DECIMAL EQUIVALENTS
Size
0.25
0.30
#80
0.35
#79
Decimal
Inches
.0098
.0118
.0135
.0138
.0145
Size
2.05
#46
#45
2.10
2.15
Decimal
Inches
.0807
.0810
.0820
.0827
.0846
Size
4.70
#13
3/16
4.80
#12
Decimal
Inches
.1850
.1850
.1875
.1890
.1890
1/64
0.40
#78
0.45
#77
.0156
.0157
.0160
.0177
.0180
#44
2.20
2.25
#43
2.30
.0860
.0866
.0886
.0890
.0905
#11
4.90
#10
#9
5.00
.1910
.1929
.1935
.1960
.1968
0.50
#76
#75
0.55
#74
.0197
.0200
.0210
.0217
.0225
2.35
#42
3/32
2.40
#41
.0925
.0935
.0937
.0945
.0960
#8
5.10
#7
13/64
#6
0.60
#73
#72
0.65
#71
.0236
.0240
.0250
.0256
.0260
2.45
#40
2.50
#39
2.55
.0965
.0980
.0984
.0995
.1004
0.70
#70
#69
0.75
#68
.0276
.0280
.0292
.0295
.0310
#38
2.60
#37
2.65
2.70
1/32
0.80
#67
#66
0.85
.0313
.0315
.0320
.0330
.0335
#65
0.90
#64
#63
0.95
Decimal
Inches
.3307
.3320
.3346
.3386
.3390
Size
14.25
9/16
14.50
37/64
14.75
Decimal
Inches
.5610
.5625
.5709
.5781
.5807
8.70
11/32
8.80
S
8.90
.3425
.3437
.3465
.3480
.3504
15.00
19/32
15.25
39/64
15.50
.5906
.5937
.6004
.6094
.6102
.1990
.2008
.2010
.2031
.2040
9.00
T
9.10
23/64
9.20
.3543
.3580
.3583
.3594
.3622
15.75
5/8
16.00
16.25
41/64
.6201
.6250
.6299
.6398
.6406
5.20
#5
5.30
#4
5.40
.2047
.2055
.2087
.2090
.2126
9.30
U
9.40
9.50
3/8
.3661
.3680
.3701
.3740
.3750
16.50
21/32
16.75
17.00
43/64
.6496
.6562
.6594
.6693
.6719
.1015
.1024
.1040
.1043
.1063
#3
5.50
7/32
5.60
#2
.2130
.2165
.2187
.2205
.2210
V
9.60
9.70
9.80
W
.3770
.3780
.3819
.3858
.3860
17.25
11/16
17.50
17.75
45/64
.6791
.6875
.6890
.6988
.7031
#36
2.75
7/64
#35
2.80
.1065
.1083
.1093
.1100
.1102
5.70
#1
5.80
5.90
A
.2244
.2280
.2283
.2323
.2340
9.90
25/64
10.00
X
10.10
.3898
.3906
.3937
.3970
.3976
18.00
18.25
23/32
18.50
47/64
.7087
.7185
.7187
.7283
.7344
.0350
.0354
.0360
.0370
.0374
#34
2.85
#33
2.90
#32
.1110
.1122
.1130
.1142
.1160
15/64
6.00
B
6.10
C
.2344
.2362
.2380
.2401
.2420
10.20
Y
10.30
13/32
10.40
.4016
.4040
.4055
.4062
.4094
18.75
19.00
3/4
19.25
49/64
.7382
.7480
.7500
.7579
.7656
#62
#61
1.00
#60
#59
.0380
.0390
.0394
.0400
.0410
2.95
3.00
#31
3.10
1/8
.1161
.1181
.1200
.1220
.1250
6.20
D
6.30
E-1/4
6.40
.2441
.2460
.2480
.2500
.2520
Z
10.50
10.60
10.70
27/64
.4130
.4134
.4173
.4213
.4219
19.50
19.75
25/32
20.00
51/64
.7677
.7776
.7812
.7874
.7969
1.05
#58
#57
1.10
1.15
.0413
.0420
.0430
.0433
.0453
3.20
#30
3.30
3.40
#29
.1260
.1285
.1299
.1339
.1360
6.50
F
6.60
G
6.70
.2559
.2570
.2598
.2610
.2638
10.80
10.90
11.00
11.10
7/16
.4252
.4291
.4330
.4370
.4375
20.25
20.50
13/16
.7972
.8071
.8125
#56
3/64
1.20
1.25
1.30
.0465
.0469
.0472
.0492
.0512
3.50
#28
9/64
3.60
#27
.1378
.1405
.1406
.1417
.1440
17/64
H
6.80
6.90
I
.2656
.2660
.2677
.2716
.2720
11.20
11.30
11.40
11.50
29/64
.4409
.4449
.4488
.4528
.4531
20.75
21.00
53/64
21.25
27/32
.8169
.8268
.8281
.8366
.8437
#55
1.35
1.40
#54
1.45
.0520
.0531
.0550
.0550
.0571
3.70
#26
#25
3.80
#24
.1457
.1470
.1495
.1496
.1520
7.00
J
7.10
K
9/32
.2756
.2770
.2795
.2810
.2812
11.60
11.70
11.80
11.90
15/32
.4567
.4606
.4646
.4685
.4687
21.50
21.75
55/64
22.00
7/8
.8465
.8563
.8594
.8661
.8750
1.50
#53
1.55
1/16
1.60
.0591
.0595
.0610
.0625
.0629
3.90
#23
5/32
#22
4.00
.1535
.1540
.1562
.1570
.1575
7.20
7.30
L
7.40
M
.2835
.2874
.2900
.2913
.2950
12.00
12.10
12.20
12.30
31/64
.4724
.4764
.4803
.4843
.4843
22.25
22.50
57/64
22.75
23.00
.8760
.8858
.8906
.8957
.9055
#52
1.65
1.70
#51
1.75
.0635
.0650
.0669
.0670
.0689
#21
#20
4.10
4.20
#19
.1590
.1610
.1614
.1654
.1660
7.50
19/64
7.60
N
7.70
.2953
.2968
.2992
.3020
.3031
12.40
12.50
12.60
12.70
1/2
.4882
.4921
.4961
.5000
.5000
29/32
23.25
59/64
23.50
23.75
.9062
.9154
.9219
.9252
.9350
#50
1.80
1.85
#49
1.90
.0700
.0709
.0730
.0730
.0748
4.30
#18
11/64
#17
4.40
.1693
.1695
.1719
.1730
.1732
7.80
7.90
5/16
8.00
O
.3071
.3110
.3125
.3150
.3160
12.80
12.90
13.00
33/64
13.20
.5039
.5079
.5118
.5156
.5197
15/16
24.00
61/64
24.25
24.50
.9375
.9449
.9531
.9547
.9646
#48
1.95
5/64
#47
2.00
.0760
.0768
.0781
.0785
.0787
#16
4.50
#15
4.60
#14
.1770
.1771
.1800
.1811
.1820
8.10
8.20
P
8.30
21/64
.3189
.3228
.3230
.3268
.3281
17/32
13.50
13.80
35/64
14.00
.5313
.5315
.5433
.5469
.5512
31/32
24.75
25.00
63/64
1”
.9688
.9744
.9843
.9844
1.0000
Size
8.40
Q
8.50
8.60
R
Tap Drill Sizes
(Drill sizes based on approximate 72-77% full thread)
Tap Size/
Pitch Form
Tap
Drill
Size
Alt.
Tap
Drill
3/64
53
53
51
50
47
46
43
42
39
37
36
33
29
29
25
21
17
15
7
3
F
I
5/16
Q
U
W
27/64
29/64
31/64
33/64
17/32
37/64
21/32
11/16
49/64
13/16
7/8
59/64
15/16
63/64
1.3/64
1.7/64
1.11/64
1.7/32
1.19/64
1.11/32
1.27/64
1.9/16
1.25/32
1.25
1.55
1.55
1.85
1.90
2.10
2.15
2.35
2.40
2.65
2.70
2.85
2.95
3.50
3.50
3.90
4.10
4.50
4.70
5.10
5.50
6.60
6.90
8.00
8.50
9.40
9.90
10.80
11.50
12.20
12.90
13.50
14.50
16.50
17.50
19.50
20.40
22.25
23.25
23.50
25.00
26.50
28.00
29.50
30.75
32.75
34.00
36.00
39.50
45.00
USA
2511 Technology Dr, Suite 113/114
Elgin, IL 60124
800-877-3745
Fax: 847-783-5760
CANADA
2550 Meadowvale Blvd, Unit 3
Mississauga, ON L5N 8C2
888-336-7637
En Français: 888-368-8457
Fax: 905-542-7000
www.dormerpramet.com
Tap
Drill
Size
Alt.
Tap
Drill
Taper Pipe Taps - NPT
Unified Taps
0 - 80
1 - 64 UNC
1 - 72 UNF
2 - 56 UNC
2 - 64 UNF
3 - 48 UNC
3 - 56 UNF
4 - 40 UNC
4 - 48 UNF
5 - 40 UNC
5 - 44 UNF
6 - 32 UNC
6 - 40 UNF
8 - 32 UNC
8 - 36 UNF
10 - 24 UNC
10 - 32 UNF
12 - 24 UNC
12 - 28 UNF
1/4 - 20 UNC
1/4 - 28 UNF
5/16 - 18 UNC
5/16 - 24 UNF
3/8 - 16 UNC
3/8 - 24 UNF
7/16 - 14 UNC
7/16 - 20 UNF
1/2 - 13 UNC
1/2 - 20 UNF
9/16 - 12 UNC
9/16 - 18 UNF
5/8 - 11 UNC
5/8 - 18 UNF
3/4 - 10 UNC
3/4 - 16 UNF
7/8 - 9 UNC
7/8 - 14 UNF
1 - 8 UNC
1 - 12 UNF
1 - 14 UNS
1.1/8 - 7 UNC
1.1/8 - 12 UNF
1.1/4 - 7 UNC
1.1/4 - 12 UNF
1.3/8 - 6 UNC
1.3/8 - 12 UNF
1.1/2 - 6 UNC
1.1/2 - 12 UNF
1.3/4 - 5 UNC
2” - 4.1/2 UNC
Tap Size/
Pitch Form
1/16 - 27
1/8 - 27
1/4 - 18
3/8 - 18
1/2 - 14
3/4 - 14
1 - 11.5
1.1/4 - 11.5
1.1/2 - 11.5
2” - 11.5
2.1/2 - 8
3” - 8
D
R
7/16
37/64
23/32
59/64
1.5/32
1.1/2
1.47/64
2.7/32
2.5/8
3.1/4
6.30
8.70
11.10
14.50
18.00
23.25
29.00
38.00
44.00
57.00
67.00
82.50
Straight Pipe Taps - NPS
1/8 - 27
S
8.80
1/4 - 18
29/64
11.50
3/8 - 18
19/32
15.00
1/2 - 14
47/64
18.50
3/4 - 14
15/16
23.75
1 - 11.5
1.3/16
30.25
1.1/4 - 11.5
1.33/64 38.50
1.1/2 - 11.5
1.3/4
44.50
2” - 11.5
2.7/32
57.00
I.S.O. Metric Coarse
1.6 - 0.35
3/64
1.25
1.7 - 0.35
55
1.35
1.8 - 0.35
54
1.45
2 - 0.40
1/16
1.60
2.2 - 0.45
50
1.75
2.3 - 0.40
49
1.90
2.5 - 0.45
46
2.05
2.6 - 0.45
44
2.15
3 - 0.50
40
2.50
3.5 - 0.60
33
2.90
4 - 0.70
30
3.30
4.5 - 0.75
27
3.70
5.0 - 0.80
19
4.20
5.5 - 0.90
15
4.60
6 - 1.00
9
5.00
7 - 1.00
15/64
6.00
8 - 1.25
H
6.80
9 - 1.25
5/16
7.80
10 - 1.50
Q
8.50
11 - 1.50
3/8
9.50
12 - 1.75
Y
10.20
14 - 2.00
15/32
12.00
16 - 2.00
35/64
14.00
18 - 2.50
39/64
15.50
20 - 2.50
11/16
17.50
22 - 2.50
49/64
19.50
24 - 2.50
53/64
21.00
Tap Size/
Pitch Form
Tap
Drill
Size
61/64
27 - 3.00
1-3/64
30 - 3.50
1-5/32
33 - 3.50
1-1/4
36 - 4.00
1-3/8
39 - 4.00
I.S.O. Metric Fine
3 - 0.35
37
4 - 0.35
27
4 - 0.50
29
4.5 - 0.45
21
5 - 0.50
16
5 - 0.70
18
5 - 0.75
18
5.5 - 0.5
9
6 - 0.50
7/32
6 - 0.75
5
7 - 0.75
D
8 - 0.50
M
8 - 1.00
J
9 - 0.50
Q
9 - 1.00
O
10 - 0.50
3/8
10 - 0.75
U
10 - 1.00
T
10 - 1.25
11/32
11 - 1.00
X
12 - 1.00
7/16
12 - 1.25
27/64
12 - 1.50
Z
13 - 1.50
29/64
13 - 1.75
7/16
14 - 1.25
1/2
14 - 1.50
31/64
15 - 1.50
17/32
16 - 1.00
19/32
16 - 1.25
37/64
16 - 1.50
9/16
18 - 1.00
43/64
18 - 1.25
21/32
18 - 1.50
41/64
18 - 2.00
5/8
20 - 1.00
3/4
20 - 1.50
47/64
20 - 2.00
45/64
22 - 1.00
53/64
22 - 1.50
13/16
22 - 2.00
25/32
24 - 1.00
29/32
24 - 1.50
7/8
24 - 2.00
55/64
24 - 2.50
27/32
Alt.
Tap
Drill
24.00
26.50
29.50
32.00
35.00
2.65
3.65
3.50
4.05
4.50
4.30
4.25
5.00
5.50
5.25
6.25
7.50
7.00
8.50
8.00
9.50
9.25
9.00
8.75
10.00
11.00
10.75
10.50
11.50
11.25
12.75
12.50
13.50
15.00
14.75
14.50
17.00
16.75
16.50
16.00
19.00
18.50
18.00
21.00
20.50
20.00
23.00
22.50
22.00
21.50