Flat vs Grooved Coin Sides - Can Somebody Help?

[NamesJay]

I'm going through some half dollar pieces and I noticed some of the sides of the coins are very flat and smooth, and others have the more "normal" grooved edges.

 

Is there anything I should know about these different variations?

[bsshog40]

Well all halves back thru the Seated Liberty's are reeded ( or what you are calling grooved). I don't have anything older than a capped bust half in which they have a smooth edge but are lettered.

[19Lyds]

For the current copper nickel clad halves, the 100% copper core shows on the edges and is minimally covered by copper-nickel clading.

 

What occurs is that the soft copper cores hold most of the reeding and since they are softer than the clading, they wear smooth way before the coin has passed its useful life resulting in a coin which has a smooth edge..

[richbeat]

If you're talking current half dollars, a LOT of the edges on them were worn smooth from a lot of slot machine usage.