For any project involving a drill (and, therefore, drill bits), selecting the bit size that matches the screw size is always crucial. If you choose the wrong size, the pilot hole you’re working with won’t match the screw.
If the pilot hole is too big, the screw won’t stay in; if it’s too small, the screw won’t fit, and you may even inadvertently strip the material. Neither situation is a good one. Of course, choosing the right size makes your job easy and enables it to flow well from step to step.
The critical information you need to know for this article is that you need 7/64-inch and 1/8-inch drill bits for softwood and hardwood, respectively.
Factors to Consider When Selecting the Right Drill Bit Size
You need to consider several factors when selecting the right drill bit size for your project. These include:
- Type of material being drilled: Wood is the most common for household jobs, but you also have metal, tile, porcelain, concrete, and plastic.
- Length of the screw
- Pilot hole size requirements: The hole size should be the same as or shorter than the screw’s center core diameter.
- Screw diameter and thread count
Practical Tips for Selecting the Right Drill Bit Size
Now that you know the factors you need to consider to select the correct drill bit size, it’s time to review what you need to do when selecting your bits.
- First, test-fit the screw.
- Measure the screw thread count and diameter.
- Align the size of the drill bit with the type of material. Hardwood may need a slightly smaller bit size.
Here are some guidelines for drill bit types and the materials they align with:
- For metal, you want HSS twist bits.
- For masonry projects, you want twist bits with a carbide fin.
- You want a simple twist drill bit for wood, sometimes with a brad point.
Drill Bit Size Charts
For your reference, we’ve included the following exhaustive drill bit size chart. Visit Ecenrode Welds today for all of your drilling needs!
|
Drill size |
Diameter (in) |
Diameter (mm) |
|
#107 |
0.0019 |
0.0483 |
|
0.05 mm |
0.0020 |
0.0500 |
|
#106 |
0.0023 |
0.0584 |
|
#105 |
0.0027 |
0.0686 |
|
#104 |
0.0031 |
0.0787 |
|
#103 |
0.0035 |
0.0889 |
|
#102 |
0.0039 |
0.0991 |
|
0.1 mm |
0.0039 |
0.1000 |
|
#101 |
0.0043 |
0.1092 |
|
#100 |
0.0047 |
0.1194 |
|
#99 |
0.0051 |
0.1295 |
|
#98 |
0.0055 |
0.1397 |
|
#97 |
0.0059 |
0.1499 |
|
#96 |
0.0063 |
0.1600 |
|
#95 |
0.0067 |
0.1702 |
|
#94 |
0.0071 |
0.1803 |
|
#93 |
0.0075 |
0.1905 |
|
0.2 mm |
0.0079 |
0.2000 |
|
#92 |
0.0079 |
0.2007 |
|
#91 |
0.0083 |
0.2108 |
|
#90 |
0.0087 |
0.2210 |
|
#89 |
0.0091 |
0.2311 |
|
#88 |
0.0095 |
0.2413 |
|
#87 |
0.0100 |
0.2540 |
|
#86 |
0.0105 |
0.2667 |
|
#85 |
0.0110 |
0.2794 |
|
#84 |
0.0115 |
0.2921 |
|
0.3 mm |
0.0118 |
0.3000 |
|
#83 |
0.0120 |
0.3048 |
|
#82 |
0.0125 |
0.3175 |
|
#81 |
0.0130 |
0.3302 |
|
#80 |
0.0135 |
0.3429 |
|
#79 |
0.0145 |
0.3680 |
|
1/64 in |
0.0156 |
0.3969 |
|
0.4 mm |
0.0158 |
0.4000 |
|
#78 |
0.0160 |
0.4064 |
|
#77 |
0.0180 |
0.4572 |
|
0.5 mm |
0.0197 |
0.5000 |
|
#76 |
0.0200 |
0.5080 |
|
#75 |
0.0210 |
0.5334 |
|
#74 |
0.0225 |
0.5715 |
|
0.6 mm |
0.0236 |
0.6000 |
|
#73 |
0.0240 |
0.6096 |
|
#72 |
0.0250 |
0.6350 |
|
#71 |
0.0260 |
0.6604 |
|
0.7 mm |
0.0276 |
0.7000 |
|
#70 |
0.0280 |
0.7112 |
|
#69 |
0.0292 |
0.7417 |
|
#68 |
0.0310 |
0.7874 |
|
1/32 in |
0.0313 |
0.7938 |
|
0.8 mm |
0.0315 |
0.8000 |
|
#67 |
0.0320 |
0.8128 |
|
#66 |
0.0330 |
0.8382 |
|
#65 |
0.0350 |
0.8890 |
|
0.9 mm |
0.0354 |
0.9000 |
|
#64 |
0.0360 |
0.9144 |
|
#63 |
0.0370 |
0.9398 |
|
#62 |
0.0380 |
0.9652 |
|
#61 |
0.0390 |
0.9906 |
|
1 mm |
0.0394 |
1.0000 |
|
#60 |
0.0400 |
1.0160 |
|
#59 |
0.0410 |
1.0414 |
|
#58 |
0.0420 |
1.0668 |
|
#57 |
0.0430 |
1.0922 |
|
1.1 mm |
0.0433 |
1.1000 |
|
#56 |
0.0465 |
1.1811 |
|
3/64 in |
0.0469 |
1.1906 |
|
1.2 mm |
0.0472 |
1.2000 |
|
1.3 mm |
0.0512 |
1.3000 |
|
#55 |
0.0520 |
1.3208 |
|
#54 |
0.0550 |
1.3970 |
|
1.4 mm |
0.0551 |
1.4000 |
|
1.5 mm |
0.0591 |
1.5000 |
|
#53 |
0.0595 |
1.5113 |
|
1/16 in |
0.0625 |
1.5875 |
|
1.6 mm |
0.0630 |
1.6000 |
|
#52 |
0.0635 |
1.6129 |
|
1.7 mm |
0.0669 |
1.7000 |
|
#51 |
0.0670 |
1.7018 |
|
#50 |
0.0700 |
1.7780 |
|
1.8 mm |
0.0709 |
1.8000 |
|
#49 |
0.0730 |
1.8542 |
|
1.9 mm |
0.0748 |
1.9000 |
|
#48 |
0.0760 |
1.9304 |
|
5/64 in |
0.0781 |
1.9844 |
|
#47 |
0.0785 |
1.9939 |
|
2 mm |
0.0787 |
2.0000 |
|
#46 |
0.0810 |
2.0574 |
|
#45 |
0.0820 |
2.0828 |
|
2.1 mm |
0.0827 |
2.1000 |
|
#44 |
0.0860 |
2.1844 |
|
2.2 mm |
0.0866 |
2.2000 |
|
#43 |
0.0890 |
2.2606 |
|
2.3 mm |
0.0906 |
2.3000 |
|
#42 |
0.0935 |
2.3749 |
|
3/32 in |
0.0938 |
2.3813 |
|
2.4 mm |
0.0945 |
2.4000 |
|
#41 |
0.0960 |
2.4384 |
|
#40 |
0.0980 |
2.4892 |
|
2.5 mm |
0.0984 |
2.5000 |
|
#39 |
0.0995 |
2.5273 |
|
#38 |
0.1015 |
2.5781 |
|
2.6 mm |
0.1024 |
2.6000 |
|
#37 |
0.1040 |
2.6416 |
|
2.7 mm |
0.1063 |
2.7000 |
|
#36 |
0.1065 |
2.7051 |
|
7/64 in |
0.1094 |
2.7781 |
|
#35 |
0.1100 |
2.7940 |
|
2.8 mm |
0.1102 |
2.8000 |
|
#34 |
0.1110 |
2.8194 |
|
#33 |
0.1130 |
2.8702 |
|
2.9 mm |
0.1142 |
2.9000 |
|
#32 |
0.1160 |
2.9464 |
|
3 mm |
0.1181 |
3.0000 |
|
#31 |
0.1200 |
3.0480 |
|
3.1 mm |
0.1221 |
3.1000 |
|
1/8 in |
0.1250 |
3.1750 |
|
3.2 mm |
0.1260 |
3.2000 |
|
#30 |
0.1285 |
3.2639 |
|
3.3 mm |
0.1299 |
3.3000 |
|
3.4 mm |
0.1339 |
3.4000 |
|
#29 |
0.1360 |
3.4544 |
|
3.5 mm |
0.1378 |
3.5000 |
|
#28 |
0.1405 |
3.5687 |
|
9/64 in |
0.1406 |
3.5719 |
|
3.6 mm |
0.1417 |
3.6000 |
|
#27 |
0.1440 |
3.6576 |
|
3.7 mm |
0.1457 |
3.7000 |
|
#26 |
0.1470 |
3.7338 |
|
#25 |
0.1495 |
3.7973 |
|
3.8 mm |
0.1496 |
3.8000 |
|
#24 |
0.1520 |
3.8608 |
|
3.9 mm |
0.1535 |
3.9000 |
|
#23 |
0.1540 |
3.9116 |
|
5/32 in |
0.1563 |
3.9688 |
|
#22 |
0.1570 |
3.9878 |
|
4 mm |
0.1575 |
4.0000 |
|
#21 |
0.1590 |
4.0386 |
|
#20 |
0.1610 |
4.0894 |
|
4.1 mm |
0.1614 |
4.1000 |
|
4.2 mm |
0.1654 |
4.2000 |
|
#19 |
0.1660 |
4.2164 |
|
4.3 mm |
0.1693 |
4.3000 |
|
#18 |
0.1695 |
4.3053 |
|
11/64 in |
0.1719 |
4.3656 |
|
#17 |
0.1730 |
4.3942 |
|
4.4 mm |
0.1732 |
4.4000 |
|
#16 |
0.1770 |
4.4958 |
|
4.5 mm |
0.1772 |
4.5000 |
|
#15 |
0.1800 |
4.5720 |
|
4.6 mm |
0.1811 |
4.6000 |
|
#14 |
0.1820 |
4.6228 |
|
#13 |
0.1850 |
4.6990 |
|
4.7 mm |
0.1850 |
4.7000 |
|
3/16 in |
0.1875 |
4.7625 |
|
4.8 mm |
0.1890 |
4.8000 |
|
#12 |
0.1890 |
4.8006 |
|
#11 |
0.1910 |
4.8514 |
|
4.9 mm |
0.1929 |
4.9000 |
|
#10 |
0.1935 |
4.9149 |
|
#9 |
0.1960 |
4.9784 |
|
5 mm |
0.1969 |
5.0000 |
|
#8 |
0.1990 |
5.0546 |
|
5.1 mm |
0.2008 |
5.1000 |
|
#7 |
0.2010 |
5.1054 |
|
13/64 in |
0.2031 |
5.1594 |
|
#6 |
0.2040 |
5.1816 |
|
5.2 mm |
0.2047 |
5.2000 |
|
#5 |
0.2055 |
5.2197 |
|
5.3 mm |
0.2087 |
5.3000 |
|
#4 |
0.2090 |
5.3086 |
|
5.4 mm |
0.2126 |
5.4000 |
|
#3 |
0.2130 |
5.4102 |
|
5.5 mm |
0.2165 |
5.5000 |
|
7/32 in |
0.2188 |
5.5563 |
|
5.6 mm |
0.2205 |
5.6000 |
|
#2 |
0.2210 |
5.6134 |
|
5.7 mm |
0.2244 |
5.7000 |
|
#1 |
0.2280 |
5.7912 |
|
5.8 mm |
0.2284 |
5.8000 |
|
5.9 mm |
0.2323 |
5.9000 |
|
A |
0.2340 |
5.9436 |
|
15/64 in |
0.2344 |
5.9531 |
|
6 mm |
0.2362 |
6.0000 |
|
B |
0.2380 |
6.0452 |
|
6.1 mm |
0.2402 |
6.1000 |
|
C |
0.2420 |
6.1468 |
|
6.2 mm |
0.2441 |
6.2000 |
|
D |
0.2460 |
6.2484 |
|
6.3 mm |
0.2480 |
6.3000 |
|
1/4 in |
0.2500 |
6.3500 |
|
E |
0.2500 |
6.3500 |
|
6.4 mm |
0.2520 |
6.4000 |
|
6.5 mm |
0.2559 |
6.5000 |
|
F |
0.2570 |
6.5278 |
|
6.6 mm |
0.2598 |
6.6000 |
|
G |
0.2610 |
6.6294 |
|
6.7 mm |
0.2638 |
6.7000 |
|
17/64 in |
0.2656 |
6.7469 |
|
H |
0.2660 |
6.7564 |
|
6.8 mm |
0.2677 |
6.8000 |
|
6.9 mm |
0.2717 |
6.9000 |
|
I |
0.2720 |
6.9088 |
|
7 mm |
0.2756 |
7.0000 |
|
J |
0.2770 |
7.0358 |
|
7.1 mm |
0.2795 |
7.1000 |
|
K |
0.2810 |
7.1374 |
|
9/32 in |
0.2813 |
7.1438 |
|
7.2 mm |
0.2835 |
7.2000 |
|
7.3 mm |
0.2874 |
7.3000 |
|
L |
0.2900 |
7.3660 |
|
7.4 mm |
0.2913 |
7.4000 |
|
M |
0.2950 |
7.4930 |
|
7.5 mm |
0.2953 |
7.5000 |
|
19/64 in |
0.2969 |
7.5406 |
|
7.6 mm |
0.2992 |
7.6000 |
|
N |
0.3020 |
7.6708 |
|
7.7 mm |
0.3032 |
7.7000 |
|
7.8 mm |
0.3071 |
7.8000 |
|
7.9 mm |
0.3110 |
7.9000 |
|
5/16 in |
0.3125 |
7.9375 |
|
8 mm |
0.3150 |
8.0000 |
|
O |
0.3160 |
8.0264 |
|
8.1 mm |
0.3189 |
8.1000 |
|
8.2 mm |
0.3228 |
8.2000 |
|
P |
0.3230 |
8.2042 |
|
8.3 mm |
0.3268 |
8.3000 |
|
21/64 in |
0.3281 |
8.3344 |
|
8.4 mm |
0.3307 |
8.4000 |
|
Q |
0.3320 |
8.4328 |
|
8.5 mm |
0.3347 |
8.5000 |
|
8.6 mm |
0.3386 |
8.6000 |
|
R |
0.3390 |
8.6106 |
|
8.7 mm |
0.3425 |
8.7000 |
|
11/32 in |
0.3438 |
8.7313 |
|
8.8 mm |
0.3465 |
8.8000 |
|
S |
0.3480 |
8.8392 |
|
8.9 mm |
0.3504 |
8.9000 |
|
9 mm |
0.3543 |
9.0000 |
|
T |
0.3580 |
9.0932 |
|
9.1 mm |
0.3583 |
9.1000 |
|
23/64 in |
0.3594 |
9.1281 |
|
9.2 mm |
0.3622 |
9.2000 |
|
9.3 mm |
0.3661 |
9.3000 |
|
U |
0.3680 |
9.3472 |
|
9.4 mm |
0.3701 |
9.4000 |
|
9.5 mm |
0.3740 |
9.5000 |
|
3/8 in |
0.3750 |
9.5250 |
|
V |
0.3770 |
9.5758 |
|
9.6 mm |
0.3780 |
9.6000 |
|
9.7 mm |
0.3819 |
9.7000 |
|
9.8 mm |
0.3858 |
9.8000 |
|
W |
0.3860 |
9.8044 |
|
9.9 mm |
0.3898 |
9.9000 |
|
25/64 in |
0.3906 |
9.9219 |
|
10 mm |
0.3937 |
10.0000 |
|
X |
0.3970 |
10.0838 |
|
Y |
0.4040 |
10.2616 |
|
13/32 in |
0.4063 |
10.3188 |
|
Z |
0.4130 |
10.4902 |
|
10.5 mm |
0.4134 |
10.5000 |
|
27/64 in |
0.4219 |
10.7156 |
|
11 mm |
0.4331 |
11.0000 |
|
7/16 in |
0.4375 |
11.1125 |
|
11.5 mm |
0.4528 |
11.5000 |
|
29/64 in |
0.4531 |
11.5094 |
|
15/32 in |
0.4688 |
11.9063 |
|
12 mm |
0.4724 |
12.0000 |
|
31/64 in |
0.4844 |
12.3031 |
|
12.5 mm |
0.4921 |
12.5000 |
|
1/2 in |
0.5000 |
12.7000 |
|
13 mm |
0.5118 |
13.0000 |
|
33/64 in |
0.5156 |
13.0969 |
|
17/32 in |
0.5313 |
13.4938 |
|
13.5 mm |
0.5315 |
13.5000 |
|
35/64 in |
0.5469 |
13.8906 |
|
14 mm |
0.5512 |
14.0000 |
|
9/16 in |
0.5625 |
14.2875 |
|
14.5 mm |
0.5709 |
14.5000 |
|
37/64 in |
0.5781 |
14.6844 |
|
15 mm |
0.5906 |
15.0000 |
|
19/32 in |
0.5938 |
15.0813 |
|
39/64 in |
0.6094 |
15.4781 |
|
15.5 mm |
0.6102 |
15.5000 |
|
5/8 in |
0.6250 |
15.8750 |
|
16 mm |
0.6299 |
16.0000 |
|
41/64 in |
0.6406 |
16.2719 |
|
16.5 mm |
0.6496 |
16.5000 |
|
17 mm |
0.6693 |
17.0000 |
|
43/64 in |
0.6719 |
17.0656 |
|
11/16 in |
0.6875 |
17.4625 |
|
17.5 mm |
0.6890 |
17.5000 |
|
45/64 in |
0.7031 |
17.8594 |
|
18 mm |
0.7087 |
18.0000 |
|
23/32 in |
0.7188 |
18.2563 |
|
18.5 mm |
0.7284 |
18.5000 |
|
47/64 in |
0.7344 |
18.6531 |
|
19 mm |
0.7480 |
19.0000 |
|
3/4 in |
0.7500 |
19.0500 |
|
49/64 in |
0.7656 |
19.4469 |
|
19.5 mm |
0.7677 |
19.5000 |
|
25/32 in |
0.7813 |
19.8438 |
|
20 mm |
0.7874 |
20.0000 |
|
51/64 in |
0.7969 |
20.2406 |
|
20.5 mm |
0.8071 |
20.5000 |
|
13/16 in |
0.8125 |
20.6375 |
|
21 mm |
0.8268 |
21.0000 |
|
53/64 in |
0.8281 |
21.0344 |
|
27/32 in |
0.8438 |
21.4313 |
|
21.5 mm |
0.8465 |
21.5000 |
|
55/64 in |
0.8594 |
21.8281 |
|
22 mm |
0.8661 |
22.0000 |
|
7/8 in |
0.8750 |
22.2250 |
|
22.5 mm |
0.8858 |
22.5000 |
|
57/64 in |
0.8906 |
22.6219 |
|
23 mm |
0.9055 |
23.0000 |
|
29/32 in |
0.9063 |
23.0188 |
|
21/23 in |
0.9130 |
23.1913 |
|
59/64 in |
0.9219 |
23.4156 |
|
23.5 mm |
0.9252 |
23.5000 |
|
15/16 in |
0.9375 |
23.8125 |
|
24 mm |
0.9449 |
24.0000 |
|
61/64 in |
0.9531 |
24.2094 |
|
24.5 mm |
0.9646 |
24.5000 |
|
31/32 in |
0.9688 |
24.6063 |
|
25 mm |
0.9843 |
25.0000 |
|
63/64 in |
0.9844 |
25.0031 |
|
1 in |
1.0000 |
25.4000 |
|
25.5 mm |
1.0039 |
25.5000 |
|
1 1/64 in |
1.0156 |
25.7969 |
|
26 mm |
1.0236 |
26.0000 |
|
1 1/32 in |
1.0313 |
26.1938 |
|
26.5 mm |
1.0433 |
26.5000 |
|
1 3/64 in |
1.0469 |
26.5906 |
|
1 1/16 in |
1.0625 |
26.9875 |
|
27 mm |
1.0630 |
27.0000 |
|
1 5/64 in |
1.0781 |
27.3844 |
|
27.5 mm |
1.0827 |
27.5000 |
|
1 3/32 in |
1.0938 |
27.7813 |
|
28 mm |
1.1024 |
28.0000 |
|
1 7/64 in |
1.1094 |
28.1781 |
|
28.5 mm |
1.1221 |
28.5000 |
|
1 1/8 in |
1.1250 |
28.5750 |
|
1 9/64 in |
1.1406 |
28.9719 |
|
29 mm |
1.1417 |
29.0000 |
|
1 5/32 in |
1.1563 |
29.3688 |
|
29.5 mm |
1.1614 |
29.5000 |
|
1 11/64 in |
1.1719 |
29.7656 |
|
30 mm |
1.1811 |
30.0000 |
|
1 3/16 in |
1.1875 |
30.1625 |
|
30.5 mm |
1.2008 |
30.5000 |
|
1 13/64 in |
1.2031 |
30.5594 |
|
1 7/32 in |
1.2188 |
30.9563 |
|
31 mm |
1.2205 |
31.0000 |
|
1 15/64 in |
1.2344 |
31.3531 |
|
31.5 mm |
1.2402 |
31.5000 |
|
1 1/4 in |
1.2500 |
31.7500 |
|
32 mm |
1.2598 |
32.0000 |
|
1 17/64 in |
1.2656 |
32.1469 |
|
32.5 mm |
1.2795 |
32.5000 |
|
1 9/32 in |
1.2813 |
32.5438 |
|
1 19/64 in |
1.2969 |
32.9406 |
|
33 mm |
1.2992 |
33.0000 |
|
1 5/16 in |
1.3125 |
33.3375 |
|
33.5 mm |
1.3189 |
33.5000 |
|
1 21/64 in |
1.3281 |
33.7344 |
|
34 mm |
1.3386 |
34.0000 |
|
1 11/32 in |
1.3438 |
34.1313 |
|
34.5 mm |
1.3583 |
34.5000 |
|
1 23/64 in |
1.3594 |
34.5281 |
|
1 3/8 in |
1.3750 |
34.9250 |
|
35 mm |
1.3780 |
35.0000 |
|
1 25/64 in |
1.3906 |
35.3219 |
|
35.5 mm |
1.3976 |
35.5000 |
|
1 13/32 in |
1.4063 |
35.7188 |
|
36 mm |
1.4173 |
36.0000 |
|
1 27/64 in |
1.4219 |
36.1156 |
|
36.5 mm |
1.4370 |
36.5000 |
|
1 7/16 in |
1.4375 |
36.5125 |
|
1 29/64 in |
1.4531 |
36.9094 |
|
37 mm |
1.4567 |
37.0000 |
|
1 15/32 in |
1.4688 |
37.3063 |
|
37.5 mm |
1.4764 |
37.5000 |
|
1 31/64 in |
1.4844 |
37.7031 |
|
38 mm |
1.4961 |
38.0000 |
|
1 1/2 in |
1.5000 |
38.1000 |