A topic dedicated to calipers might be helpful. There have been a number of posts here and there around the forum, but they’re buried in other topics.
Here’s my quick (yeah right) take on calipers…
Anyone who might be looking to buy a set of calipers will probably notice that they have a pretty wide price range. That probably makes people wonder “is it worth it to buy the expensive ones, or are the inexpensive ones good enough?”.
To answer that question right off: yes, the cheap ones will probably be just fine.
And, to answer what I could see being a followup question: with my limited experience, I’d recommend taking the easy/expensive route, and buy these…
https://smile.amazon.com/Mitutoyo-500-196-30-Advanced-Measuring-Resolution/dp/B00IG46NL2/
With that said, the expensive ones do have some features that might be appealing enough to justify splurging.
Smoother operation - the grind on expensive calipers let them slide smoothly. Part of measuring with calipers is to use consistent pressure with measuring - it’s difficult to apply consistent pressure if there is too much friction between the sliding jaws.
Absolute positioning - this means you will rarely need to “zero” your calipers. To zero calipers, you typically move the two jaws together and press an “origin” or “zero” button. When you press the button, the LCD display will read “0.0000” (the number of zeros will vary). (Note: absolute positioning is something that will be an advertised feature. If the description of the calipers you’re looking at doesn’t have the word “absolute” in it, that set probably doesn’t have this feature.)
Tighter tolerances - less “play” or slop between the pieces will lessen unwanted movement which could manifest in imprecise measurements. Sometimes the value on the LCD will change while you’re holding the calipers, this may be caused by slop allowing the moving jaw to shift or twist slightly on the rail. This will be less of a problem with better-made calipers.
With all that said, I have a pair of calipers I bought from Harbor Freight pertineer 10 years ago. They’re 12"-ers and I believe they were $20 or so. The last time I compared the measurements between that set and my more expensive sets of calipers, the measurements from each were basically identical (as long as I zeroed-out the Harbor Freight calipers a couple times before doing any measuring. One thing I’ve learned the hard way is that they do may not read accurately when the battery is low (denoted by the LCD display blinking). Even though a measurement is visible between the blinks, you probably can’t trust it to be accurate.
On the other side of the coin, I bought a moderately-inexpensive set of “Woodstock” calipers from Amazon a few years ago (~$40 at the time). They were terrible. I sent them back (a rarity for me) because they sucked so bad. Sloppy, inconsistent zero, you name it. Bleh!
The last set I bought are from Brown & Sharpe/Tesa/Hexigon and they seem to be pretty nice. I like that they turn on automatically, unlike my Mitutoyos, but that might also mean the battery won’t last as long. They aren’t as smooth as my Mitutoyos though… Close, but not quite. And the user interface is weird.
This whole post is about digital calipers - the kind that has an LCD display that shows the measurement using, well, digits. The other common kinds of calipers, dial calipers and vernier calipers, might have some small advantages for some uses, but digital is probably the way to go for 99% of people.
AvE comparison between cheap and expensive calipers on YouTube (video contains naughty language): https://www.youtube.com/watch?v=WvszAb0Y0Ec