ISO Metric Screw Thread Chart
Nominal diameter
D (mm)
1st
2nd
choice
choice
Pitch
P (mm)
coarse
1
1.2
1.4
1.6
1.8
2
2.5
3
3.5
4
5
6
7
8
10
12
14
16
18
20
22
24
27
30
33
36
39
42
45
48
52
56
60
64
0.25
0.25
0.3
0.35
0.35
0.4
0.45
0.5
0.6
0.7
0.8
1
1
1.25
1.5
1.75
2
2
2.5
2.5
2.5
3
3
3.5
3.5
4
4
4.5
4.5
5
5
5.5
5.5
6
Bolt Head
Height
Flat size
H (mm)
A/F
(mm)
fine
0.75
1
1.25 or 1
1, 1.5 or
1.25
1.5
1.5
2 or 1.5
2 or 1.5
2 or 1.5
2
2
2
2
3
3
3
3
3
4
4
4
4
External
diameter
A/C
(mm)
2.125
5.5
6.4
2.925
3.65
4.15
7
8
10
8.1
9.2
11.5
5.65
7.18
13
17
15
19.6
8.18
19
22.1
10.18
24
27.7
13.215
30
34.6
15.215
36
41.6
19.26
46
53.1
23.26
55
63.5
46
84
96