1920 P 1c Planchet Grooves

I've seen it before too, just don't know what it is.

could be remnants of roller lines. the angle of them on the obverse are the same as the ones on the reverse.

The rims look a little weak at K9 & K3 on both sides. What is the weight of this one?

I've always attributed this to age and oxidation of some metallic part of an improperly mixed alloy since it doesn't happen to all wheat cents.

BTW- 1920 is well known for having cents struck on foreign planchets. I found references to Argentina (5 Centavo), Columbia (2 centavo), Cuba (1 centavo), and El Salvador (1 Centavo). All seem to be made of 75% Cu & 25% Nickel so I'm not sure if or how this might play into your coin.

I took a couple more photos just for fun. You can see the lines on the rim pretty clear here so some sort of planchet damage for sure. You can also see an improper mix in the alloy. I would think this coin would be a little underweight with all that scraping and pitting but it is not. There are a lot of irregularities with this planchet and I do keep in mind what P55 said about this year having "off metal" errors.

Thanks Silviosi, that is a good guess.