |
.0320 |
18 |
.1695 |
Y |
.4040 |
1.1 |
.0433 |
4.7 |
.1850 |
9.25 |
.3642 |
|
66 |
.0330 |
11/64 |
.1719 |
13/32 |
.4062 |
1.15 |
.0453 |
4.75 |
.1870 |
9.35 |
.3661 |
|
65 |
.0350 |
17 |
.1730 |
Z |
.4130 |
1.2 |
.0472 |
4.8 |
.1890 |
9.4 |
.3701 |
|
64 |
.0360 |
16 |
.1770 |
27/64 |
.4219 |
1.25 |
.0492 |
4.9 |
.1929 |
9.5 |
.3740 |
|
63 |
.0370 |
15 |
.1800 |
7/16 |
.4375 |
1.3 |
.0512 |
5.0 |
.1968 |
9.6 |
.3780 |
|
62 |
.0380 |
14 |
.1820 |
29/64 |
.4531 |
1.35 |
.0531 |
5.1 |
.2008 |
9.7 |
.3819 |
|
61 |
.0390 |
13 |
.1850 |
15/32 |
.4687 |
1.4 |
.0551 |
5.2 |
.2047 |
9.75 |
.3839 |
|
60 |
.0400 |
3/16 |
.1875 |
31/64 |
.4844 |
1.45 |
.0571 |
5.25 |
.2067 |
9.8 |
.3858 |
|
59 |
.0410 |
12 |
.1890 |
1/2 |
.5000 |
1.5 |
.0591 |
5.3 |
.2087 |
9.9 |
.3898 |
|
58 |
.0420 |
11 |
.1910 |
33/64 |
.5156 |
1.55 |
.0610 |
5.4 |
.2126 |
10.0 |
.3937 |
|
57 |
.0430 |
10 |
.1935 |
17/32 |
.5312 |
1.6 |
.0629 |
5.5 |
.2165 |
10.5 |
.4133 |
|
56 |
.0465 |
9 |
.1960 |
35/64 |
.5469 |
1.65 |
.0650 |
5.6 |
.2205 |
11.0 |
.4331 |
|
3/64 |
.0469 |
8 |
.1990 |
9/16 |
.5625 |
1.7 |
.0669 |
5.7 |
.2244 |
11.5 |
.4528 |
|
55 |
.0520 |
7 |
.2010 |
37/64 |
.5781 |
1.75 |
.0689 |
5.75 |
.2264 |
12.0 |
.4724 |
|
54 |
.0550 |
13/64 |
.2031 |
19/32 |
.5937 |
1.8 |
.0709 |
5.8 |
.2283 |
12.5 |
.4921 |
|
53 |
.0595 |
6 |
.2040 |
39/64 |
.6094 |
1.85 |
.0728 |
5.9 |
.2323 |
13.0 |
.5118 |
|
1/16 |
.0625 |
5 |
.2055 |
5/8 |
.6250 |
1.9 |
.0748 |
6.0 |
.2362 |
13.5 |
.5315 |
|
52 |
.0635 |
4 |
.2090 |
41/64 |
.6406 |
1.95 |
.0768 |
6.1 |
.2401 |
14.0 |
.5512 |
|
51 |
.0670 |
3 |
.2130 |
21/32 |
.6562 |
2.0 |
.0787 |
6.2 |
.2441 |
14.5 |
.5708 |
|
50 |
.0700 |
7/32 |
.2187 |
43/64 |
.6719 |
2.05 |
.0807 |
6.25 |
.2461 |
15.0 |
.5906 |
|
49 |
.0730 |
2 |
.2210 |
11/16 |
.6875 |
2.1 |
.0827 |
6.3 |
.2480 |
15.5 |
.6102 |
|
48 |
.0760 |
1 |
.2280 |
45/64 |
.7031 |
2.15 |
.0846 |
6.4 |
.2520 |
16.0 |
.6300 |
|
5/64 |
.0781 |
A |
.2340 |
23/32 |
.7187 |
2.2 |
.0866 |
6.5 |
.2559 |
16.5 |
.6496 |
|
47 |
.0785 |
15/64 |
.2344 |
47/64 |
.7344 |
2.25 |
.0886 |
6.6 |
.2598 |
17.0 |
.6693 |
|
46 |
.0810 |
B |
.2380 |
3/4 |
.7500 |
2.3 |
.0905 |
6.7 |
.2638 |
17.5 |
.6889 |
|
45 |
.0820 |
C |
.2420 |
49/64 |
.7656 |
2.35 |
.0925 |
6.75 |
.2658 |
18.0 |
.7087 |
|
44 |
.0860 |
D |
.2460 |
25/32 |
.7812 |
2.4 |
.0945 |
6.8 |
.2677 |
18.5 |
.7283 |
|
43 |
.0890 |
E |
.2500 |
51/64 |
.7969 |
2.45 |
.0965 |
6.9 |
.2716 |
19.0 |
.7480 |
|
42 |
.0935 |
1/4 |
.2500 |