Specifications of International Thread Standards

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When trying to repair older pieces of machinery, establishing their threads can be pretty confusing at times.

In those cases (or just for kicks) perhaps the following personal page by Michael Prandl of Solingen, Germany can be of interest,
listing quite a few, namely 73 of them... International Thread Standards.

https://www.gewinde-normen.de/en/index.html

Note: The site is only for personal use, no unauthorized copying allowed,
it's NOT a searchable database, and Michael also explains why it isn't:

Attachment 35502

Half the fun of old and/or oddball stuff is figuring out what the threads are, always easier if they are to a recognised international standard.
Useful to be able to tell if they are one off's or special use as well.

Quote:

Originally Posted by DIYSwede

When trying to repair older pieces of machinery, establishing their threads can be pretty confusing at times.

In those cases (or just for kicks) perhaps the following personal page by Michael Prandl of Solingen, Germany can be of interest,
listing quite a few, namely 73 of them... International Thread Standards.

https://www.gewinde-normen.de/en/index.html

Note: The site is only for personal use, no unauthorized copying allowed,
it's NOT a searchable database, and Michael also explains why it isn't:

There is a program, FINDTHRD, on my page that has a searchable data base of some 400 threads. The contents of the associated text file provide more information...

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Andy Pugh, UK, has compiled a table of ~400 "standard" threads arranged in order of size (from 10 Whitworth instrument (0.010" dia.) up to 6" Gas) identified by type. A very handy tool for identifying 'mystery' threads one might encounter - especially when dealing with British equipment.

The list is a bit tiresome to search by hand if one is trying to identify an unknown thread. I wrote a program to search it using either major diameter or pitch as the search argument.
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The list itself is in ASCII form and is part of the archive so, if you want only the list itself, you can obtain it. (However, it's a lot more useful when machine searchable via the program.)

NB: All programs on my page are free but they were written back in the days of DOS so you will have to download and install a program like DOSBox to run them. That's not as bad as it sounds. There are a lot of excellent legacy DOS programs out there and being able to use them can be very handy.

Here's an example of a typical output from the program. I asked it to search for all the threads that had pitches within 1% of 32 tpi. The meaning of the various thread name acronyms is given in the data file that accompanies the program.

Code:

A - Find thread from diameter in inches B - Find thread from diameter in millimeters C - Find thread from pitch in tpi (threads per inch) D - Find thread from pitch in millimeters M - Display this menu Q - Quit (A,B,C,D,M,Q) ? Thread pitch [32 tpi] ? Allowable pitch error [1 %] ? Name, diam (in), pitch (tpi), diam (mm), pitch (mm) 123: 4-32 ASME , 0.1120, 32.0000, 2.8450, 0.7940 141: 6-32 ASME , 0.1380, 32.0000, 3.5050, 0.7940 142: 6-32 UNC , 0.1380, 32.0000, 3.5000, 0.7940 148: 0.148 GAS , 0.1480, 32.0000, 3.7590, 0.7940 151: 7-32 ASME , 0.1510, 32.0000, 3.8350, 0.7940 154: 5/32 CEI , 0.1563, 32.0000, 3.9700, 0.7940 161: 8-32 ASME , 0.1640, 32.0000, 4.1660, 0.7940 162: 8-32 UNC , 0.1640, 32.0000, 4.1660, 0.7940 168: 9-32 ASME , 0.1770, 32.0000, 4.4960, 0.7940 175: 3/16 CEI , 0.1875, 32.0000, 4.7630, 0.7940 176: 3/16 BSF , 0.1880, 32.0000, 4.7630, 0.7940 182: 10-32 ASME , 0.1900, 32.0000, 4.8260, 0.7940 183: 10-32 UNF , 0.1900, 32.0000, 4.8260, 0.7940 185: 0.196 GAS , 0.1960, 32.0000, 4.9780, 0.7940 187: 5 LOEW , 0.1969, 31.8000, 5.0000, 0.8000 188: M5 Coarse , 0.1970, 31.8000, 5.0000, 0.8000 195: 12-32 ASME , 0.2160, 32.0000, 5.4860, 0.7940 460: 1/4 UNEF , 0.2500, 32.0000, 6.3500, 0.7940 461: 5/16 UNEF , 0.3125, 32.0000, 7.9380, 0.7940 462: 3/8 UNEF , 0.3750, 32.0000, 9.5250, 0.7940 463: 7/16 UNEF , 0.4375, 32.0000, 11.1130, 0.7940 (A,B,C,D,M,Q) ?