Sewing machine Threads - Thought to derive from the United States Standard form |
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| Nominal Diamater (ins) | Threads Per Inch | Major Diameter | Effective Diameter Screw & Nut (mm) | Minor Diameter | ||
| Screw (mm) | Nut (mm) | Screw (mm) | Nut (mm) | |||
| 5/64" | 64 | 1.984mm | 2.013mm | 1.726mm | 1.468mm | 1.554mm |
| 3/32" | 100 | 2.381mm | 2.339mm | 2.216mm | 2.051mm | 2.106mm |
| 3/32" | 56 | 2.381mm | 2.414mm | 2.086mm | 1.791mm | 1.889mm |
| 1/8" | 44 | 3.175mm | 3.217mm | 2.800mm | 2.425mm | 2.550mm |
| 9/64" | 40 | 3.572mm | 3.618mm | 3.160mm | 2.748mm | 2.885mm |
| 11/64" | 40 | 4.366mm | 4.412mm | 3.954mm | 3.542mm | 3.679mm |
| 3/16" | 32 | 4.763mm | 4.820mm | 4.247mm | 3.731mm | 3.903mm |
| 3/16" | 28 | 4.763mm | 4.828mm | 4.174mm | 3.585mm | 3.781mm |
| 15/64" | 28 | 5.953mm | 6.018mm | 5.364mm | 4.775mm | 4.971mm |
| 1/4" | 40 | 6.350mm | 6.396mm | 5.938mm | 5.526mm | 5.663mm |
| 9/32" | 20 | 7.144mm | 7.236mm | 6.319mm | 5.494mm | 5.769mm |
| 9/32" | 28 | 7.144mm | 7.209mm | 6.555mm | 5.966mm | 6.162mm |
| 5/16" | 18 | 7.938mm | 8.040mm | 7.021mm | 6.104mm | 6.410mm |
| 3/8" | 28 | 9.525mm | 9.590mm | 8.936mm | 8.347mm | 8.543mm |
| 7/16" | 28 | 11.113mm | 11.178mm | 10.524mm | 9.935mm | 10.131mm |
| 9/16" | 20 | 14.288mm | 14.380mm | 13.463mm | 12.638mm | 12.913mm |