review of my three new dial calipers from Enco

When I use dial calipers, I maintain the same thumb pressure, clean the
jaws, and zero often. I try to rock them into perpendicularity, and
measure with the same spot on the jaws each time. I check my accuracy
with pin gauges. I interpolate between the .001" hatch marks with my
eyes. My eyes can easily resolve .0002", but .0001" is harder.
0) My 8 year old Midway $20 Chinese 6" calipers can be trusted to .0002"
1) My new Enco $14 Chinese 6" calipers can be trusted to .001"
2) My new SPI $25 Chinese 6" calipers can be trusted to .0025"
3) My new Mitutoyo $72 Brazilian 6" calipers can be trusted to .0002"
The thing of interest was the $25 SPI looks like it is the same as the
$14, with nearly the same serial number sequence on the back. But the
SPI costs more and are not as good. The "SPI" name has been whore'd out
to Chinese junk.
Reply to
Clark Magnuson
Loading thread data ...
--Maybe SPI should change their name to CPI, eh? :-)
Reply to
steamer
Your dreaming if you think a dial caliper can resolve .0002"
Reply to
Tony
He may be confusing resolution with accuracy.
Reply to
Dave Hinz
Drop a zero and get real.
Wes
Reply to
Wes
When my cousin designed the electronics and software for some digital calipers, he got a patent and did a great job. I got a pair. The .0001" column is only a half a digit. It either reads .0005 or .0000". I called him up and told him I wanted the extra resolution, because I know how to control calipers and use it. He says that management did not want the resolution displayed if the accuracy was not there.
Reply to
Clark Magnuson
A very skilled hand can repeatably measure to .0002" with a good dial caliper. I once knew a machinist who used ordinary inside calipers (not measuring tools, just adjustable feelers) to "feel" inside dimensions and transfer to a mike. He said he could reliably do .0002. I didn't believe him until he proved it. He really could!
He was at least 60.
The issue is in getting a consistent "feel". Dial and digital calipers have a lot more "spring" to them than a mike does.
I don't trust calipers in my hands to better than .0005 on a really good day, or much better than .002 most days.
Reply to
Don Foreman
I've seen older Starrett dial calipers read several random gauge block stacks to better than 1/4 thousandth up to 6". The Phase II one I brought in for cal was barely within 0.001" .
Jim Wilkins
Reply to
Jim Wilkins
Have you adjusted the gibs on all of the calipers?
Mark Rand RTFM
Reply to
Mark Rand

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.