Decimal Equivalency Chart
Inch
Dec-imal
Wire
mm
TapSizes
.0059
97
.15
.0390
61
.1100
35
.0063
96
.16
.0394
1.
.1102
2.8
.0067
95
.17
.0400
60
.1110
34
.0071
94
.18
.0410
59
.1130
33
#6-40
.0075
93
.19
.0413
1.05
.1142
2.9
.0079
92
.20
.0420
58
.1160
32
.0083
91
.21
.0430
57
.1181
3.
.0087
90
.22
.0433
1.1
.1200
31
.0091
89
.23
.0453
1.15
.1220
3.1
.0094
.24
.0465
56
1/8
.1250
5/32-32NS
.0095
88
3/64
.0469
#0-80
.1260
3.2
.0098
.25
.0472
1.2
.1280
3.25
.0100
87
.0492
1.25
.1285
30
5/32-36NS
.0102
.26
.0512
1.3
.1299
3.3
.0105
86
.0520
55
.1339
3.4
.0106
.27
.0531
1.35
.1360
29
#8-32
.0110
85
.28
.0550
54
.1378
3.5
.0114
.29
.0551
1.4
.1405
28
.0015
84
.0571
1.45
9/64
.1406
.0118
.30
.0591
1.5
.1417
3.6
.0120
83
.0595
53
.1440
27
.0125
82
.0610
1.55
.1457
3.7
.0126
.32
1/16
.0625
#1-64
.1470
26
3/16-24NS
.0130
81
.0630
1.6
.1476
3.75
.0134
.34
.0635
52
#1-72
.1495
25
#10-24
.0135
80
.0650
1.65
.1496
3.8
.0138
.35
.0669
1.7
.1520
24
.0142
.36
.0670
51
#2-56
.1535
3.9
.0145
79
.0689
1.75
.1540
23
.0150
.38
.0700
50
#2-64
5/32
.1562
1/64
.0156
.0709
1.8
.1570
22
3/16-32NS
.0157
.4
.0728
1.85
.1575
4.
.0160
78
.0730
49
.1590
21
#10-32
.0165
.42
.0748
1.9
.1610
20
.0173
.44
.0760
48
.1614
4.1
.0177
.45
.0768
1.95
.1654
4.2
.0180
77
5/64
.0781
#3-48
.1660
19
.0181
.46
.0785
47
.1673
4.25
.0189
.48
.0787
2.
.1693
4.3
.0197
.5
.0807
2.05
.1695
18
.0200
76
.0810
46
#3-56
11/64
.1719
.0210
75
.0820
45
.1730
17
#12-24
.0217
.55
.0827
2.1
.1732
4.4
.0225
74
.0846
2.15
.1770
16
7/32-24NS
.0236
.6
.0860
44
.1772
4.5
.0240
73
.0866
2.2
.1800
15
#12-28
.0250
72
.0886
2.25
.1811
4.6
.0256
.65
.0890
43
#4-40
.1820
14
.0260
71
.0906
2.3
.1850
13
.0276
.7
.0925
2.35
4.7
.0280
70
.0935
42
#4-48
.1870
4.75
.0292
69
3/32
.0938
3/16
.1875
.0295
.75
.0945
2.4
.1890
4.8
.0310
68
.0960
41
12
7/32-32NS
1/32
.0312
.0965
2.45
.1910
11
.0315
.8
.0980
40
.1929
4.9
.0320
67
.0984
2.5
.1935
10
.0330
66
.0995
39
#5-40
.1960
9
.0335
.85
.1015
38
.1969
5.
.0350
65
.1024
2.6
.1990
8
1/4-20
.0354
.9
.1040
37
#5-44
.2008
5.1
.0360
64
.1063
2.7
.2010
7
.0370
63
.1065
36
#6-32
13/64
.2031
.0374
.95
.1083
2.75
.0380
62
7/64
.1094
Wire &Letter
Tap Sizes
.2040
6
21/64
.3281
11/16
.6875
3/4-16NF
.2047
5.2
.3307
8.4
.6890
17.5
.2055
5
.3320
Q
3/8-24NF
45/64
.7031
.2067
5.25
.3346
8.5
.7087
18.
.2087
5.3
.3386
8.6
23/32
.7188
1/2-14 Pipe
.2090
4
.3390
R
1/8-27 Pipe
.7283
18.5
.2126
5.4
.3425
8.7
47/64
.7344
.2130
3
1/4-28
11/32
.3438
.7480
19.
.2165
5.5
.3445
8.75
3/4
.7500
7/32
.2188
.3465
8.8
49/64
.7656
7/8-9NC
.2205
5.6
.3480
S
.7677
19.5
.2210
2
.3504
8.9
25/32
.7812
.2244
5.7
.3543
9.
.7874
20.
.2264
5.75
.3580
T
51/64
.7969
.2280
1
.3583
9.1
.8071
20.5
.2283
5.8
23/64
.3594
13/16
.8125
7/8-14NF
.2323
5.9
.3622
9.2
.8268
21.
.2340
A
.3642
9.25
53/64
.8281
15/64
.2344
.3661
9.3
27/32
.8438
.2362
6.
.3680
U
7/16-14NC
.8465
21.5
.2380
B
.3701
9.4
55/64
.8594
.2402
6.1
.3740
9.5
.8661
22.
.2420
C
3/8
.3750
7/8
.8750
1-8NC
.2441
6.2
.3770
V
.8858
22.5
.2460
D
.3780
9.6
57/64
.8906
.2461
6.25
.3819
9.7
.9055
23.
.2480
6.3
.3839
9.75
29/32
.9062
1-12NF
1/4
.2500
E
.3858
9.8
59/64
.9219
3/4-14 Pipe
.2520
6.4
.3860
W
7/16-20
.9252
23.5
.2559
6.5
.3898
9.9
15/16
.9375
1-14NS
.2570
F
5/16-18NC
25/64
.3906
.9449
24.
.2598
6.6
.3937
10.
61/64
.9531
.2610
G
.3970
X
.9646
24.5
.2638
6.7
.4040
Y
31/32
.9688
17/64
.2656
13/32
.4062
.9843
25.
.2657
6.75
.4130
Z
63/64
.9844
1-1/8-7NC
.2660
H
.4134
10.5
1.0000
.2677
6.8
27/64
.4219
1/2-13
1.0093
25.5
.2717
6.9
.4331
11.
1-1/64
1.0156
.2720
I
5/16-24NF
7/16
.4375
1/4-18 Pipe
1.0236
26.
.2756
7.
.4528
11.5
1-1/32
1.0312
.2770
J
29/64
.4531
1/2-20
1.0433
26.5
.2795
7.1
15/32
.4688
1-3/64
1.0469
1-1/8-12NF
.2810
K
.4724
12.
1-1/16
1.0625
9/32
.2812
5/16-32NS
31/64
.4844
9/16-12
1.0630
27.
.2835
7.2
.4921
12.5
1-5/64
1.0781
.2854
7.25
1/2
.5000
1.0827
27.5
.2874
7.3
.5118
13.
1-3/32
1.0938
.2900
L
33/64
.5156
9/16-18
1.1024
28.
.2913
7.4
17/32
.5312
1-7/64
1.1094
1-1/4-7NC
.2950
M
.5315
13.5
1.1220
28.5
.2953
7.5
35/64
.5469
1-1/8
1.1250
19/64
.2969
.5512
14.
5/8-11
1-9/64
1.1406
.2992
7.6
9/16
.5625
1.1417
29.
.3020
N
.5709
14.5
1-5/32
1.1562
1-11-1/2 Pipe
.3031
7.7
37/64
.5781
5/8-18NF
1.1614
29.5
.3051
7.75
.5906
15.
3/8-18 Pipe
1-11/64
1.1719
1-1/4-12NF
.3071
7.8
19/32
.5938
1.1811
30.0
.3110
7.9
39/64
.6094
1-3/16
1.1875
1-3/8 x 6
5/16
.3125
3/8-16NC
.6102
15.5
1.2008
30.5
.3150
8.
5/8
.6250
11/16-16NS
1-13/64
1.2031
.3160
O
.6299
16.
1-7/32
1.2188
.3189
8.1
41/64
.6406
1.2205
31.0
.3228
8.2
.6496
16.5
1-15/64
1.2344
.3230
P
21/32
.6562
3/4-10NC
1.2402
31.5
.3248
8.25
.6693
17.
1-1/4
1.2500
.3268
8.3
43/64
.6719
