Unified Miniature Screw Threads Dimensions

Unified Miniature Screw Threads (ASME B1.10M-1997) which covers a diameter range of 0.30 mm to 1.40 mm extending the M-Profile and unified thread series that begin at 1.6 mm.

Unified Miniature Screw Thread Limits and Tolerances  
Limits of Size and Tolerances
External Thread Chart
Size
Designation		 Pitch,
mm		 Major
Diameter		 Pitch
Diameter		 Minor
Diameter
Max.
mm		 Min.,
mm		 Tol.,
mm		 Max.,
mm		 Min.,
mm		 Tol.,
mm		 Max.,
mm		 Min,
mm
0.30 UNM 0.080 0.300 0.284 0.016 0.248 0.234 0.014 0.208 0.187
0.35 UNM 0.090 0.350 0.333 0.017 0.292 0.277 0.015 0.247 0.225
0.40 UNM 0.100 0.400 0.382 0.018 0.335 0.319 0.016 0.285 0.261
0.45 UNM 0.100 0.450 0.432 0.018 0.385 0.369 0.016 0.335 0.311
0.50 UNM 0.125 0.500 0.479 0.021 0.419 0.401 0.018 0.357 0.329
0.55 UNM 0.125 0.550 0.529 0.021 0.469 0.451 0.018 0.407 0.379
0.60 UNM 0.150 0.600 0.576 0.024 0.503 0.483 0.020 0.428 0.396
0.70 UNM 0.175 0.700 0.673 0.027 0.586 0.564 0.022 0.500 0.464
0.80 UNM 0.200 0.800 0.770 0.030 0.670 0.646 0.024 0.571 0.531
0.90 UNM 0.225 0.900 0.867 0.033 0.754 0.728 0.026 0.642 0.598
1.00 UNM 0.250 1.000 0.964 0.036 0.839 0.810 0.028 0.714 0.666
1.10 UNM 0.250 1.100 1.064 0.036 0.938 0.910 0.028 0.814 0.766
1.20 UNM 0.250 1.200 1.164 0.036 1.038 1.010 0.028 0.914 0.866
1.40 UNM 0.300 1.400 1.358 0.042 1.205 1.173 0.032 1.056 1.000

Limits of Size and Tolerances
Internal Thread Chart
Size
Designation		 Pitch,
mm		 Minor
Diameter		 Pitch
Diameter		 Major
Diameter
Min.
mm		 Max.,
mm		 Tol.,
mm		 Min.,
mm		 Max.,
mm		 Tol.,
mm		 Min.,
mm		 Max,
mm
0.30 UNM 0.080 0.223 0.260 0.037 0.248 0.262 0.014 0.300 0.321
0.35 UNM 0.090 0.264 0.305 0.041 0.292 0.307 0.015 0.350 0.373
0.40 UNM 0.100 0.304 0.348 0.044 0.335 0.351 0.016 0.400 0.425
0.45 UNM 0.100 0.354 0.398 0.044 0.385 0.401 0.016 0.450 0.475
0.50 UNM 0.125 0.390 0.432 0.052 0.419 0.437 0.018 0.500 0.529
0.55 UNM 0.125 0.430 0.482 0.052 0.469 0.487 0.018 0.550 0.579
0.60 UNM 0.150 0.456 0.516 0.060 0.503 0.523 0.020 0.600 0.633
0.70 UNM 0.175 0.532 0.600 0.068 0.586 0.608 0.022 0.700 0.737
0.80 UNM 0.200 0.608 0.684 0.076 0.670 0.694 0.024 0.800 0.842
0.90 UNM 0.225 0.684 0.768 0.084 0.754 0.780 0.026 0.900 0.946
1.00 UNM 0.250 0.760 0.852 0.092 0.838 0.866 0.028 1.000 1.050
1.10 UNM 0.250 0.860 0.952 0.092 0.938 0.966 0.028 1.100 1.150
1.20 UNM 0.250 0.960 1.052 0.092 1.038 1.066 0.028 1.200 1.250
1.40 UNM 0.300 1.112 1.220 0.108 1.205 1.237 0.032 1.400 1.458
 

Supplements:

Reference:

  • ASME B1.10M-1997, Unified Miniature Screw Threads