Micrometer setting standards

[grim_d]

Why are these always missing from used micrometers?

Is there someone swooping on them in the night and storing them in a box somewhere?

I don't understand it at all! I hope someone can shed some light here...

 

[brightspark]

there not all packaged with them even from new

 

[grim_d]

Even when there's a space in the box for them? How would one set ones mic then without a set of standards?

My only experience of a brand new mic was a Mitty 0-25mm which obviously doesn't need a standard, the instructions make it clear to use a standard where available to check calibration even when brand new. Pretty cheeky not to provide one!

 

[pedrobedro]

I've got one with mine, always wondered why it's 22mm

 

[Spark plug]

I've got one with mine, always wondered why it's 22mm

So you can check it at both ends of the scale.

For instance if I'm doing something really accurate I will check the mic with a slip guage near the size I'm working to.

 

[gordon stephenson]

We had several boxes of mitutouo outside mic's. the boxes contained a full set from 0-1" to 11"to 12" while we were sending a lot of other measuring gear to the local university metrology for testing, we sent the boxes of outside mic's as well ,they came back with half of the standards outside the spec required, only by small amounts but never the less not spot on,

 

[grim_d]

In an ideal world we would all have a lovely set of calibrated gauge blocks but it's a fair investment. I suppose it would be worthwhile however.

 

[brightspark]

99 percent of jobs wouldn't need that sort of accuracy and if your gear was bought from new and good quality and u looked after it is it needed

 

[grim_d]

My brand new mitutoyo mic was not calibrated from the factory.

Off to pick up 4 used m&w mics tomorrow with no standards. I wouldn't use them without checking calibration.

The degree of accuracy might not be required with gauge blocks but a set of them could well be cheaper than picking up individual standards depending how many mics you have, but if you're not going to calibrate your micrometers then why bother using them?

Unfortunately I am not from a part of the country with many great bootys, less so with decent tooling.

 

[Pete.]

My brand new mitutoyo mic was not calibrated from the factory.

Off to pick up 4 used m&w mics tomorrow with no standards. I wouldn't use them without checking calibration.

The degree of accuracy might not be required but using an uncalibrated micrometer is as good as eyeballing.

Of course it's not. You couldn't eyeball something to within the maximum possible error in a mic thread.

 

[brightspark]

I just check mine on various sizes of ground silver steel as I have 2 sets of metric and imperial mics an d 5 sets of calipers they all cant be wrong if they all read the same

 

[grim_d]

I was being facetious pete but you quoted my post before I changed it.

Anyway this isnt about setting mics or accuracy or what nots.

It's about who stole all the standards?! Apparantly the answer is the manufacturer.

 

[Pete.]

If you have no standard the easiest way to prove your mic is to check it against another. It's possible they both might be out but the odds on them both being out the same amount in the same direction are pretty damn slim.

Of course if they don't agree you're like a man with two watches but if they do you need not worry.

 

[brightspark]

If you have no standard the easiest way to prove your mic is to check it against another. It's possible they both might be out but the odds on them both being out the same amount in the same direction are pretty damn slim.

alleluia all these toolroom engineers what are they actually producing and is there machinery up to the mark as well

 

[grim_d]

It's not unreasonable to want my measuring equipment to be accurate regardless of my ability to use it or indeed its intended use. 

An uncalibrated peice of equipment could mean the difference between in or out of limits.

 

[brightspark]

i bought a dozen different size needle rollers all hardened and ground and can use them as test pieces. if my mics and calipers read the same that's good enough for me

 

[Pete.]

It's not unreasonable to want my measuring equipment to be accurate regardless of my ability to use it or indeed its intended use. 

An uncalibrated peice of equipment could mean the difference between in or out of limits.

But it IS unreasonable to expect a standard (or a tool, or a part) to remain calibrated at all temperatures. Standards are supposed to be on-size at 20 deg C, any variation will effect a change, that's why mics and standards have plastic pads to hold, to stop you heating them with your hands.

It's all a matter of degree - both in scale and in temperature.

 

[grim_d]

Absolutely, i'm not arguing to the contrary or in any way claiming I have the faintest idea of what I'm doing or talking about.

I definitely did not intend for the handbags to come out here, just a light hearted thread on the gnomes that steal standards.

Just like the gnomes that steal underpants.

Maybe it's me, is this why I have no friends?

 

[brightspark]

I thought it was women's underwear of washing lines

 

[gordon stephenson]

When you are happy that your mic's etc are ok, It's all down to the individuals touch, I have been quite surprised sometimes at the sizes some people obtain compared with my own, (which are always spot on of course) Boxed sets of slip gauges never handled with bare hands for really accurate stuff.