[Cydrome Leader]

I just came across a shotgun bore brush package that states the thread for
the rod is 5/16-27.

Who the hell came up with 27 TPI? There's got to be a great story for
that- anybody know it?

[Tim Wescott]

On 03/05/2011 08:45 PM, Cydrome Leader wrote:
I just came across a shotgun bore brush package that states the thread for
the rod is 5/16-27.

Who the hell came up with 27 TPI? There's got to be a great story for
that- anybody know it?

Maybe there was some popular lathe in 1901 that had change gears that
made it easy to get 27 TPI.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

[Don Foreman]

On Sun, 6 Mar 2011 04:45:34 +0000 (UTC), Cydrome Leader
wrote:

I just came across a shotgun bore brush package that states the thread for
the rod is 5/16-27.

Who the hell came up with 27 TPI? There's got to be a great story for
that- anybody know it?

That's a pipe thread. I've also wondered how that came to be. Another
wierdo is the thread used on garden hoses and sillcocks, 1-1/16 x
11.5 TPI. My lathe can do both of these threads.