Craftsman valve grinder

[tom coffey]

I found this at the local flea market today.

 

[rsanter]

Valve lapper

 

[tom coffey]

Yeah and I gotta take it apart and see how round & round of the handle makes the shaft go back & forth 180 degrees. Inquiring minds need to know.

 

[wrenchguy]

It may have grinder written on it, back in the day that's what they were called.
"I believe" its because they were handcrank mechanical and more advanced than a spinning stick with suction cups on the ends. Now they accepted as lappers and using compound.