As far as I'm aware, the "fractional read-out" type ones that Jim refers to are a relatively recent innovation -- not very prominent much more than, say,
5 years ago?
Regular old decimal-reading digital calipers have certainly been around for decades, although my recollection is that it wasn't until somewhere in the late '90s that they became inexpensive enough that your average, say, do-it-yourselfer homeowner could justify owning one.
In the early '90s a machine shop I worked at had just switched over their stock from the original slide rule-type calipers to dial calipers. If you were unlucky (lots of people working on a given day) you could still end up with the old ones; no one liked that!
Actually, I'm Australian. I know the digital equivalents of the regular fractional measurements off the top of my head, and can't imagine why anybody would want a display that displayed in sixteenths or sixty-fourths of an inch. I'm also pretty good at translating the old fractions of an inch measurements into millimetres.
And I still use my old vernier calipers when the digital unit is out of reach.
Well you see, Bil, in this country we never actually got around to fully converting over to the metric system, so there's an awful lot of dimensioning that's still done in fractions of an inch. :-) While certainly one can convert back and forth better fractions and their decimal equivalents, if you're having to do a whole lot of such conversions (and arithmetic with those values) it can start to become a bit error prone and life is then just easier and more reliable if you choose one system and stay with it. Sometimes, in the U.S., that system of choice is still fractions...
Is there any real difference betwen the $10 jobs you see at Harbor Freight and the one I bought years ago? Well, technically the company bought it, and I never gave it back - so it's mine now!!
Anyway, the one I have is a Mitutoyo Model CD-6"CS. (Code No.
IIRC, we paid nearly $175 for it. Maybe more.... A quick eBay search shows this model still brings bids over $100, and one as low as $5.
I guess my "real" question is not to brag about the size of my caliper, but whether these Harbor Freight ones are really any good? I've seen them on the shelves, and alwasy wondered...., but don't really have a need for a 2nd caliper, so,...
Did something happen in the past 5-10 years to really drop the price of these things, or we were just taken for a ride. BTW: The Mitutoyo caliper is very, very nice. And I would probably still buy it today at the same price and not feel too bad about it. It's very accurate - but then, I would guess they all are?? Right?
Yeah, they're "Ok". They don't have the nice smooth feel of a Mitutoyo but they measure okay. They go through batteries faster too. The digital interface is different from the Mit one (all the Chinese ones are pretty much the same) but few care about that.
Newer ones have much bigger displays, some are water/coolant proof, maintain their position through power cycling (probably because they don't really turn the power off- which sucks power) and some have fractional measurements (in case you can't recall what decimal corresponds to 13/32" or whatever).
China happened. And I guess the original patent ran out (Swiss, IIRC). You can still pay >$100 for better or larger sized Chinese or brand name (Mitutoyo, Fowler, Starett etc.) calipers.
No, they're all similarly crap, good for a thou or two at best. If you need to measure accurately, you should use a micrometer.
I picked one up to schlep around the office; amazing how handy it can be to have one in the drawer.
The feel is just a little rough -- not the finish, as such, but the feel while adjusting the jaws. Does seem to give good readings, though I've not compared it to a real standard, just some machined shims and feeler gauges (it was right on).
I'm guessing it's like the $5 multimeters from the same place; once the basic chipset and configuration was established, the cost of manufacture went way down.