Dial calipers

[steviebee]

Hi all,

Whats best for reloading? imperial or metric measurment? looking to go back in time and get a good set of manual calipers and wondered what would be the best format?

cheers

[grim_reaper]

Fractional. Most reloading measurement is in thousands of an inch so you might as well have tools that measure in thou rather than metric and convert the results. Unless you have everything in metric already in which case, as you were!

That is the nice thing about digital stuff, you can do either.

[acmsarh]

As above , You will find most of the reloading data and case length's are in imperial also do not buy a basic manual readout vernier get a dial or digital version they are easier to read.

[tacfoley]

As above , You will find most of the reloading data and case length's are in imperial also do not buy a basic manual readout vernier get a dial or digital version they are easier to read.

Yup, only European loading date handbooks are metric - very odd to see British calibres expressed in metric units, too.

Mind you, in all US loading books you'll see all the metric-designated calibres with dimensional data in imperial measurements, albeit decimal inches.

tac

[Black Beard]

Which are more accurate though, digital or mechanical? I am betting on the mechanical.

[Treebone]

Which are more accurate though, digital or mechanical? I am betting on the mechanical.

Mechanical vernier calipres rely on your ability to "see" and "read" a vernier scale, where as digital calipres present an actual numerical reading.
The resolution of the vernier scale on a calipre is +/- .002", on a digital it can be as low as .0005"
If your eyes are ****** then get a digital calipre, in fact even if your eyes are okay get one anyway its much quicker.

Ian.

[edbear2]

Which are more accurate though, digital or mechanical? I am betting on the mechanical.

As usual it depends on the quality. The very best analogue used to be Tesa (Swiss) brand, with very accurate racks and gears, But Verniers are not considered accurate in engineering compared to Micrometers etc.

This is a reply I found on another forum which explains it well, and save me some typing;

"I hope you don't confuse accuracy with resolution!

Accuracy has nothing to do with digital or analog. It is repeatability and certainty (region of trust) you get with that device. Also it should ideally not depend on the user (force etc.).
I personally don't trust a caliper beyond 0.025mm.
Those 0.025mm is what you can get with a vernier caliper (supposed I find my glasses). Be it digital or dial, its only a matter of convenience. The rest is only resolution or fake accuracy.

Bear in mind, that the Mitutoyo digital calipers do have an accuracy of 0.03mm over 150mm. The electronics inside are not steady, they do deviate from the zero error within a short distance (2.5mm or such, depending on the construction). The same is true for the gears inside of a dial caliper.

In short, digital or dial is only a means to display a value. Its not accuracy-related."



To The O.P, Get a set of Mitutoyo Digimatics off the bay, always several tidy used ones at good savings.
ATB, Ed