Guide pilot for Hall-Toledo valve seat grinders. (Like model EJ or VIP).  This is missing the 11/32 expanding collar, and will need a little work to replace the threaded rod (replacement included)

The round end installed has the correct .320 diameter, but the threaded end is broken off.  The round end will unthread if you grind the end flat, then you can install the .320 end on the included hex shaft.  Then you'll need to shorten the hex shaft and run a die over it to add the needed threads.  I've done this successfully several times on my own stock of HT pilots.

11/32  x  7/16" top.

Actual top measurement: .4360 - .4365 (measured in several places)

R11H