Thread Size Information
This information is from a now defunct website "Watchman" which fortunately has been archived on the Wayback Machine website. The original is a huge HTML table but also available as a spreadsheet. I have downloaded the spreadsheet and modified the layout slightly and made it available here for download along with a pdf version of the chart.
The table is 525 rows long and covers 24 different thread types. The image below shows what data is in the download.

Download Files
- Spreadsheet - in Open Document format (.ods) so should work in any supporting spreadsheet program like Excel or Libre Office
- PDF File - A standard format file that should open in your browser (10 pages)
- MEW Drilling & Tapping Equivalent Chart - 40MB
This is a copy of a wallchart produced by Magicalia (forerunner of MyTime Media) in Model Engineers Workshop. A bit smaller than the table described above. A standard one page PDF document, original is 570mm x 400mm Copyright I assume is MyTime Media - MEW Drilling & Tapping Equivalent Chart - 10MB
As above but resolution reduced to make a smaller download