I believe the loose definition (today) is anything .020" or less is considered fine pitch. What is considered "standard" pitch is .050". 
But next month, it could be anything less than .010". 
In 2019, there is a conspiracy underfoot to make it anything less than .005"!
Just kidding, but it is not defined anywhere, to my knowledge.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ron Feyereisen
Sent: Thursday, September 06, 2018 9:29 AM
To: [log in to unmask]
Subject: [TN] PTH Fine-Pitch Definition

Hi everyone,

Is there an established definition for what would be considered a PTH fine-pitch component?

Is any pitch of 1.27mm or less considered to be the definition?

Thoughts?

Thanks,
Ron