I need to know the drill size or how to calculate it myself.
Jayme Gisbourne | 02/04/2021 16:44:13 |
11 forum posts | As a young lad I am blessed with the use of 60 degree threads that are now widespread. It’s easy to work out the drill size as all you have to do it minus the pitch from the OD and you get your drill size. Kind regards, J.
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Trevor Drabble | 02/04/2021 16:50:49 |
![]() 339 forum posts 7 photos | According to my Tracy Tools wall chart that is a UNEF thread , and their recommended tapping drill is 16.25 mm dia . |
not done it yet | 02/04/2021 17:40:14 |
7517 forum posts 20 photos | If you are blessed with the formula, why not just use it! Diameter is 11/16” = 0.69” (0.6875) Pitch is 1/24” = 0 0417 (0.04166) Diameter - Pitch = 0.6875 - 0.04166 = 0 646”
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DC31k | 02/04/2021 17:49:39 |
1186 forum posts 11 photos | If you type your topic title into Google, exactly as you have written it, you will find the answer to your query. E.g. https://www.gewinde-normen.de/en/unified-extra-fine-thread.html It will also suggest you use a drill sized at 16.6 of those new-fangled continental millimetric units rather than the bizarre not-in-any-standard-range imperial number quoted above. |
not done it yet | 02/04/2021 17:59:05 |
7517 forum posts 20 photos | For those unable to work out the metric size, 0.646 * 25.4 would provide the metric drill size. I expect the imperial drill size could easily be provided as a fraction, if really required. Just a bit more simple maths. |
roy entwistle | 02/04/2021 19:22:31 |
1716 forum posts | 83/128ths I think Roy |
Jayme Gisbourne | 02/04/2021 19:41:07 |
11 forum posts | Posted by Trevor Drabble on 02/04/2021 16:50:49:
According to my Tracy Tools wall chart that is a UNEF thread , and their recommended tapping drill is 16.25 mm dia . That’s great thank you! |
David Noble | 02/04/2021 20:30:24 |
![]() 402 forum posts 37 photos | Posted by roy entwistle on 02/04/2021 19:22:31:
83/128ths I think Roy David |
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