Dial Bore Gage Graduation and Range?
 

Been looking into gages...

is 0.0005 just fine or should I spend $ for a 0.0001?

Difference is ~$150 on a 1.4"-6" range.

What are the smallest and largest measurements one has to make with the bore gage on a rebuild?

Thanks,

-Michael

My set goes to .0005. you can estimate the next digit between the graduations so it is closer to .0002 or so. Remember the tolerances listed in spec books are given to the 0.01mm. Sometimes it only takes a few hundredths of a mm to be out of spec.

tolerance

.0001" = 0.0025mm
.0005" = 0.0127mm

If you are doing machine work, I would buy the .0001" resolution gauge. If you are checking used parts, or checking someone elses work the .0005" resolution gauge will be fine.

The accuracy of the average user of a bore guage will vary much more than .0001".

Unless you are doing work for the DOD, .0005" is fine.

I do question the need for a bore guage tho, it's just as accurate and cheaper to use an inside micrometer. Just make sure you check it with an OD mic that has been checked with a standard.

It takes a little more finess but if you know what yer doing it will provide accuracy down to about .0002" (that's the limit I hold my employees to, but they are very good at it).

Yes, setup is key. I have a cheap set of dial bore gauges. $40 on ebay. I use an outside mic to set the dial to "zero" on the required range. then double check a measurement with the mic set to the desired tolerance to make sure the dial gauge reads the same. My cheap set is surprisingly accurate if setup and used correctly.

Yea, I think you would get 5 different readings from 5 different people.. try it sometime