Metric micrometer what t buy?

I have more than enough measuring instruments from when I was working, I actually sold three digital Mitutoyos for an average of £60 each as they were not being used. I did buy a 25-50mm micrometer for only £14 new not so long ago, it was NOS made in the DDR, which means it predates the unification of Germany. It is top quality with instructions, a length bar and a nice box. Worth looking on ebay in case there are any left.

Electronic Digital ones do. Don’t think the vernier ones have two optional scales.

Electronic Digital ones do. Don’t think the vernier ones have two optional scales.

I think the tri scale callipers only give an approximation of the nearest fraction .

Yes a digital calliper or mic will convert inch to metric and visa versa but i have yet to see one that can give the sum of a series of fractions and then convert that to a decimal number !

I am currently working on an engine that all of the dimensions on the drawing are given in fractions so i have to first convert these to decimal then add them together to find the length of a part etc - Major PIA !

The app - Fractions calculator does this with ease and gives the decimal equivalent automatically .

There are digital mics going for £40 upwards, I have no personal experience of one, they may be ok for home use.

I've just bought 0-25mm and 25-50mm Starretts from Amazon. They were around £35-40 each and it seems prices fluctuate, so perhaps I go a bargain with both. What I will say though. is that they are MUCH easier to read than the cheap one I had off eBay. I misread that a number of times on the 0.5mm markings. I've not misread the starretts at all so far. Well worth every penny.

What is the problem?

A digital calliper (every home workshop should have at least 6" one) has a converter built in - pull out the slide to the size you have, press the imp/mm button and there is tha answer. You can set the slide to one thou easily, if you are working to tighter tolerances than that, you do not heed any advice from here.

DiodeDick.

The only 'new' mic I've ever purchased was many years ago and is a large barrel 0-25mm one by an East German (DDR) company (it mentions Carl Zeiss on the back page of the booklet) and it is not only very well made but also very easy to read - each graduation being 0.01mm. It couldn't have been very expensive back then (as I didn't have much money) but it is excellent quality. I've looked after it and it's still in mint condition - mainly because unfortunately I don't tend to use it very much.

All my other mics are Imperial in various sizes up to 6" and are most are made by M&W. They were all used (and in very tatty boxes) but have cleaned up very well. I've now calibrated them (using slip gauges) and they are occasionally very useful (e.g. useful to have but not essential). I also have a very old 1" Starrette mic which is basically my Workshop mic and (I'm afraid) just gets used and abused. I don't throw it around but it knows the inside of my pocket quite well - which is always handy...

I can move between Imperial & Metric quite easily because I can still multiply & divide by 4 just about ( 1mm is about 40thou, 4 thou is about 0.1mm etc). My machines are all Imperial and I find 'thous' easy to work with (e.g. they are simple numbers between 1-999). I must admit, I'm not so fluent with fractions though...but a friend of mine was a wizz at adding a long list of them up but he'd done it all his working life.

So - Old East German (DDR) mics are very nice to have, used (good quality) mics can be great value - and get whatever type (Imperial or Metric) that will make you happy. Works for me!

Regards,

IanT

I picked up one of these Moore & Wright basic range (200 series) micrometers when at a show from Machine DRO.

Current price is around £26.00 so quite affordable. All I can say is it works only odd thing to get used to is that the big blue collar on the barrel is the ratchet rather than the more usual small knob on the end. I must admit I find reading the metric mike more of a challenge than the imperial one. At least you don't have to keep putting batteries in it!

John

Old East German (DDR) mics are very nice to have

I am also a fan of DDR made KS Feinmessungsfabrik Suhl measuring equipment - I have 0-1", 1-2", 0-25mm, 25-50mm oustide micrometers and a 0-100mm depth mcirometer set. All have a good feel & are easy to read - on a par with or better than Mitutoyo IMO. That said, my "go to" 0-1" micromter that lives in it's wood box on the lathe suds tray is a Polish made one that was a "freeby" with a Model Engineer or MEW subscription many years ago !

G & M Tools had a lot of KS micrometers for sale some time ago & still show a NOS DDR production 0-25 outside micrometer on their website today for £15 + Vat.

The company survived reunification and is still in business :

**LINK**

I don't find metric mics as easy to read as Imperial ones - too easy misread & get 0.5mm out (a problem that my workplace colleagues also face). I always do a quick check of the micrometer anvils with a digital caliper now to guard against this.

Nigel B

(edit for spelling)

Edited By mgnbuk on 16/11/2019 11:24:41

1 - 2" ? Surely 0-2" I have 0 - 1", 0 - 2", 0 - 3", and 0 - 4 "

I could never see the point of a 1/2 - 1" either

Roy

Again, thanks for the comments to date.

I'm thinking I'll stick my first thoughts of a second hand quality brand type. It's interesting that very few replies have said anything about the Chinese cheapies, but somebody must buy them - perhaps to use as G clamps...

I'll have to be extra careful reading the metric mic then Nigel, something I hadn't thought about to be honest!

I'm glad it's not just me, I have the same problem, particularly with my one small internal mic , which is metric.
Recently my cheapo Aldi/Lidl digital caliper had the battery door fall apart, so I picked up a spare new boxed unit off the shelf; I'd bought it for conversion to a digital height gauge.
It checked out fine against my 1" analogue mic test piece.
I then measured the bore of a small grinding wheel, with both the internal mic and the digital caliper and made the arbour to suit, also using the caliper to check the mic for a mis-read.
Yes a rattling fit 0.5mm out, the actual bore was 13+mm not 1/2"

On further investigation, the inside jaws on this caliper mis-read by 0.5mm; the one with the dodgy battery door was spot on, and I'd not thought to check its replacement.
Just something to beware of with cheap verniers.

Bill

The position of the thimble is often adjustable and positioning it just where you prefer it can be helpful in avoiding confusing which mark you are on

Mike

1 - 2" ? Surely 0-2" I have 0 - 1", 0 - 2", 0 - 3", and 0 - 4 "

Nope - 1-2", 2-3", 3-4" etc. for me every time.

I hate,loath & detest replaceable anvil outside micrometers - a "kludge" solution to a problem if ever there was one. More often than not useless from an accessibility point of view, trying to get (say) a 4" frame with the 0-1" anvil in place into many situations is just not possible. The 0-6" Mitutoyo set that my previous employer had was even worse.

My current employer has a Mitutoyo 0-300mm set, but that is 12 individual micrometers from 0-25 through to 275-300 in a fitted box - a far better (though more expensive initially) solution.

To each their own, though.

Nigel B

Not doubting you Roy (well, I guess I am a bit) but I've never seen those. A 4" long thimble must be a sight to see. Could you post pictures (or a link)?

There are varieties available which don't have a 4" thimble.

This Starrett works as a 0-1" through to a 5"-6", so almost fits the description.

It's getting a bit tired now but is accurate at both ends, but the 2"-3" and 3"-4" misread by one and two thou respectively.

I don't know if it was originally supplied with a set of reference bars.

See also THIS LINK

Bill

Edited By peak4 on 16/11/2019 23:22:54

Henry, I will let you know I have ordered a Chinese one for a grand total of £7.00. A friend bought his for £6.00 and says it is fine and more than accurate enough. Will be interesting to see what turns up.

Ron

Cheers Ron, I'm particularly interested in the feel and thus the accuracy. If it isn't consistent and smooth running as you adjust onto the work piece I don't see how accuracy and repeatability is maintained. Looking forward to your observations...

The only mikes i own are a cheapish set from chester hobby about 4 years old now (so not the set currently shown)

How accurate? Wel without other methods of comparison it's impossible to say. Repeatability is likely more down to me that the tool whch i consider consistent within my abilities - in other words if I spin the thimble down too fast it'll go an extra 0.01mm or so. When I;m trying to work to better tolerances (should it be justified) then I check with the test bar before that session and often have to adjust by 0.01mm or so. But then do I always wait until everythign in the shed has reached ambient temp when I've put the woodburner on? Can I machine on the mill to that accuracy anyway along a piece of material? It's quite disappoining to check the thickness along say a 4" length of material and find it varies by a few 1/100th mm and more cheering to hear the likes of Oxtool make ocassional comments that suggest I'm not alone.

On the same topic - how many folk check accuracy of their DRO with test bars or wait until the mill has warmed to temp on table etc. I doubt the DRO scale ex[ands exactly like every other table component.

Fortunately none of that matters for the bits I make which fit together rather than having to fit a part made elswhere and inaccessible.

To quote Clint Eastwood "A man has to know his limitations"

It's a screw and a rachet and two anvils - after that it's individual appreciation of feel and bragging rights.

pgk