|
Bolt
Size
|
Threads Per Inch (TPI)
|
|
Coarse Thread
UNC
|
Fine Thread
UNF
|
|
#2
|
56
|
-
|
|
#3
|
48
|
-
|
|
#4
|
40
|
-
|
|
#5
|
40
|
-
|
|
#6
|
32
|
-
|
|
#8
|
32
|
-
|
|
#10
|
24
|
32
|
|
#12
|
24
|
-
|
|
1/4
|
20
|
28
|
|
5/16
|
18
|
24
|
|
3/8
|
16
|
24
|
|
7/16
|
14
|
20
|
|
1/2
|
13
|
20
|
|
9/16
|
12
|
18
|
|
5/8
|
11
|
18
|
|
3/4
|
10
|
16
|
|
7/8
|
9
|
14
|
|
1
|
8
|
14*
|
|
1-1/8
|
7
|
12
|
|
1-1/4
|
7
|
12
|
|
1-1/2
|
6
|
12
|
* 12 TPI is the UNF standard, however 14 TPI is more common in
actual use.
|
|
Bolt
Size
|
Thread Pitch
|
|
Standard
|
Fine
|
Extra or Super Fine
|
|
2
|
.4
|
-
|
-
|
|
2.5
|
.45
|
-
|
-
|
|
3
|
.5
|
-
|
-
|
|
4
|
.7
|
-
|
-
|
|
5
|
.8
|
-
|
-
|
|
6
|
1.0
|
-
|
-
|
|
7
|
1.0
|
-
|
-
|
|
8
|
1.25
|
1
|
-
|
|
10
|
1.5
|
1.25
|
1
|
|
12
|
1.75
|
1.5
|
1.25
|
|
14
|
2
|
1.5
|
-
|
|
16
|
2
|
-
|
-
|
|
18
|
2.5
|
-
|
-
|
|
20
|
2.5
|
-
|
-
|
|
