|
Tap size |
NF/NC UNF/UNC |
Threads per inch |
Basic major dia (inches) |
Basic effective dia (inches) | Basic minor dia of ext. threads (inches) | Basic minor dia of int. threads (inches) |
Drill size |
|
0-80 |
UNF |
80" |
.0600" |
.0519" | .0447" | .0465" |
3/64" |
|
1-64 |
UNC |
64" |
.0730" |
.0629" | .0538" | .0561" |
#54 |
|
2-56 |
UNC |
56" |
.0860" |
.0744" | .0641" | .0667" |
#50 |
|
2-64 |
UNF |
64" |
.0860" |
.0759" | .0668" | .0691" |
#50 |
|
4-40 |
UNC |
40" |
.1120" |
.0958" | .0813" | .0849" |
#43 |
|
4-48 |
UNF |
48" |
.1120" |
.0985" | .0864" | .0894" |
#42 |
|
5-40 |
UNC |
40" |
.1250" |
.1088" | .0943" | .0979" |
#38 |
|
5-44 |
UNF |
44" |
.1250" |
.1102" | .0971" | .1004" |
#37 |
|
6-32 |
UNC |
32" |
.1360" |
.1177" | .0997" | .1042" |
#36 |
|
6-40 |
UNF |
40" |
.1360" |
.1218" | .1073" | .1109" |
#33 |
|
8-32 |
UNC |
32" |
.1640" |
.1437" | .1257" | .1302" |
#29 |
|
8-36 |
UNF |
36" |
.1640" |
.1460" | .1299" | .1339" |
#29 |
|
10-24 |
UNC |
24" |
.1900" |
.1629" | .1389" | .1449" |
#25 |
|
10-32 |
UNF |
32" |
.1900" |
.1697" | .1517" | .1562" |
#21 |
|
1/4-20 |
UNC |
20" |
.2500" |
.2175" | .1887" | .1959" |
#7 |
|
1/4-28 |
UNF |
28" |
.2500" |
.2268" | .2062" | .2113" |
#3 |
|
5/16-18 |
UNC |
18" |
.3125" |
.2764" | .2443" | .2524" |
F |
|
5/16-24 |
UNF |
24" |
.3125" |
.2854" | .2614" | .2674" |
I |
|
3/8-16 |
UNC |
16" |
.3750" |
.3344" | .2983" | .3073" |
5/16" |
|
3/8-24 |
UNF |
24" |
.3750" |
.3479" | .3239" | .3299" |
Q |
|
7/16-14 |
UNC |
14" |
.4375" |
.3911" | .3499" | .3602" |
U |
|
7/16-20 |
UNF |
20" |
.4375" |
.4050" | .3762" | .3834" |
25/64" |
|
1/2-13 |
UNC |
13" |
.5000" |
.4500" | .4056" | .4167" |
27/64" |
|
1/2-20 |
UNF |
20" |
.5000" |
.4675" | .4387" | .4459" |
29/64" |
|
9/16-12 |
UNC |
12" |
.5625" |
.5084" | .4603" | .4723" |
31/64" |
|
9/16-18 |
UNF |
18" |
.5625" |
.5264" | .4943" | .5024" |
33/64" |
|
5/8-11 |
UNC |
11" |
.6250" |
.5660" | .5135" | .5266" |
17/32" |
|
5/8-18 |
UNF |
18" |
.6250" |
.5869" | .5568" | .5649" |
37/64" |
|
3/4-10 |
UNC |
10" |
.7500" |
.6650" | .6273" | .6417" |
21/32" |
|
3/4-16 |
UNF |
16" |
.7500" |
.7094" | .6733" | .6823" |
11/16" |
|
7/8-9 |
UNC |
9" |
.8750" |
.8028" | .7387" | .7547" |
49/64" |
|
7/8-14 |
UNF |
14" |
.8750" |
.8286" | .7874" | .7977" |
13/16" |
|
1-8 |
UNC |
8" |
1.000" |
.9188" | .8466" | .8647" |
7/8" |
|
1-12 |
UNF |
12" |
1.000" |
.9459" | .8978" | .9098" |
59/64" |
|
1 1/8-7 |
UNC |
7" |
1.1250" |
1.0322" | .9497" | .9704" |
63/64" |
|
1 1/8-12 |
UNF |
12" |
1.1250" |
1.0709" | 1.0228" | 1.0348" |
1 3/64" |
|
1 1/4-7 |
UNC |
7" |
1.2500" |
1.1572" | 1.0747" | 1.0954" |
1 7/64" |
|
1 3/8-6 |
UNC |
6" |
1.3750" |
1.2667" | 1.1705" | 1.1946" |
1 13/64" |
|
1 1/2-6 |
UNC |
6" |
1.5000" |
1.3917" | 1.2955" | 1.3196" |
1 11/32" |
|
1 3/4-5 |
UNC |
5" |
1.7500" |
1.6201" | 1.5046" | 1.5335" |
1 35/64" |
|
2-4.5 |
UNC |
4 1/2" |
2.0000" |
1.8557" | 1.7274" | 1.7594" |
1 25/32" |