I never cease to be amazed at some of the insane threadforms some people design in, I also try never to be without a supply of sensible grub screws and their relevant taps... chrisc -----Original Message----- From: modeleng-bounce@xxxxxxxxxxxxx [mailto:modeleng-bounce@xxxxxxxxxxxxx] On Behalf Of Harry Wade Sent: Wednesday, November 21, 2007 03:41 To: modeleng@xxxxxxxxxxxxx Subject: [modeleng] Mystery thread I am presently converting a 14" Rockwell wood bandsaw for metal cutting and I need to match the thread of a grubscrew (missing) for a David Brown reduction gearbox, which I assume was made in the UK. The screw diameter measures .216" and the pitch is between a 24 and 28tpi but it is neither a 24 nor 28. The .216" is dead-on for a US #12 machine screw but it isn't that. Anyone have an idea what this thread might be? Regards, Harry 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. ________________________________________________________________________ This e-mail, and any attachment, is confidential. If you have received it in error, do not use or disclose the information in any way, notify me immediately, and please delete it from your system. ________________________________________________________________________ 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.