How do I measure the thickness of a coin?

I recently acquired an Eastern-mint Alexander the Great tetradrachm the seller described as "high relief".

It certainly seems high relief! But how can I quantify it? Does anyone here measure the thickness of their coins?

I presume I need some kind of calipers that won't scratch the coin. I have seen many plastic, steel and fiber calipers for sale online. The most common variety have the size "six inches" and I am not sure if the jaws will be big enough to reach across the entire coin, or even to the center. The digital variety seemed to be favored by collectors.

It seems straightforward (if the jaws are big enough) to measure the total thickness at the thickest part. Is that the standard way to go about it?

The obverse is in higher relief than the reverse. Is there any technique to measure the thickness of the relief on either side?

 

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Hope you don't get a smart___ remark like most all the ones I see on this site. But I would use a digital caliper.

 

Really? And how many have you seen?

 

I have both digital and non digital. I have a bigger digital type in my toolbox at work.
The jaws should be plenty big enough even for a sestertius.

 

I have metal calipers and do worry about scratching the coin since they are spring-loaded. I don't use it often and when I do I'm very cautious. It does not have adequate depth to reach the center of a some coins. It doesn't even have adequate length for coins larger than a stater. I bought it for measuring much smaller objects.

You can buy inexpensive digital calipers with greater depth, such as this one from Harbor Freight:

http://www.harborfreight.com/6-in-long-reach-digital-caliper-60248.html

 

digital
caliper

 

I'm not aware of anyone who has ever quantified the thickness of a coin (though I am sure some have). As it is not a standard concept I am sure you can just do as you want and that will be fine.

 

Well just to fit in. More than 1 and less than 100. Mostly to the new members.

 

I've used the same calipers for nearly 30 years. Cheap, brass, I think I paid maybe $2 or less back in the day. Brooklyn Gallery still has them for well under $6.94):

 

Either one will work.

 

I think CT is the most welcoming forum on the net. I'm not sure to just what you are referring. If it's the reaction to the influx of trolls here of late, then you have a false sense of this community.

 

For occasional use on coins the type Ken posted are good enough. If you want one slightly better, I say skip harbor freight. Sears has a wide selection. I would probably get a low-end Fowler caliper. They start at around $30-40. The next level up has the shockproof dial for ~$50. I've heard Starett's calipers really taper off in quality in the cheaper models. Harbor freight tools are typically junk.

 

As other have said I think digital calipers are the way to go.

I usually measure the depth of my coins because I like to store some of them in Air tites and the depth is usually the controlling dimension for ancients. As reference the above is a Tetradrachm so pretty decent size for an ancient and still plenty of room for a larger coin. Just be careful with the metal calipers so as not to scratch

 

Same guy. Multiple times.

 

Other than my own post, I have no idea what any of that is referring. But regardless, if you feel unwelcome here, I am sorry and I would like to welcome you to the best Ancients forum I know of.

 

Pickin and Grinin is actually a really nice and knowledgeable guy. If you stick around the forum you will see he typically gives really good advice. Sometimes members might seem short in their answers to typical questions but they still have good info to share if you're willing to stick it out.

As for the ancients group... now that's a cranky bunch.

...just kidding you guys are the best!

P.S. Welcome to the forum @lija66

 

My post does not belong in this thread.
End Quote.

 

ahhahahaaha! ve vill vock you!><

 

Back to the original question: I see no reason to use a calipers to measure the thickness of a coin. Relief would be the difference between the deepest and shallowest parts of a die but could not be measured significantly because of uneven striking. We rate 'High Relief' as a value judgement just as we do with 'Fine Style'. Many coins are thick but have low relief. I'm thinking here especially of jitals and many Indian/Islamic bronzes and billons. Coins can be high relief and thin flan or low relief and thick flan but both measure the same top to bottom.

Because of ancient coins rarely being perfectly round, the added accuracy of calipers is offset by the process of deciding which diameter to measure. I own calipers very much like Ken's but I measure diameter closely enough just laying the coin on a plastic ruler. Even that is not terribly significant since coins made without a collar can vary several millimeters just according to how hard they were hit.

For the record, the only reason I see to weight coins past 1/10th gram is to identify the specimen. No ancient minting authority made an effort to match their products to .01g. Most produced a range of weights as long as they got a specified number of coins out of a given weight of metal. Accuracy is wonderful but extra digits are not always significant.

 

I measure width of a coin with plastic calipers from 9:00 to 3:00 on the obverse:


This Maximian is 23.2 mm.