|
Size(mm) |
Size(in) |
Fraction(inch) |
Letter or Number |
Description |
|
0.2 |
0.0079 |
|
|
|
|
0.22 |
0.0087 |
|
|
|
|
0.25 |
0.0098 |
|
|
|
|
0.28 |
0.0110 |
|
|
|
|
0.3 |
0.0118 |
|
|
|
|
0.32 |
0.0126 |
|
|
|
|
0.35 |
0.0138 |
|
80 |
|
|
0.38 |
0.0150 |
|
79 |
|
|
0.39 |
0.0156 |
1/64 |
|
|
|
0.4 |
0.0157 |
|
78 |
|
|
0.42 |
0.0165 |
|
|
|
|
0.45 |
0.0177 |
|
77 |
|
|
0.48 |
0.0189 |
|
|
|
|
0.5 |
0.0197 |
|
76 |
|
|
0.52 |
0.0205 |
|
75 |
|
|
0.55 |
0.0217 |
|
|
|
|
0.58 |
0.0228 |
|
74 |
|
|
0.6 |
0.0236 |
|
73 |
Tapping Drill 16 BA |
|
0.62 |
0.0244 |
|
72 |
|
|
0.65 |
0.0256 |
|
71 |
|
|
0.68 |
0.0268 |
|
|
|
|
0.7 |
0.0276 |
|
70 |
Tapping Drill 15 BA |
|
0.72 |
0.0283 |
|
|
|
|
0.75 |
0.0295 |
|
69 |
Tapping Drill ISO metric coarse
1 mm |
|
0.78 |
0.0307 |
|
|
|
|
0.79 |
0.0312 |
1/32 |
68 |
|
|
0.8 |
0.0315 |
|
|
Tapping Drill 14 BA |
|
0.82 |
0.0323 |
|
67 |
|
|
0.85 |
0.0335 |
|
66 |
Tapping Drill ISO Metric Coarse
1.1 mm |
|
0.88 |
0.0346 |
|
|
|
|
0.9 |
0.0354 |
|
65 |
|
|
0.92 |
0.0362 |
|
64 |
|
|
0.95 |
0.0374 |
|
63 |
Tapping Drill ISO Metric Coarse
1.2 mm |
|
0.98 |
0.0386 |
|
62 |
Tapping Drill 13 BA |
|
1 |
0.0394 |
|
61 |
Tapping Drill 12 BA and 17swg
CEI |
|
1.05 |
0.0413 |
|
60 |
Tapping Drill 12 BA |
|
1.1 |
0.0433 |
|
59 |
Tapping Dnll ISO Metric Coarse
1.4 mm |
|
1.15 |
0.0453 |
|
58 |
|
|
1.19 |
0.0469 |
3/64 |
57 |
Tapping Drill 16swg CEI |
|
1.2 |
0.0472 |
|
56 |
Tapping Drill 11 BA and 1/16
Whitworth |
|
1.25 |
0.0492 |
|
|
Tapping Dnll ISO Metric Coarse
1.6 mm and No 0 UNF |
|
1.3 |
0.0512 |
|
55 |
|
|
1.35 |
0.0531 |
|
|
Tapping Drill ISO Metric Special
Pitches 1.7 mm |
|
1.4 |
0.0551 |
|
54 |
Tapping Drill 15swg CEI and
10BA |
|
1.45 |
0.0571 |
|
|
Tapping Drill ISO Metric Coarse
1.8 mm |
|
1.5 |
0.0591 |
|
53 |
Tapping Drill 9 BA |
|
1.55 |
0.0610 |
|
|
Tapping Drill ISO Metric Special
Pitches 2 mm and No1 UNC |
|
1.58 |
0.0625 |
1/16 |
|
|
|
1.6 |
0.0630 |
|
52 |
Tapping Drill ISO Metric Coarse
2 mm, No1 UNF and 14swg CEI |
|
1.65 |
0.0650 |
|
|
|
|
1.7 |
0.0669 |
|
51 |
|
|
1.75 |
0.0689 |
|
|
Tapping Drill ISO Metric Coarse
2.2 mm |
|
1.8 |
0.0709 |
|
50 |
Tapping Drill 8 BA |
|
1.85 |
0.0728 |
|
49 |
Tapping Drill 3/32 Whitworth,
No2 UNC and 13swg CEI |
|
1.9 |
0.0748 |
|
48 |
Tapping Drill ISO Metric
Special Pitches 2.3 mm and No2 UNF |
|
1.95 |
0.0768 |
|
|
|
|
1.98 |
0.0781 |
5/64 |
|
|
|
2 |
0.0787 |
|
47 |
Tapping Drill 7 BA |
|
2.05 |
0.0807 |
|
46 |
Tapping Drill ISO Metric Coarse
2.5 mm and 12swg CEI |
|
2.1 |
0.0827 |
|
45 |
Tapping Drill No3 UNC |
|
2.15 |
0.0846 |
|
|
Tapping Drill ISO Metric
Special Pitches 2.6 mm and No3 UNF |
|
2.2 |
0.0866 |
|
44 |
|
|
2.25 |
0.0886 |
|
43 |
|
|
2.3 |
0.0906 |
|
|
Tapping Drill 6 BA |
|
2.35 |
0.0925 |
|
|
Tapping Drill No4 UNC |
|
2.38 |
0.0938 |
3/32 |
42 |
|
|
2.4 |
0.0945 |
|
|
Tapping Drill ISO Metric
Special Pitches 3 mm and No4 UNF |
|
2.45 |
0.0965 |
|
41 |
|
|
2.5 |
0.0984 |
|
40 |
Tapping Drill ISO Metric Coarse
3 mm |
|
2.55 |
0.1004 |
|
39 |
Tapping Drill 1/8 Whitworth 1/8
BSC and 1/8 CEI |
|
2.6 |
0.1024 |
|
38 |
Tapping Drill 5 BA |
|
2.65 |
0.1043 |
|
37 |
Tapping Drill ISO Metric Fine 3
mm and No5 UNC |
|
2.7 |
0.1063 |
|
36 |
Tapping Drill No5 UNF |
|
2.75 |
0.1083 |
|
|
|
|
2.78 |
0.1094 |
7/64 |
|
|
|
2.8 |
0.1102 |
|
35 |
|
|
2.85 |
0.1122 |
|
34 |
Tapping Drill No6 UNC |
|
2.9 |
0.1142 |
|
33 |
Tapping Drill ISO Metric Coarse
3.5 mm |
|
2.95 |
0.1161 |
|
32 |
Tapping Drill 4 BA and No6 UNF |
|
3 |
0.1181 |
|
31 |
|
|
3.1 |
0.1220 |
|
|
|
|
3.18 |
0.1250 |
1/8 |
|
|
|
3.2 |
0.1260 |
|
30 |
Tapping Drill 5/32 BSC, 5/32
WW, ISO Metric Special Pitches 2.3mm & 0.154 CEI |
|
3.3 |
0.1299 |
|
|
Tapping Drill ISO Metric Coarse
4 mm |
|
3.4 |
0.1339 |
|
29 |
Tapping Drill 3 BA |
|
3.5 |
0.1378 |
|
|
Tapping Drill ISO Metric Fine 4
mm and No8 UNC |
|
3.55 |
0.1398 |
|
|
Tapping Drill No8 UNF |
|
3.57 |
0.1406 |
9/64 |
28 |
|
|
3.6 |
0.1417 |
|
27 |
Tapping Drill 0.175 CEI |
|
3.7 |
0.1457 |
|
26 |
Tapping Drill 3/16 Whitworth |
|
3.8 |
0.1496 |
|
25 |
Tapping Drill ISO Metric Coarse
4.5 mm |
|
3.9 |
0.1535 |
|
24 |
Tapping Drill No10 UNC |
|
3.97 |
0.1562 |
5/32 |
23 |
Tapping Drill 3/16 BSF 3/16 CEI
and 3/16 BSC |
|
4 |
0.1575 |
|
22 |
Tapping Drill 2 BA |
|
4.1 |
0.1614 |
|
21 |
Tapping Drill ISO Metric
Special Pitches 5 mm and No 10 UNF |
|
4.2 |
0.1654 |
|
20 |
Tapping Drill ISO Metric Coarse
5 mm |
|
4.3 |
0.1693 |
|
19 |
|
|
4.37 |
0.1719 |
11/64 |
18 |
|
|
4.4 |
0.1732 |
|
17 |
|
|
4.5 |
0.1772 |
|
16 |
Tapping Drill 1 BA, 7/32
Whitworth, and ISO Metric Fine 5 mm |
|
4.55 |
0.1791 |
|
|
Tapping Drill No12 UNC |
|
4.6 |
0.1811 |
|
15 |
Tapping Drill 7/32 BSF and ISO
Metric Special Pitches 5.5 mm |
|
4.65 |
0.1831 |
|
|
Tapping Drill No 12 UNF |
|
4.7 |
0.1850 |
|
14 |
|
|
4.76 |
0.1875 |
3/16 |
13 |
|
|
4.8 |
0.1890 |
|
12 |
|
|
4.9 |
0.1929 |
|
11 |
|
|
5 |
0.1969 |
|
10 |
Tapping Drill ISO Metric Coarse
6 mm |
|
5.1 |
0.2008 |
|
9 |
Tapping Drill 0 BA and 1/4
Whitworth |
|
5.16 |
0.2031 |
13/64 |
8 |
|
|
5.2 |
0.2047 |
|
7 |
Tapping Drill 1/4 UNC and ISO
Metric Fine 6 mm |
|
5.3 |
0.2087 |
|
6 |
Tapping Drill 1/4 BSF |
|
5.4 |
0.2126 |
|
5 |
|
|
5.5 |
0.2165 |
|
4 |
Tapping Drill 1/4 UNF |
|
5.56 |
0.2188 |
7/32 |
3 |
Tapping Drill 1/4 BSC and 1/4
CEI |
|
5.6 |
0.2205 |
|
2 |
|
|
5.7 |
0.2244 |
|
|
|
|
5.8 |
0.2283 |
|
1 |
Tapping Drill 0.266 CEI |
|
5.9 |
0.2323 |
|
A |
|
|
5.95 |
0.2344 |
15/64 |
|
|
|
6 |
0.2362 |
|
B |
Tapping Drill ISO Metric Coarse
7 mm and 9/32 BSF |
|
6.1 |
0.2402 |
|
C |
|
|
6.2 |
0.2441 |
|
D |
Tapping Drill 9/32 BSC, 0.281
CEI and ISO Metric Fine 7 mm |
|
6.3 |
0.2480 |
|
E |
|
|
6.35 |
0.2500 |
1/4 |
|
|
|
6.4 |
0.2520 |
|
|
Tapping Drill 1/16 BSTP |
|
6.5 |
0.2559 |
|
F |
Tapping Drill 5/16 Whitworth |
|
6.6 |
0.2598 |
|
G |
Tapping Drill 5/16 UNC and 1/16
BSP |
|
6.7 |
0.2638 |
|
H |
|
|
6.75 |
0.2655 |
17/64 |
|
Tapping Drill 5/16 BSF |
|
6.8 |
0.2677 |
|
|
Tapping Drill ISO Metric Coarse
8 mm |
|
6.9 |
0.2717 |
|
I |
Tapping Drill 5/16 UNF |
|
7 |
0.2756 |
|
J |
Tapping Drill 5/16 BSC, ISO
Metric Fine 8 mm and 5/16 CEI |
|
7.1 |
0.2795 |
|
K |
|
|
7.14 |
0.2812 |
9/32 |
|
|
|
7.2 |
0.2835 |
|
|
Tapping Drill ISO Metric Special
Pitches 8 mm |
|
7.3 |
0.2874 |
|
L |
|
|
7.4 |
0.2913 |
|
M |
|
|
7.5 |
0.2953 |
|
|
|
|
7.54 |
0.2969 |
19/64 |
|
|
|
7.6 |
0.2992 |
|
N |
|
|
7.7 |
0.3031 |
|
|
|
|
7.8 |
0.3071 |
|
|
Tapping Dnll ISO Metric Coarse 9
mm |
|
7.9 |
0.3110 |
|
|
|
|
7.94 |
0.3125 |
5/16 |
|
Tapping Drill 3/8 Whitworth |
|
8 |
0.3150 |
|
0 |
Tapping Drill 3/8 UNC and ISO
Metric Special Pitches 9 mm |
|
8.1 |
0.3189 |
|
|
|
|
8.2 |
0.3228 |
|
P |
Tapping Drill 3/8 BSF |
|
8.3 |
0.3268 |
|
|
|
|
8.33 |
0.3281 |
21/64 |
|
|
|
8.4 |
0.3307 |
|
Q |
Tapping Drill 1/8 BSTP |
|
8.5 |
0.3346 |
|
|
Tapping Drill ISO Metric Coarse
10 mm and 3/8 UNF |
|
8.6 |
0.3386 |
|
R |
Tapping Drill 3/8 BSC and 3/8
CEI |
|
8.7 |
0.3425 |
|
|
|
|
8.73 |
0.3438 |
11/32 |
|
Tapping Drill 1/8 BSP |
|
8.8 |
0.3465 |
|
5 |
Tapping Drill ISO Metric Fine 10
mm |
|
8.9 |
0.3504 |
|
|
|
|
9 |
0.3543 |
|
|
Tapping Drill ISO Metric Special
Pitches 10 mm |
|
9.1 |
0.3583 |
|
T |
|
|
9.13 |
0.3594 |
23/64 |
|
|
|
9.2 |
0.3622 |
|
|
Tapping Drill ISO Metric Special
Pitches 10 mm |
|
9.3 |
0.3661 |
|
U |
Tapping Drill 7/16 Whitworth |
|
9.4 |
0.3701 |
|
|
Tapping Drill 7/16 UNC |
|
9.5 |
0.3740 |
|
V |
Tapping Dnll ISO Metric Coarse
11 mm |
|
9.53 |
0.3750 |
3/8 |
|
|
|
9.6 |
0.3780 |
|
|
|
|
9.7 |
0.3819 |
|
|
Tapping Drill 7/16 BSF |
|
9.8 |
0.3858 |
|
W |
|
|
9.9 |
0.3898 |
|
|
Tapping Drill 7/16 UNF |
|
9.92 |
0.3906 |
25/64 |
|
|
|
10 |
0.3937 |
|
|
|
|
10.1 |
0.3976 |
|
X |
Tapping Drill 7/16 BSC |
|
10.2 |
0.4016 |
|
|
Tapping Drill ISO Metric Coarse
12 mm |
|
10.3 |
0.4055 |
|
Y |
|
|
10.32 |
0.4062 |
13/32 |
|
|
|
10.4 |
0.4094 |
|
|
|
|
10.5 |
0.4134 |
|
Z |
Tapping Drill 1/2 Whitworth and
ISO Metric Special Pitches 12 mm (1.5 mm pitch) |
|
10.6 |
0.4173 |
|
|
|
|
10.7 |
0.4213 |
|
|
|
|
10.72 |
0.4219 |
27/64 |
|
|
|
10.8 |
0.4252 |
|
|
Tapping Drill 1/2 UNC and ISO
Metric Fine 12 mm |
|
10.9 |
0.4291 |
|
|
|
|
11 |
0.4331 |
|
|
Tapping Drill ISO Metric Special
Pitches 12 mm (1mm pitch) |
|
11.1 |
0.4370 |
|
|
|
|
11.11 |
0.4375 |
7/16 |
|
Tapping Drill 1/2 BSF |
|
11.2 |
0.4409 |
|
|
Tapping Drill 1/4 BSTP |
|
11.3 |
0.4449 |
|
|
|
|
11.4 |
0.4488 |
|
|
Tapping Drill 1/2 UNF |
|
11.5 |
0.4528 |
|
|
|
|
11.51 |
0.4531 |
29/64 |
|
|
|
11.6 |
0.4567 |
|
|
|
|
11.7 |
0.4606 |
|
|
|
|
11.8 |
0.4646 |
|
|
Tapping Drill 1/4 BSP |
|
11.9 |
0.4685 |
|
|
|
|
11.91 |
0.4688 |
15/32 |
|
|
|
12 |
0.4724 |
|
|
Tapping Drill ISO Metric Coarse
14 mm |
|
12.1 |
0.4764 |
|
|
Tapping Drill 9/16 Whitworth |
|
12.2 |
0.4803 |
|
|
Tapping Drill 9/16 UNC |
|
12.3 |
0.4843 |
|
|
|
|
12.3 |
0.4844 |
31/64 |
|
|
|
12.4 |
0.4882 |
|
|
|
|
12.5 |
0.4921 |
|
|
Tapping Drill ISO Metric Special
Pitches 14 mm |
|
12.6 |
0.4961 |
|
|
|
|
12.7 |
0.5000 |
1/2 |
|
Tapping Drill 9/16 BSF |
|
12.8 |
0.5039 |
|
|
Tapping Drill ISO Metric Fine 14
mm |
|
12.9 |
0.5079 |
|
|
Tapping Drill 9/I 6 UNF |
|
13 |
0.5118 |
|
|
|
|
13.1 |
0.5156 |
33/64 |
|
Tapping Drill 9/16 BSC and 9/16
CEI |
|
13.1 |
0.5157 |
|
|
|
|
13.2 |
0.5197 |
|
|
|
|
13.3 |
0.5236 |
|
|
|
|
13.4 |
0.5276 |
|
|
|
|
13.49 |
0.5313 |
17/32 |
|
Tapping Drill 5/8 UNC |
|
13.5 |
0.5315 |
|
|
Tapping Drill 5/8 Whitworth |
|
13.6 |
0.5354 |
|
|
|
|
13.7 |
0.5394 |
|
|
|
|
13.8 |
0.5433 |
|
|
|
|
13.89 |
0.5469 |
35/64 |
|
|
|
13.9 |
0.5472 |
|
|
|
|
14 |
0.5512 |
|
|
Tapping Drill ISO Metric Coarse
16 mm and 5/8 BSF |
|
14.25 |
0.5610 |
|
|
|
|
14.3 |
0.5625 |
9/16 |
|
|
|
14.5 |
0.5709 |
|
|
Tapping Drill 5/8 UNF and ISO
Metric Fine 16 mm |
|
14.68 |
0.5780 |
37/64 |
|
|
|
14.75 |
0.5807 |
|
|
Tapping Drill 3/8 BSTP |
|
15 |
0.5906 |
|
|
Tapping Drill 11/16 Whitworth,
ISO Metric Special Pitches 16 mm and 5/8 BSC |
|
15.08 |
0.5937 |
19/32 |
|
|
|
15.25 |
0.6004 |
|
|
Tapping Drill 3/8 BSP |
|
15.48 |
0.6094 |
39/64 |
|
|
|
15.5 |
0.6102 |
|
|
Tapping Drill ISO Metric Coarse
18 mm and 11/16 BSF |
|
15.75 |
0.6201 |
|
|
|
|
15.88 |
0.6252 |
5/8 |
|
|
|
16 |
0.6299 |
|
|
|
|
16.25 |
0.6398 |
|
|
|
|
16.27 |
0.6406 |
41/64 |
|
Tapping Drill 3/4 Whitworth |
|
16.5 |
0.6496 |
|
|
Tapping Drill 3/4 UNC and ISO
Metric Fine 18 mm |
|
16.67 |
0.6563 |
21/32 |
|
|
|
16.75 |
0.6594 |
|
|
Tapping Drill 3/4 BSF |
|
17 |
0.6693 |
|
|
|
|
17.07 |
0.6720 |
43/64 |
|
|
|
17.25 |
0.6791 |
|
|
|
|
17.46 |
0.6874 |
11/16 |
|
Tapping Drill 3/4 UNF |
|
17.5 |
0.6890 |
|
|
Tapping Drill ISO Metric Coarse
20 mm |
|
17.75 |
0.6988 |
|
|
|
|
17.86 |
0.7031 |
45/64 |
|
|
|
18 |
0.7087 |
|
|
Tapping Drill 13/16 Whitworth
and ISO Metric Special Pitches 20 mm (2 mm pitch) |
|
18.25 |
0.7185 |
|
|
Tapping Drill 1/2 BSTP |
|
18.26 |
0.7189 |
23/32 |
|
|
|
18.5 |
0.7283 |
|
|
Tapping Drill ISO Metric Fine 20
mm |
|
18.65 |
0.7343 |
47/64 |
|
|
|
18.75 |
0.7382 |
|
|
|
|
19 |
0.7480 |
|
|
Tapping Drill ISO Metric Special
Pitches 20 mm (1 mm pitch) |
|
19.05 |
0.7500 |
3/4 |
|
Tapping Drill 1/2 BSP |
|
19.25 |
0.7579 |
|
|
Tapping Drill 7/8 Whitworth |
|
19.45 |
0.7656 |
49/64 |
|
Tapping Drill 7/8 UNC |
|
19.5 |
0.7677 |
|
|
Tapping Drill ISO Metric Coarse
22 mm |
|
19.75 |
0.7776 |
|
|
|
|
19.84 |
0.7812 |
25/32 |
|
Tapping Drill 7/8 BSF |
|
20 |
0.7874 |
|
|
|
|
20.24 |
0.7969 |
51/64 |
|
|
|
20.25 |
0.7972 |
|
|
|
|
20.5 |
0.8071 |
|
|
Tapping Drill ISO Metric Fine 22
mm |
|
20.64 |
0.8125 |
13/16 |
|
Tapping Drill 7/8 UNF |
|
20.75 |
0.8169 |
|
|
Tapping Drill 15/16 Whitworth |
|
21 |
0.8268 |
|
|
Tapping Drill ISO Metric Coarse
24 mm |
|
21.03 |
0.8281 |
53/64 |
|
Tapping Drill 5/8 BSP |
|
21.25 |
0.8366 |
|
|
|
|
21.43 |
0.8438 |
27/32 |
|
|
|
21.5 |
0.8465 |
|
|
|
|
21.75 |
0.8563 |
|
|
|
|
21.83 |
0.8594 |
55/64 |
|
|
|
22 |
0.8661 |
|
|
Tapping Drill 1 inch Whitworth
and ISO Metric Fine 24 mm |
|
22.23 |
0.8750 |
7/8 |
|
|
|
22.25 |
0.8760 |
|
|
Tapping Drill I UNC |
|
22.5 |
0.8858 |
|
|
Tapping Drill ISO Metric Special
Pitches 24 mm (1.5 mm pitch) |
|
22.62 |
0.8906 |
57/64 |
|
|
|
22.75 |
0.8957 |
|
|
Tapping Drill 1 inch BSF |
|
23 |
0.9055 |
|
|
Tapping Drill ISO Metric Special
Pitches 24 mm (1 mm pitch) |
|
23.02 |
0.9062 |
29/32 |
|
|
|
23.25 |
0.9154 |
|
|
Tapping Drill I inch UNF |
|
23.42 |
0.9219 |
59/64 |
|
|
|
23.5 |
0.9252 |
|
|
Tapping Drill ISO Metric Special
Pitches 25 mm (1.5 mm pitch) |
|
23.75 |
0.9350 |
|
|
Tapping Drill 3/4 BSTP |
|
23.81 |
0.9375 |
15/16 |
|
|
|
24 |
0.9449 |
|
|
Tapping Drill ISO Metric Coarse
27 mm |
|
24.21 |
0.9531 |
61/64 |
|
|
|
24.25 |
0.9547 |
|
|
|
|
24.5 |
0.9646 |
|
|
Tapping Drill 3/4 BSP |
|
24.61 |
0.9688 |
31/32 |
|
Tapping Drill 1inch BSC and 1
inch CEI |
|
24.75 |
0.9744 |
|
|
|
|
25 |
0.9843 |
|
|
Tapping Drill ISO Metric Fine 27
mm |
|
25 |
0.9844 |
63/64 |
|
|
|
25.4 |
1.0000 |
1 |
|
|
|
|
|
|
|
Standards rise in Increments
of 1/64in and 0.50 mm. |
