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METRIC CLEARANCE HOLE CHART
Metric clearance hole chart for metric bolts and screws according to ASME B18.2.8
Metric Clearance Holes Chart
Nominal Screw Size
Fit Class - Normal
Fit Class - Close
Fit Class - Loose
Nominal Drill Size
Hole Diameter
Nominal Drill Size
Hole Diameter
Nominal Drill Size
Hole Diameter
Min.
Max.
Min.
Max.
Min.
Max.
M1.6
1.8
1.8
1.94
1.7
1.7
1.8
2
2
2.25
M2
2.4
2.4
2.54
2.2
2.2
2.3
2.6
2.6
2.85
M2.5
2.9
2.9
3.04
2.7
2.7
2.8
3.1
3.1
3.4
M3
3.4
3.4
3.58
3.2
3.2
3.32
3.6
3.6
3.9
M4
4.5
4.5
4.68
4.3
4.3
4.42
4.8
4.8
5.1
M5
5.5
5.5
5.68
5.3
5.3
5.42
5.8
5.8
6.1
M6
6.6
6.6
6.82
6.4
6.4
6.55
7
7
7.36
M8
9
9
9.22
8.4
8.4
8.55
10
10
10.36
M10
11
11
11.27
10.5
10.5
10.68
12
12
12.43
Nominal Screw Size
Fit Class - Normal
Fit Class - Close
Fit Class - Loose
Nominal Drill Size
Hole Diameter
Nominal Drill Size
Hole Diameter
Nominal Drill Size
Hole Diameter
Min.
Max.
Min.
Max.
Min.
Max.
M12
13.5
13.5
13.77
13
13
13.18
14.5
14.5
14.93
M14
15.5
15.5
15.77
15
15
15.18
16.5
16.5
16.93
M16
17.5
17.5
17.77
17
17
17.18
18.5
18.5
19.02
M20
22
22
22.33
21
21
21.21
24
24
24.52
M24
26
26
26.33
25
25
25.21
28
28
28.52
M30
33
33
33.39
31
31
31.25
35
35
35.62
M36
39
39
39.39
37
37
37.25
42
42
42.62
M42
45
45
45.39
43
43
43.25
48
48
48.62
M48
52
52
52.46
50
50
50.25
56
56
56.74
Nominal Screw Size
Fit Class - Normal
Fit Class - Close
Fit Class - Loose
Nominal Drill Size
Hole Diameter
Nominal Drill Size
Hole Diameter
Nominal Drill Size
Hole Diameter
Min.
Max.
Min.
Max.
Min.
Max.
M56
62
62
62.46
58
58
58.3
66
66
66.74
M64
70
70
70.46
66
66
66.3
74
74
74.74
M72
78
78
78.46
74
74
74.3
82
82
82.87
M80
86
86
86.54
82
82
82.35
91
91
91.87
M90
96
96
96.54
93
93
93.35
101
101
101.87
M100
107
107
107.54
104
104
104.35
112
112
112.87
Supplements:
Thread Calculators and Charts
Metric clearance hole calculator
Reference:
Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H., (2016) .
Machinery's Handbook
. 30th edition. Industrial Press Inc.
Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H., (2012) .
Machinery's Handbook
. 29th edition. Industrial Press Inc.
ASME B18.2.8-1999, Clearance holes for bolts, screws and studs
