"Wild_Bill" wrote in message
...
Tim, when I posted this link before, in 2002, there was some speculation
that a tap this size could be used to make large valves such as those used
in oil fields.

--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html




That seems right Bill, on one of the photos "copes vulcan valve" can be seen
etched into the tap.

http://www.copesvulcan.com/products/valves.asp


I'll stick with small hand taps thanks!