Published: Jun 09, 2021
Modified: Jun 09, 2021
By Rob Siegwart
Thread tables for Unified coarse and fine threads along with tensile area and
equivalent tensile area diameter per equation A-3-7 from Ref . Tap drills
are for 75% thread engagement, per Tables 3 and 4 of Ref of section
"Threading".
UNC
Size, Number or Inches
Basic Major Diameter (in)
TPI
Tensile Area, in2
Tensile Area Diameter, in
Tap Drill No
Tap Drill Size, in
Clearance Drill (Close)
Clearance Size (Close), in
Clearance Drill (Free)
Clearance Size (Free), in
0
0.0600
52
0.0635
50
0.07
1
0.0730
64
0.0026
0.058
53
0.0595
48
0.076
46
0.081
2
0.0860
56
0.0037
0.069
50
0.07
43
0.089
41
0.096
3
0.0990
48
0.0049
0.079
47
0.0785
37
0.104
35
0.11
4
0.1120
40
0.0060
0.088
43
0.089
32
0.116
30
0.1285
5
0.1250
40
0.0080
0.101
38
0.1015
30
0.1285
29
0.136
6
0.1380
32
0.0091
0.108
36
0.1065
27
0.144
25
0.1495
8
0.1640
32
0.0140
0.134
29
0.136
18
0.1695
16
0.177
10
0.1900
24
0.0175
0.149
25
0.1495
9
0.196
7
0.201
12
0.2160
24
0.0242
0.175
16
0.177
2
0.221
1
0.228
1/4
0.25
20
0.0318
0.201
7
0.201
F
0.257
H
0.266
5/16
0.3125
18
0.0524
0.258
F
0.257
P
0.323
Q
0.332
3/8
0.375
16
0.0775
0.314
5/16
0.3125
W
0.386
X
0.397
7/16
0.4375
14
0.1063
0.368
U
0.368
29/64
0.4531
15/32
0.4687
1/2
0.5
13
0.1419
0.425
27/64
0.4219
33/64
0.5156
17/32
0.5312
9/16
0.5625
12
0.1819
0.481
31/64
0.4844
5/8
0.625
11
0.2260
0.536
17/32
0.5312
3/4
0.75
10
0.3345
0.653
21/32
0.6562
7/8
0.875
9
0.4617
0.767
49/64
0.7656
1
1
8
0.6057
0.878
7/8
0.875
1 1/8
1.125
7
0.7633
0.986
63/64
0.9844
1 1/4
1.25
7
0.9691
1.111
1 7/64
1.1094
1 5/16
1.3125
7
1.0812
1.173
1 3/8
1.375
6
1.1549
1.213
1 7/32
1.2187
1 1/2
1.5
6
1.4052
1.338
1 11/32
1.3437
1 5/8
1.625
6
1.6802
1.463
1 3/4
1.75
5
1.8995
1.555
1 9/16
1.5625
1 7/8
1.875
5
2.2171
1.680
1 11/16
1.6875
2
2
4.5
2.4982
1.783
1 25/32
1.7812
2 1/4
2.25
4.5
3.2477
2.033
2 1/32
2.0312
2 1/2
2.5
4
3.9988
2.256
2 1/4
2.25
2 3/4
2.75
4
4.9340
2.506
3
3
4
5.9674
2.756
3 1/4
3.25
4
7.0989
3.006
3 1/2
3.5
4
8.3286
3.256
3 3/4
3.75
4
9.6565
3.506
4
4
4
11.0825
3.756
UNF
Size, Number or Inches
Basic Major Diameter (in)
TPI
Tensile Area, in2
Tensile Area Diameter, in
Tap Drill No
Tap Drill Size, in
Clearance Drill (Close)
Clearance Size (Close), in
Clearance Drill (Free)
Clearance Size (Free), in
0
0.060
80
0.0018
0.048
3/64
0.0469
52
0.0635
50
0.07
1
0.073
72
0.0028
0.059
53
0.0595
48
0.076
46
0.081
2
0.086
64
0.0039
0.071
50
0.07
43
0.089
41
0.096
3
0.099
56
0.0052
0.082
45
0.082
37
0.104
35
0.11
4
0.112
48
0.0066
0.092
42
0.0935
32
0.116
30
0.1285
5
0.125
44
0.0083
0.103
37
0.104
30
0.1285
29
0.136
6
0.138
40
0.0101
0.114
33
0.113
27
0.144
25
0.1495
8
0.164
36
0.0147
0.137
29
0.136
18
0.1695
16
0.177
10
0.19
32
0.0200
0.160
21
0.159
9
0.196
7
0.201
12
0.216
28
0.0258
0.181
14
0.182
2
0.221
1
0.228
1/4
0.25
28
0.0364
0.215
3
0.213
F
0.257
H
0.266
5/16
0.3125
24
0.0581
0.272
I
0.272
P
0.323
Q
0.332
3/8
0.375
24
0.0878
0.334
Q
0.332
W
0.386
X
0.397
7/16
0.4375
20
0.1187
0.389
25/64
0.3906
29/64
0.4531
15/32
0.4687
1/2
0.5
20
0.1600
0.451
29/64
0.4531
33/64
0.5156
17/32
0.5312
9/16
0.5625
18
0.2030
0.508
33/64
0.5156
5/8
0.625
18
0.2560
0.571
37/64
0.5781
3/4
0.75
16
0.3730
0.689
11/16
0.6875
7/8
0.875
14
0.5095
0.805
13/16
0.8125
1
1
12
0.6630
0.919
59/64
0.9219
1 1/8
1.125
12
0.8557
1.044
1 3/64
1.0469
1 1/4
1.25
12
1.0729
1.169
1 11/64
1.1719
1 5/16
1.3125
12
1.1908
1.231
1 3/8
1.375
12
1.3147
1.294
1 19/64
1.2969
1 1/2
1.5
12
1.5810
1.419
1 27/64
1.4219
References