Why are good metric micrometers so hard to find?

[Rex Walters]

my little 7x has carriage handwheel dials graduated in 0.25 mm and cross-slide and top-slide dials graduated in 0.025 mm

Apologies for an off-topic reply but I WISH the dial on the quill of my offshore mill was engraved with 0.25mm divisions instead of 0.001" divisions! One full turn of the handwheel moves the quill 2.5mm (0.0984").

Most of the time that thou and a half or so per rev doesn't matter, but every now and then I'd do some operation where I needed to move the quill over a substantial distance, and I'd wonder how I blew the dimension so badly. At least if it was marked in mm I'd know to do the math.

I use a DRO on X and Y on my mill, so I rarely blow those dimensions, but I still need to add a DRO to the quill of my square-column bench-top mill. The last cheap one I tried didn't have auto-off for the battery (to my immense annoyance).

I've also tossed a number of offshore 5C collets that were clearly made to metric sizes but considered "close enough" by some annoying person and marked with round decimal or fractional inches. One of my absolute pet peeves. For ER and other collets with a wider clamping range it really doesn't matter, but for 5C it really does. Line contact in a collet really sucks.

 

[Aaron_W]

I had no idea the metric idea went that far back on the domestic side.

I was surprised as well, I had expected the first full metric US cars would have been 1980s models, Taurus, Escort, K-Car etc.

 

[cleu]

I am looking to buy a set of micrometers for hobby machining, and I am trying to work as much in metric as possible. I would like be able to measure parts with more accuracy than I am able to machine them, so I am aiming to get a set of micrometers in the 0-250 mm range and 0.001 mm graduation (0-6'' and 0.0001'' graduation ). However, it seems impossible to find such a set at a reasonable price.

An imperial and mechanical set of 0-6'' and 0.0001'' graduation can be bought on Amazon for something like 120 dollars, but there is no metric equivalent available. Metric versions of these no-name Chinese sets are hard to find, but only at 0.01 mm graduations. Now, it seems to me that since 0.0001'' = 0.00254 mm, it should possible to find metric mechanical sets with at least 0.002 mm graduations. Yet I can only find 0.01 mm, and at that point, I may as well use a good caliper, since it can measure with that accuracy in a wider range and at much lower cost.

Digging further into the more expensive brands (Mitutoyo and Starret) it seems that something similar happens: Mitutoyo's 0-150 mm range set has 0.01 mm graduation, and Starret doesn't make any that are metric. It would seem that my only option is to buy electronic micrometers in the 0-6'' range and change the units. Here's an ilustration of the situation in McMasterCarr's catalogue, but it's like this everywhere I have looked.

Do you know if there are any providers of 0-150 mm mechanical sets with at least 0.002 mm graduation-accuracy?

Harbor Freight has 1” 2” 3” around $40 USA I’m sure I saw Metric also.

 

[SouthernChap]

Harbor Freight has 1” 2” 3” around $40 USA I’m sure I saw Metric also.

The title of the thread has the phrase "Good Metric Micrometers"

I know this thread has some YAGNI ("You Ain't Gonna Need It") messaging but when buying micrometers and dial indicators/dial test indicators (whatever the resolution), it's better to aim for the best one can afford.

Broadly speaking, better a good condition, second-hand Mitutoyo or other recognised quality brand metrology product than a new unbranded/re-branded cheap metrology product.

 

[kiwi_007]

Mitutoyo have made some awesome 0.001 metric micrometers, the 106 series, they were available in 0-25, 25-50, 50-75, & 75-100 they read to the 0.001 on a vernier on the barrel.
Saying that I've only ever seen the 0-25 & 25-50 for sale, usually on Ebay, if anyone has a 50-75 or 75-100 106 series for sale please let me know.
They also made the 101, 102 & 103 series with the vernier scale for 0.001 but I think these were only available in 0-25 & 25-50mm

I have the 106 & 102 in 0-25 & 25-50 the are 0.001mm

Also Moore & wright have made 0.001mm micrometers and 0.002mm.

While I have seen O.D mics with 0.001mm I have never seen a depth or internal mic with anything but 0.01mm
You can get bore mics to 0.005mm

 

[Rex Walters]

It was just pointed out to me that the wavelength of red visible light is only slightly smaller than 0.001 mm (400 to 700 nm per my understanding).

 

[WobblyHand]

It was just pointed out to me that the wavelength of red visible light is only slightly smaller than 0.001 mm (400 to 700 nm per my understanding).

Red light wavelength is between 600-700 nm. 400 nm is violet light. Getting into interferometer territory!

 

[SouthernChap]

It was just pointed out to me that the wavelength of red visible light is only slightly smaller than 0.001 mm (400 to 700 nm per my understanding).

Yep, just over half.

That explains the warm glow I feel, when using my Mitutoyo 0-25 mm 0.001 mm mic'...

 

[Pevehouse]

I am looking to buy a set of micrometers for hobby machining, and I am trying to work as much in metric as possible. I would like be able to measure parts with more accuracy than I am able to machine them, so I am aiming to get a set of micrometers in the 0-250 mm range and 0.001 mm graduation (0-6'' and 0.0001'' graduation ). However, it seems impossible to find such a set at a reasonable price.

An imperial and mechanical set of 0-6'' and 0.0001'' graduation can be bought on Amazon for something like 120 dollars, but there is no metric equivalent available. Metric versions of these no-name Chinese sets are hard to find, but only at 0.01 mm graduations. Now, it seems to me that since 0.0001'' = 0.00254 mm, it should possible to find metric mechanical sets with at least 0.002 mm graduations. Yet I can only find 0.01 mm, and at that point, I may as well use a good caliper, since it can measure with that accuracy in a wider range and at much lower cost.

Digging further into the more expensive brands (Mitutoyo and Starret) it seems that something similar happens: Mitutoyo's 0-150 mm range set has 0.01 mm graduation, and Starret doesn't make any that are metric. It would seem that my only option is to buy electronic micrometers in the 0-6'' range and change the units. Here's an ilustration of the situation in McMasterCarr's catalogue, but it's like this everywhere I have looked.

Do you know if there are any providers of 0-150 mm mechanical sets with at least 0.002 mm graduation-accuracy?

I was going to suggest electronic bitumen I see you have thought of that

 

[Oscar Lazo]

Mitutoyo have made some awesome 0.001 metric micrometers, the 106 series, they were available in 0-25, 25-50, 50-75, & 75-100 they read to the 0.001 on a vernier on the barrel.
Saying that I've only ever seen the 0-25 & 25-50 for sale, usually on Ebay, if anyone has a 50-75 or 75-100 106 series for sale please let me know.
They also made the 101, 102 & 103 series with the vernier scale for 0.001 but I think these were only available in 0-25 & 25-50mm

I have the 106 & 102 in 0-25 & 25-50 the are 0.001mm

Also Moore & wright have made 0.001mm micrometers and 0.002mm.

While I have seen O.D mics with 0.001mm I have never seen a depth or internal mic with anything but 0.01mm
You can get bore mics to 0.005mm

I was looking for some technical data on these series (mainly their accuracy), and I found this catalogue from Mitutoyo. They list the 103 Series, and the 101 Series. However, the 101 Series does not seem to include any metric mics. I purchased online a 101-116 mic that is claimed by the seller to be 25-50 mm with 0.001 (it looks very nice in the pictures) but doesn't mention accuracy. There are other 101-116 on ebay, but I can't seem to find technical data from Mitutoyo. The catalogue does give info on series 102, but no mention of series 106.

Does anyone know of a more complete catalogue? I found sellers online for all these series, but I would feel better if I could see the numbers from Mitutoyo.