Specifications of International Thread Standards

Conversion Inch-Fractions to Millimeters

Fraction
Inch
Decimal Fraction
Inch
Size
mm
Fraction
Inch
Decimal Fraction
Inch
Size
mm
1/1280.00781250.1981/640.0156250.397
3/1280.02343750.5953/640.0468751.191
5/1280.03906250.9925/640.0781251.984
7/1280.05468751.3897/640.1093752.778
9/1280.07031251.7869/640.1406253.572
11/1280.08593752.18311/640.1718754.366
13/1280.10156252.58013/640.2031255.159
15/1280.11718752.97715/640.2343755.953
17/1280.13281253.37317/640.2656256.747
19/1280.14843753.77019/640.2968757.541
21/1280.16406254.16721/640.3281258.334
23/1280.17968754.56423/640.3593759.128
25/1280.19531254.96125/640.3906259.922
27/1280.21093755.35827/640.42187510.716
29/1280.22656255.75529/640.45312511.509
31/1280.24218756.15231/640.48437512.303
33/1280.25781256.54833/640.51562513.295
35/1280.27343756.94535/640.54687513.891
37/1280.28906257.34237/640.57812514.684
39/1280.30468757.73939/640.60937515.478
41/1280.32031258.13641/640.64062516.272
43/1280.33593758.53343/640.67187517.264
45/1280.35156258.93045/640.70312517.859
47/1280.36718759.32747/640.73437518.653
49/1280.38281259.72349/640.76562519.447
51/1280.398437510.12051/640.79687520.241
53/1280.414062510.51753/640.82812521.034
55/1280.429687510.91455/640.85937521.828
57/1280.445312511.31157/640.89062522.820
59/1280.460937511.70859/640.92187523.416
61/1280.476562512.10561/640.95312524.209
63/1280.492187512.50263/640.98437525.003
65/1280.507812512.8981/320.0312500.794
67/1280.523437513.4943/320.0937502.381
69/1280.539062513.6925/320.1562503.969
71/1280.554687514.0897/320.2187505.556
73/1280.570312514.4869/320.2812507.144
75/1280.585937514.88211/320.3437508.731
77/1280.601562515.28013/320.40625010.319
79/1280.617187515.67715/320.46875011.906
81/1280.632812516.07317/320.53125013.494
83/1280.648437516.47019/320.59375015.081
85/1280.664062516.86721/320.65625016.669
87/1280.679687517.26423/320.71875018.256
89/1280.695312517.66125/320.78125019.844
91/1280.710937518.05827/320.84375021.431
93/1280.726562518.45529/320.90625023.019
95/1280.742187518.85231/320.96875024.606
97/1280.757812519.2481/160.0625001.588
99/1280.773437519.6453/160.1875004.763
101/1280.789062520.0425/160.3125007.938
103/1280.804687520.4397/160.43750011.113
105/1280.820312520.8369/160.56250014.288
107/1280.835937521.23311/160.68750017.463
109/1280.851562521.63013/160.81250020.638
111/1280.867187522.02715/160.93750023.813
113/1280.882812522.4231/80.1250003.175
115/1280.898437522.8203/80.3750009.525
117/1280.914062523.4165/80.62500015.875
119/1280.929687523.6147/80.87500022.225
121/1280.945312524.0111/40.2500006.350
123/1280.960937524.4083/40.75000019.050
125/1280.976562524.8051/20.50000012.700
127/1280.992187525.20211.00000025.400
Inch   Millimeter  
=