1804 half cent spiked chin scratches

[Coral Coin Man]

I have noticed on many 1804 half cents with a spiked chin there is a group of parallel scratches at about four o'clock on the obverse face.  Has anyone else noticed this?  I have not noticed this on other draped bust half cents. Is there a reason why a lot of the 1804 half cents with a spiked chin have these scratches?

[coinsandmedals]

If I remember correctly that is a die marker of the variety. Most of the 1804 spiked chin examples should have that present. The whole premise of the spiked chin variety is essentially rooted in a damaged die. Although I do not remember the exact explanation, I would hazard to guess this same logic would explain the lines you are talking about.

[DWLange]

Those are not scratches but rather die erosion lines. Here's an illustration:

https://www.ngccoin.com/variety-plus/united-states/half-cents/draped-bust-half-cents-1800-1808/11066/

[Conder101]

If you are talking about the lines in the field around 4 o'clock,those are from the treads of the bolt that was struck by the dies,  The head of the bolt created the spiked chine and the treads cut the lines in the field.