Hi Peter, yes that would be a great help. Thank you ALL for your help, 1/2 whit seems to be the one. but it would be nice to have a copy of the page. Im glad i asked, for some strange reason I was thinking if 1/4 whit only because had a die of that thread! I can't believe Martin E would leave out sutch an important dimention even when they have been re-drawn, but think i can at a push work it out now. Thank you all again keith. MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.