Could someone please explain: where hairlines on coin can result in "Details" grade and where not? 0

[SilverStag]

Howdy folks. I collect coins from a small county of Holy Roman Empire. Most of the coins intended for circulation issued by theis county would be at least 300 years old today. The problem I'm facing is that many coins on the market from that era are cleaned or polished. What I do not understand, is that some obviously cleaned coins get numeric grade and some Details - cleaned. For instance, MS61: 

and UNC Details: 

I just got another 5 raw coins I plan to add to my collection, and I would say 4 out 5 them with visible chaotic hairlines on the fields. Will all those get Details grade, or there are some sort of criteria that grading companies follow when they decide which coin gets a nail in the coffin?

[kbbpll]

I'm perplexed by this as well. Sometimes I think it's die polishing lines versus cleaning hairlines, sometimes I think even a TPG fails to accurately make that distinction, sometimes I think they just decide to let it slide, sometimes it might not be the hairlines but dipping not done to their satisfaction. In your examples, the first one I see some lines that appear to continue on both sides of the reindeer and not on the reindeer, so I think of die polish. In the second example, most of the lines I see originate up against the inner ring of "denticles" but don't extend into the outer ring, and I don't see many crossing the reindeer, so I wonder if the grader messed up. Many of the lines in the second coin look raised to me, which would indicate die polish. Without the coins in hand, it's hard to tell.

[SilverStag]

Almost year after this post, time came to submit second batch of coins for grading. I wrote long email to NGC asking them to share guidelines in which cases and how Details grade is assigned, and even talked to NGC representative over the phone... but not much luck on both fronts.

Some information for those of you who will endup reading this forum threat while looking for information: it's possible for cleaned coin (especially old ones) to get numeric grade https://www.ngccoin.com/coin-grading/details-grading/, but so far there is no "1, 2, 3..." criteria has been published. Light old cleaning might get you numeric grade, harsher cleaning that affects appearance of the coin in question likely to result in details grade... unfortunately, I think at the end of the day it's up to NGC employee/s judgement to assign either or. While googling for information, I found this old forum thread with rare official NGC response on details grade which gives us some insight: 

 

I just wish NGC would post education videos or articles on Details grade similar to:

 

As for me personally, I ended up submitting next batch of coins hoping that light old cleaning will not get in a way of getting numeric grade.