On Thu, 02 Jun 2005 13:48:48 GMT, "Mark"
wrote:

Forgive a possibly naive question, but does anyone make a tap to allow me to
thread a hole to screw in a bottle - perhaps a soda bottle size thread?
Thanks for any input.

I think a tap might be hard to find, but it's easy to make a bottle
cap on a lathe. Use Delryn (an acetyl engineering plastic) rod as
rawstock. I do it by hand rather than under power.

I think the threadform is closer to half-round than V or Acme. It
is on PET (plastic) bottles. I don't have a glass bottle to look at.