Internal Metric Thread Table Chart Fastener Sizes M 0.25 - M 8

ISO Hardware Engineering Data
Fastener and Screw / Bolt Design, Formula and Calculations

The following table chart are standard metric internal thread sizes M 0.25 - M 8 per. ANSI/ASME B1.13M-1995. These thread sizes and classes represent bolts and screws, as well, as other standard internal threads. Do not use these values for standard metric external thread design. All units in mm.

Metric Internal and External threads

Where:

H = P ( 31/2 / 2 ) = 0.866025 P
or
0.125H = 0.108253P

ISO Metric
Thread
Designation
Pitch
Metric Internal Threads
Specification Table
Tolerance
Class
Minor Dia
Pitch Dia
Major Dia
Tap
Drill
Min
Max
Min
Max
Min
Max
Basic
M0.25x0.075
0.075
6H
0.172
0.208
0.201
0.215
0.255
0.276
0.175
M0.3x0.08
0.08
6H
0.217
0.254
0.248
0.262
0.306
0.327
0.210
M0.3x0.09
0.09
6H
0.206
0.247
0.242
0.257
0.306
0.330
0.220
M0.35x0.09
0.09
6H
0.256
0.297
0.292
0.307
0.356
0.380
0.245
M0.4x0.1
0.1
6H
0.296
0.340
0.335
0.351
0.407
0.432
0.280
M0.45x0.1
0.1
6H
0.346
0.390
0.385
0.401
0.457
0.482
0.315
M0.5x0.125
0.125
6H
0.370
0.422
0.419
0.437
0.509
0.538
0.350
M0.55x0.125
0.125
6H
0.420
0.472
0.469
0.487
0.559
0.588
0.380
M0.6x0.15
0.15
6H
0.444
0.504
0.503
0.523
0.611
0.644
0.420
M0.7x0.175
0.175
6H
0.518
0.586
0.586
0.608
0.713
0.750
0.500
M0.8x0.2
0.2
6H
0.592
0.668
0.670
0.694
0.814
0.856
0.560
M0.9x0.225
0.225
6H
0.666
0.750
0.754
0.780
0.916
0.962
0.630
M1x0.25
0.25
6H
0.729
0.809
0.838
0.909
1.000
1.107
0.750
M1x0.2
0.2
6H
0.783
0.858
0.870
0.933
1.000
1.092
0.800
M1.1x0.25
0.25
6H
0.829
0.909
0.938
1.009
1.100
1.207
0.850
M1.1x0.2
0.2
6H
0.883
0.958
0.970
1.033
1.100
1.192
0.900
M1.2x0.25
0.25
6H
0.929
1.009
1.038
1.109
1.200
1.307
0.950
M1.2x0.2
0.2
6H
0.983
1.058
1.070
1.133
1.200
1.292
1.000
M1.4x0.3
0.3
6H
1.183
1.258
1.270
1.350
1.400
1.509
1.100
M1.4x0.2
0.2
6H
1.183
1.258
1.270
1.333
1.400
1.492
1.200
M1.6x0.35
0.35
6H
1.221
1.321
1.373
1.458
1.600
1.736
1.250
M1.6x0.3
0.3
6H
1.275
1.360
1.405
1.465
1.600
1.703
1.300
M1.6x0.2
0.2
6H
1.383
1.458
1.470
1.537
1.600
1.690
1.400
M1.7x0.35
0.35
6H
1.321
1.421
1.473
1.558
1.700
1.836
1.350
M1.8x0.35
0.35
6H
1.421
1.521
1.573
1.658
1.800
1.936
1.450
M1.8x0.2
0.2
6H
1.583
1.658
1.670
1.737
1.800
1.896
1.600
M2x0.4
0.4
6H
1.567
1.679
1.740
1.830
2.000
2.148
1.600
M2x0.25
0.25
6H
1.729
1.809
1.838
1.913
2.000
2.111
1.750
M2.2x0.45
0.45
6H
1.713
1.838
1.908
2.003
2.200
2.360
1.750
M2.2x0.25
0.25
6H
1.929
2.009
2.038
2.113
2.200
2.311
1.950
M2.3x0.45
0.45
6H
1.813
1.938
2.008
2.103
2.300
2.460
1.850
M2.3x0.4
0.4
6H
1.867
1.979
2.040
2.130
2.300
2.448
1.900
M2.5x0.45
0.45
6H
2.013
2.138
2.208
2.303
2.500
2.660
2.050
M2.5x0.35
0.35
6H
2.121
2.221
2.273
2.358
2.500
2.636
2.150
M2.6x0.45
0.45
6H
2.113
2.238
2.308
2.393
2.600
2.750
2.150
M3x0.5
0.5
6H
2.459
2.599
2.675
2.775
3.000
3.172
2.500
M3x0.35
0.35
6H
2.621
2.721
2.773
2.863
3.000
3.141
2.650
M3.5x0.6
0.6
6H
2.850
3.010
3.110
3.222
3.500
3.699
2.900
M3.5x0.35
0.35
6H
3.121
3.221
3.273
3.363
3.500
3.641
3.150
M4x0.7
0.7
6H
3.242
3.422
3.545
3.663
4.000
4.219
3.300
M4x0.5
0.5
6H
3.459
3.599
3.675
3.775
4.000
4.172
3.300
M4.5x0.75
0.75
6H
3.688
3.878
4.013
4.131
4.500
4.726
3.750
M4.5x0.5
0.5
6H
3.959
4.099
4.175
4.275
4.500
4.672
4.000
M5x0.8
0.8
6H
4.134
4.334
4.480
4.605
5.000
5.240
4.200
M5x0.5
0.5
6H
4.459
4.599
4.675
4.775
5.000
5.172
4.500
M5.5x0.5
0.5
6H
4.959
5.099
5.175
5.295
5.500
5.692
5.000
M6x1
1
6H
4.917
5.153
5.350
5.500
6.000
6.294
5.000
M6x0.8
0.8
6H
5.134
5.334
5.480
5.586
6.000
6.221
5.200
M6x0.75
0.75
6H
5.188
5.378
5.513
5.645
6.000
6.240
5.000
M6x0.7
0.7
6H
5.242
5.422
5.545
5.671
6.000
6.226
5.300
M6x0.5
0.5
6H
5.459
5.599
5.675
5.787
6.000
6.184
5.500
M7x1
1
6H
5.917
6.153
6.350
6.500
7.000
7.294
6.000
M7x0.75
0.75
6H
6.188
6.378
6.513
6.645
7.000
7.240
6.250
M7x0.5
0.5
6H
6.459
6.599
6.675
6.787
7.000
7.184
6.500
M8x1.25
1.25
6H
6.647
6.912
7.188
7.348
8.000
8.340
6.750
M8x1
1
6H
6.917
7.153
7.350
7.500
8.000
8.294
7.000
M8x0.8
0.8
6H
7.134
7.334
7.480
7.620
8.000
8.255
7.200
M8x0.75
0.75
6H
7.188
7.378
7.513
7.645
8.000
8.240
7.250
M8x0.5
0.5
6H
7.459
7.599
7.675
7.787
8.000
8.184
7.500

Related: