Ebay mics...

[BGHansen]

I've got a set of Mitutoyo 0-3" at my mill (all off eBay), and Fowler 0-3" at my Grizzly 14 x 40 and Clausing 12 x 24 lathes. They're all the mechanical digital style. I have a couple of Mitutoyo 0-1" electronic digital and a Reid Tool 1-2" digital. All of the stuff came off eBay and works fine. I use regular micrometer standards as they're smaller than gauge blocks (and already came with the mic's). 1-2-3's should work depending on the accuracy of the block.

Bruce

 

[Bob Korves]

I've got a set of Mitutoyo 0-3" at my mill (all off eBay), and Fowler 0-3" at my Grizzly 14 x 40 and Clausing 12 x 24 lathes. They're all the mechanical digital style. I have a couple of Mitutoyo 0-1" electronic digital and a Reid Tool 1-2" digital. All of the stuff came off eBay and works fine. I use regular micrometer standards as they're smaller than gauge blocks (and already came with the mic's). 1-2-3's should work depending on the accuracy of the block.

Bruce

As Mikey stated above, the standards that come with mics are not considered accurate enough for calibration purposes. They are fine for checking to make sure the zero is still close, and are probably fine for most work. Gauge blocks are more accurate and also offer the possibility of testing odd spaces, like the fussy one you are measuring next. Comparative gauging between gauge blocks and workpiece while using a micrometer for the fit up feel only, ignoring the mic reading entirely, is a good way to get accurate results. You only need to trust the gauge blocks and your feel.

 

[Ebel440]

I've bought about 10 used mics up to 4" and only gotten one that needed to be calibrated. The same one has a sticky thread too but I've never tried to see if its damaged or just dirty. It only cost 3$ so not worth returning. So if you use my experience That's a 90 percent success rate of getting a good working micrometer. And I have less then 50$ in them.