WWI Era Army Mechanic Chevron - PFC?

[militbuff]

Is the attached mechanic chevron from the Pre or post WWI era?  Also, is it a PFC rank or is there a different name for it?

 

[Justin B.]

That is probably a PFC rated as specialist 6th class mechanic, 1920-WW2. Those were an unofficial but fairly common way to recognize increased specialist pay, from one rocker for 6th class to 5 rockers for 1st class. The rank was officially PFC.

 

 

[militbuff]

Thanks!  Definitely an odd looking chevron.