how much over or underweight does a coin have to be for it to become an error?

ClosedLoop

is it common for planchets to vary in weight?


For example, a 1983 cent should weigh 2.5 grams. what would be an exceptable weight variation (+ or -) before this
coin is considered to be an error?

Does it become an error? Or deos it have to be struck on a different planchet or metal before it becomes an error?

Or am i just nuts to actually think of this question?

GoldenEyeNumismatics

As I recall official Mint tolerances are 2 or 3%, but I think 10% is probably a safer percentage to be considered a true error.

fugnchill

Mint tolerance is .3 if I remember correctly but it also depends on the coin (year and physical appearance). If it is .5 then I start looking closer. With your example of the 1983 Lincoln, It should be 2.5 grams but there are known "error" examples at 3.1 (copper planchet). So, 2.5 + .5 = 3.0. If the coin looks normal as in thickness/diameter and weights 3.0 grams then I'd be sending it off for authentication.

So to answer your questions: Yes planchets vary in weight. Yes it's an error since that planchet wasn't suppose to be used for that coin...(an oops). The year is a factor whether or not it's an error or variety...Large cents were made with large or small planchets (thick/thin). This is just my opinion and some may not agree but this is how I view it.

Oh ya your last question: 'Or am i just nuts to actually think of this question?'. Nope! This is the exact question I made to come to my conclusion.

Lestrrr

19Lyds

Interesting.

I have two 1973-S 40% Business Strike coins.

Mint Weight = 24.6 grams
Coin Number 1 = 25.3 grams (The Heavy Weight)
Boin Number 2 = 23.2 grams (The Light Weight)

The Light Weight is weakly struck for a 40% Business strike in that annealing marks can be seen near the edges. You rarely ever see annealing marks on a 40% Business Strike coin.

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Light Weight to the right.

PerryHall

If it's outside mint specified tolerances, it's an error but that doesn't necessarily mean that it has any additional value.

frnklnlvr

The one on the right is definitely thinner.