Coin scale/Calipers?

Anyone have a recommendation for an accurate cheap coin scale? My wife received one for our wedding but it rounds to the nearest gram and I would like to have one that measures to the hundredth of a gram if possible.

Also, I bought a cheap-o gray caliper for measuring ancients. I think I paid $4 for it. I was happy until I realized that my measurements were not matching the ones the sellers were listing. I took a picture of the item in question because I was sure I was crazy.

As you can see though, this old ruler of mine is more accurate and the difference is significant. What am I doing wrong? Reading it incorrectly? Is it just junk? Help!

 

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If you have a Harbor Freight Tools there or online can get a decent digital for around $10. Any jewelry supply store.

 

Wizardcoinshop.com has scales to 0.01g tolerance. Great people. Agreed on calipers. I have a good one that serves well for coins at $20. Hit a tool surplus for a decent one for coins...$10-$20USD

 

Calipers might be useful, I suppose, but I have used my trusty ruler to measure my coins for many years. I simply hold the ruler over the coin and eyeball it. I typically match the seller's measurement, and rarely disagree by more than 1 mm.

As for scales, my wife bought me a Dillon Precision digital scale from CNG for Christmas many years ago. It works quite well. The problem is it has a 100 gram weight limit. That makes it useless for larger Aes Grave, which I collect. So, my advice in buying a scale is to consider what you collect and the maximum weights you are likely to encounter. Scales all have weight limits, and you need to pick a scale with that context in mind.

 

Carausius is right about scales for weight. I use a digital my wife uses on gemstones not sure the brand but 10 years ago it was around $30-40 it was given to me from a friend. My answer was based on the photo & assumed the OP had merely mistakenly stated scale vs caliper.

 

My scale is a 200g max x 0.01g tolerance. Handles all of my Aes Grave (No As or complete Signatum... Yet)... And I spent approx $40USD...

I enjoy calipers as we use them a lot in a manufacturing environment. Habit.

 

I have an iGaging IP54 digital caliper and a TBBSC digital scale.

The caliper is essentially the best digital caliper you can buy without going to a high end Mitutoyo caliper (i.e. the kind of instrument that comes with a calibration certificate and will run you multiple hundreds of dollars). It's an absolute origin caliper, and I don't think I've ever had to zero it, except when I changed the battery. Great piece of kit!

The scale has a weight limit of 50g, so bigger bronzes are out of the question for it, but it works great for denarii and pretty much all modern coins. I like the milligram precision.

Edit: FYI everyone, the links are not affiliate links, so feel free to click away.

 

I just use a ruler to get the diameter. My scale is accurate to 0.01 grams and cost me 20.00.

 

I missed this part. The problem is you bought a $4 plastic piece of junk, unfortunately. You don't have to get all fancy and digital like I did, but at least get a metal instrument.

 

That's one of the reasons I never bought a caliper - the good ones are made of metal, and I've no interest in tempting fate by holding a pointed metal object against my precious coins! My plastic ruler works fine, is cheap, and poses no risk to my coins.

 

A metal caliper poses no risk when used properly to measure the diameter of a coin. I probably wouldn't use it to measure thickness, for fear I'd slip, but measuring diameter is totally safe.

 

So far, I have not had any probs with my metal calipers...I measure diameter and thickness... just take care in measuring.

 

I agree. I have a fancy digital caliper and it is made of steel and has spring action and sharp edges. Once in a while I use it for coins (for tiny coins or if I want a more accurate measure of thickness), but most often I just put the coin against a clear plastic ruler.

 

Nicholasz219,
For measuring I use a 6 inch steel pocket ruler rhat you can get at any hardware store for a couple of bucks. The non-inch side is graduated in millimeters and I just eyeball the short and long diameters, listing both in any written description. My backround includes some precision metal fabrication and I think that dealers sometimes over do it a bit with measurements to the hundredth of a millimeter, especially since ancient coins are rarely round.

My scale is an old powder scale but I wouldn't recommend that route because its units of measurement are in grains (an older pharmacutical unit) and you'll end up having to convert ro grams.

Hope this helps

 

Yeah, I'm not always the most coordinated guy, and there's actually very little reason to measure the thickness of a modern coin, anyway. I might measure thickness of an ancient coin, but, again, I find very little reason to do so. Unless I end up getting one of those crazy Aegean turtle coins or something, I think weight and diameter will be good enough for me.

 

I collect ancients. Some of which I collect are Aes Grave, Ptolemies, and other thick coins. I like knowing thickness as it can be a defining aspect of the coin.

 

The photo is not large enough for me to read correctly but it seems to be close to 2.2 cm so I'm missing something.

I have two digital scales that do not agree. I bought the second because it came with two calibration weights which do not weigh the same to .01. Calibration procedures centering on a 100g weight is not ideal for weighing a 5g coin. I also note that using a scale in a room with a ceiling fan or furnace running will not be accurate. Irather gave up on that last digit because I'm not willing to pay for a scale on which it would be significant. As it is, I weigh three times minimum before I will accept a reading as worth writing down.

 

I am lucky enough to have access to scales with a tolerance equal to the number of zeros in the price.

 

Weighing multiple times is absolutely the correct thing to go. As for the air current issue, my scale has a cover for just such a purpose. You do need to use it on a hard, level surface, however. It's calibration weights are 2x20g, which seems to work well enough given the coins I weigh.

I've seen pictures of some of your coins. You must work in a lab and have access to an analytical balance.

 

The accuracy of my scale seems to vary depending upon what time of day it is ...




... when it starts to act wonky, we take a break and go eat some potato chips