Pete, Go to the Toolbox forum on the SW website. Joy Pineau has provided a very good answer to this kind of problem. There is a better way to do this. [QUOTE] I am trying to add BSP threads to the hole wizard, I can enter the[/QUOTE] data not problem, but When I go to put a new wizard hole onto a part, I get a lot of error messages.[QUOTE] I deleted the Ansi Inch data from the derived tables and have only added the 1" size BSP data. The data table is derived from Ansi Inch but the data that I have[/QUOTE] entered for BSP threads is over writing the Ansi Inch Data.[QUOTE] The hole wizard, for some strange reason, always starts with Ansi[/QUOTE] Inch, but is picking up the tap drill diameter size from the 1" BSP Thread tap drill diameter size data![QUOTE] This then try's to give a drill size bigger that the smallest Ansi inch tapped hole drill. The tap drill Diameter box is displayed in yellow, showing a size of[/QUOTE] 1.2602, this figure may be wrong, I am trying to remember what I did at work, :-S