IMO, this is probably the best caliper you can find that isn't a high end machinist instrument that comes with a calibration certificate: https://www.amazon.com/gp/product/B001AQEZ2W
For coin use I would recommend the cheap carbon fibre ones from eBay. Not a metal jaw... it may be a really good caliper, but the metal jaw scares me.
You get what you pay for with precision instruments. If you want a measurement that is close enough, I'm sure the $20-$30 calipers will do the job. If you want accurate measurements for your lifetime, go buy a Fowler or Starrett.
..and if you are measuring in a manner where you leave a mark on a bar of soap(over-exaggeration obviously), you are over-torquing... This will give you an inaccurate measurement as well as destroy/mis-calibrate the tool. It's not a vice/pliers.
I use the $3 plastic ones from Harbor Freight sure they aren't high precision but they are probably accurate to .1mm which is typically good enough for coins. If you are doing machining then your going to want something a lot better. But at $3 it is accurate enough and if you damage it or lose it who cares, get another one.
You must be a machinist or a mechanical engineer, right? You don't need accuracy and repeatability better than .01mm over a small range for measuring coins. Many of the coins I measure (ancients) would vary more than that based on exactly where on the coin I measured.
lol, yep, I take my measuring devices vairy very seriously . As a general rule in life, I won't buy anything from harbor freight I plan on using more than once or twice. ...disposable Chinese junk.
Wow that was fast I never knew that many people would comment. Thanks. Main purpose is to measure coins of coarse gold and silver pandas to be exact.
I get to play with Starrett instruments all the time. They make great tools. For coins I use a China 6''. They work fine for coins but you really have to be careful. If I needed a caliper, I would buy a 4" plastic or composite. Less chance of damaging a coin.
I have a Starrett dial caliper and a Mitutoyo digital caliper and both are excellent quality. You can get creative and add a soft surface to the jaws and zero to this.
I have the $10 one from this seller. Most of us are not preforming scientific measurements, just getting relative sizes. I believe in good tools when you NEED good tools. Other than that, you are just wasting good coin money.
Measures in mm and 32nds of an inch http://www.wizardcoinsupply.com/product/plastic-millimeter-pocket-guide.html
