How to use a Vernier caliper, in gif form.

"RamblinRover Luxury-Yacht" (ramblininexile)
03/11/2016 at 13:00 • Filed to: Essential Tools

Wikimedia Commons, image by J. A. Gaspar

Read out to the last line that the “0" is completely past, then add as the image shows - whichever number lines up with a number above. Magic!

On an inch thousandths vernier, it’s usually increments of .025 inches with a scale of 25 thousandths to add, not like the above. Dial calipers and digital calipers get sloppy and prone to zero errors, but a good vernier? Dunk it, drop it, get it dirty, and it laughs. Get you some.

DISCUSSION (17)

TheHondaBro > RamblinRover Luxury-Yacht
03/11/2016 at 13:03

Or just get digital calipers.

RamblinRover Luxury-Yacht > TheHondaBro
03/11/2016 at 13:05

With a shitty encoder so they read different numbers closing than opening? And you have to get watch batteries for? And can’t risk moisture? Nothx.

Smallbear wants a modern Syclone, local Maple Leafs spammer > RamblinRover Luxury-Yacht
03/11/2016 at 13:09

I love these. I spent quite a while messing around just to figure it out. And then proceeded to measure anything I could get my hands on.

RamblinRover Luxury-Yacht > Smallbear wants a modern Syclone, local Maple Leafs spammer
03/11/2016 at 13:11

There’s nothing quite like a really simple, effective, precise analog tool.

vondon302 > RamblinRover Luxury-Yacht
03/11/2016 at 13:31

So its just like a micrometer then.

Snuze: Needs another Swede > RamblinRover Luxury-Yacht
03/11/2016 at 13:33

I know how to read them, but how do they work? How does one of the numbers ALWAYS line up? I think they work on witchcraft!

RamblinRover Luxury-Yacht > vondon302
03/11/2016 at 13:35

A micrometer will be more precise, but with that you’re doing a full turn for every 25 thousandths you adjust. Slow. This enables you to get reliably within a thousandth or so, and fast. Absolutely you should use a mic on things like shims where a single thousandth can be important, but metal thicknesses, diameters, that kind of thing, a caliper is indispensable.

Telumektar > RamblinRover Luxury-Yacht
03/11/2016 at 13:35

The digital ones, the GOOD ones, go for crazy money last time I checked. I know all good Verniers are an expensive-ish tool, even the simpler ones.

Still my eyes (and my forgetful brain) would love for me to have a digital one... I don’t use them much anymore but it would be one of those nice, niiiice tools to have.

Wallaby > TheHondaBro
03/11/2016 at 13:42

I work in a bearing manufacturing plant and digital calipers get ruined by coolant and oils on our shop floor. Verniers are more or less immune to that nonsense. Also, digital calipers need to be checked for calibration every so often, a Vernier never goes out of calibration barring any physical damage. Of course we use MSI Viking stick gaging for anything past initial machining anyway because calipers of any kind aren’t accurate enough.

vondon302 > RamblinRover Luxury-Yacht
03/11/2016 at 13:42

I meant you read it just like a micrometer. Back when I was machinists nobody used calipers on anything with less than .005 in tolerance mics only still have my set of 0 to 8 in micrometers.

RamblinRover Luxury-Yacht > Snuze: Needs another Swede
03/11/2016 at 13:48

It *does* come off as magical, but the trick is fairly straightforward: it has to do how the two sizes interact. Taking the metric scales on the one in front of me, the main scale lines up with the lower scale’s units at 49 marks to 50 marks. Because sliding the lower scale over one mark lines it up again, every single point between as it travels between has to have a point where it lines up, because the maximum difference between any two “closest lines” is half of 49/50, or about 1% of the scale (if I have that right). As the lines travel, each will be between an upper and lower limit at all times, and one of them will be closer than the rest, because each has to cross over in turn. Sort of like making upper and lower limits in calc.

RamblinRover Luxury-Yacht > vondon302
03/11/2016 at 13:51

Kind of sort of like a micrometer. I have some good 1", 1 1/2", 2", 3" mics back at the house and some inside mics, but nothing huge. On the other hand, I did get a 20"+ vernier caliper at Northern Tool the other day, because why the hell not? Precise not so much at that size, but beats hell out of trying to use a measuring tape for diameters.

RamblinRover Luxury-Yacht > Telumektar
03/11/2016 at 13:56

I know there *are* really good digital ones. However, the usual excuse for getting a digital one is related to the reason that cheap horrible ones get bought. In other words “I don’t have time for this, give me something cheap I don’t have to learn how to read”. Hence comes tragedy - somebody buying a $14 plastic digital when a half-decent $20 stainless vernier could have been had. I did an assistant position at Georgia Tech in a new “Invention Studio” for people to work on ME senior projects in, and the caliper somebody scrounged for that lab? A plastic digital one with a skippy wheel. In the ME department. _

vondon302 > RamblinRover Luxury-Yacht
03/11/2016 at 13:59

20 in caliper thats cool I’d of picked it up to. Kinda ashamed I’ve never used a vernier in 13 years of machining.

RamblinRover Luxury-Yacht > vondon302
03/11/2016 at 14:06

The one I’ve got on my desk is a “Chicago Brand” one I bought out of Summit racing. Stainless, also available from Sears online, retails for about $25 either place. Not the best on the market, but perfectly serviceable. Strangely, the 20" giant aluminum one was cheaper, but it’s a carpenter-scaled caliper on the inch side, not a machinist one (1/64" or 1/128", not thousandths).

Telumektar > RamblinRover Luxury-Yacht
03/11/2016 at 14:37

Well, that’s waaay beyond what I was thinking for cheap... that’s like Chinese toy levels of accuracy. Around here cheap is a no-name metal vernier, still good but might not be 100% true... but for an engineering lab? I wouldn’t have thought it twice, you need a very good, accurate tool, not some chunk of plastic... that’s nuts.

Snuze: Needs another Swede > RamblinRover Luxury-Yacht
03/11/2016 at 14:49

I figured it was some sort of basic ratio of lengths. Still, witchcraft I tell you.