Can anyone tell me why clockmakers went to such an unusual thread size to be used on chime rods? The taps [6.5]are very uncommon, but do make a very tight seat.
Is there anything else out there that can be used for chime rods and get the same results-same vibration, etc.
Thanks!

Sir Greg,

Sure am not able to answer you properly.
I would like to find the answer myself. As you say, I cannot recall finding any rods ever becoming loose or falling out. The constant vibration perhaps has demanded that the threads are modified to allow insertion and never removal. Is it possible the mmale are different that the female threads to permitt a "locking" effect?

Moses Gingerich
Waxhaw NC

Thanks for your reply, Moses. The only other application I have seen using that thread size is surgeons who use 6.5 mm threads on their bone screws, so I guess they must use that thread knowing they won't loosen off.We couldn't have legs falling off, could we.
It would nice to be able to get the broken ones out easier though.
Thanks!