Bought my first micrometer

[am44mag]

Finally did something I've been meaning to do for a while and bought a micrometer. It looks to be pretty old, and I am definitely going to be reading that instruction booklet that came with it. I think I did pretty good for $32 on fleabay. Should be here Saturday. :D

I'm kind of amazed that the original owner kept EVERYTHING. From what I could find online, I believe that box design is from the 1920s-1930s.

https://i.ebayimg.com/images/g/Q9oAAOSwWqpav~Zp/s-l1600.jpg

[dale2242]

I have that very Micrometer .
Starrett are high quality...dale

[bob208]

I have mine I bought in 68. still in the box with the with all the papers. same for the last word indicator bought at the same time.

[DougGuy]

It's better than calipers, but very difficult to read in tenths of a thousandth. I would suggest a Mitutoyo Digimatic that would run you $3 to $12 more..

[lightman]

Thats a nice find. Now you just need to practice with it until you get comfortable with it.

[RED BEAR]

you can't go wrong with starret. get a standard or a steel dowel of known size to practice on and get the feel. i found that developing a feel is more important than the make of mic (no junck ones) . i personally always liked the feel of brown and sharpe but thats just me.

[CastingFool]

I also have that same micrometer, except mine has a ratchet on the barrel, to keep heavy handed "machinists" from using mikes as clamps. My dad bought it used, and used for a number of years as a machinist. In 1974, it became mine, when I started working as a machinist. Today, you will usually find it on my "reloading" bench, very close to my 6" dial caliper.

[Beagle333]

I have two of that same model. Great mics.

[murf205]

I have one just like it that belonged to my father in law who was an inspector at USS at the
Fairfield Works and a newer one with the ratchet. You cant be without one. You will get the "feel" for it quickly.

[Geezer in NH]

Great find and purchase you are going to be happy!!!! Mic's are so much better than just calipers

[smokeywolf]

All through my engineering and machining apprenticeship I used a Starrett 0 to 1" mike made in the 1930s. I have at least a half dozen 0 to 1" or 1.2" mikes now. I particularly like my B & S "slant line", my Tesa "Digit-Mike(s)" and my Mitutoyo "Quickmike(s)".

Another brand that was considered quite good back in the first half of the 20th century was Lufkin.

am44mag, as long as your mike zeros at 0", 1 inch and at say, .500", you did fine.

[am44mag]

It seems to work perfectly. You can tell it's been used a LOT, but it's smooth and was very well taken care of. I might have to get a magnifying glass though. My eye's aren't that great and those lines are hard to see.

Did my first pound cast (why I was wanting to buy it in the first place). I just grabbed an old Turkish Mauser to try it with. If I did everything right, and read the mic right, then it has a throat of 0.3259 and a bore of 0.3232 (ten thousandths place is an estimation, more on that in a sec). For an old gun like this that has been well used, I'd say that sounds about right (Especially with the HOT ammo those crazy Turks used). The rifling near the throat was kind of faint and you couldn't really tell where it started. It also seems like the throat was relatively short.

I'm kind of failing to see how I'm supposed to read ten thousandths. The instructions talk about a vernier scale, but there isn't one that I can find. It has a bunch of numbers on it though that I'm not sure what they are used for. They're between the two knurled parts (pic below).

https://uploads.tapatalk-cdn.com/20180601/a0b32e8b76b38e7919c9c9fbc839f267.jpg

[smokeywolf]

Your mike doesn't have a "tenth" scale on it. You just have to look at your thimble position and take your best guess.

[am44mag]

Your mike doesn't have a "tenth" scale on it. You just have to look at your thimble position and take your best guess.

That's what I figured.

[w5pv]

I have never wore one out there a adjustments from accuracy to thread slop that can be made.

[Ballistics in Scotland]

It's better than calipers, but very difficult to read in tenths of a thousandth. I would suggest a Mitutoyo Digimatic that would run you $3 to $12 more..

It is better than calipers for diameters of bullets, case heads etc., but the reloader doesn't need its level of accuracy for case or cartridge lengths. That one probably measures only in thousandths. The .0001 versions have lengthwise lines above the 0 to 9 numbers on the non-rotating sleeve, forming a vernier scale to measure tenths of the thousandths on the rotating thimble.

If they had digital micrometers in the 20s or 30s, I wonder how many it would have outlived?

I've got mine - a 2 to 3in. Starret, mint and in a wooden case, with the name LS Starret Co. Ltd., Jedburgh, Scotland. They opened there in 1958, and are still there. I don't know how much if any they actually make in the UK, but they once did. As far as you can tell, their Brazilian and Chinese operations seem to be factories genuinely established by themselves.

Probably the reason for mine being mint, is that it has been as much of a white elephant in someone else's workshop as it has been in mine. Also that I bought it for £2.50 on eBay, while the 1in. equivalent, the only one currently on their website, is £135.26 plus 20% tax. Oh well, the second-highest bidder, and there was one, did that.

I have other micrometers by the British Moore and Wright firm, including a point micrometer. I was able to identify the threads on a Francotte Martini action with that one, as 15/16in. rather than 23mm., by measuring from the roots of the female thread to the outside of the receiver. Also I once visited a small engineer's suppliers near the quayside in Glasgow, where engineering was invented, and in a tray of supposedly bargain priced dead stock found a mint tubing micrometer than has lain in stock for a decade or two. The bargain price turned out to be "Just take it and welcome", and although I have been a long-term customer, I was never a large or frequent one.

[MOA]

Nice find am44mag. All my digital micrometers an calipers are Starrett. My first one I got from my grandmother which was a 0-1 inch for my job at Bendix. I worked the 2nd shift at a tap and drill plant in New England as a OD grinder. I'm sort of prejudice about Starrett though, both my parents grew up in Athol, Ma, both worked at Starrett early on after high school until the war. My grandfather was a department head when he retired in 1965 with 45 years at the plant. Yup, can't go too wrong with Starrett tools.221425

[Dusty Bannister]

AM 44 mag comments "It has a bunch of numbers on it though that I'm not sure what they are used for. They're between the two knurled parts (pic below)."

If your barrel is marked like mine, they are fraction to decimal conversions.

[JonB_in_Glencoe]

All through my engineering and machining apprenticeship I used a Starrett 0 to 1" mike made in the 1930s. I have at least a half dozen 0 to 1" or 1.2" mikes now. I particularly like my B & S "slant line", my Tesa "Digit-Mike(s)" and my Mitutoyo "Quickmike(s)".

Another brand that was considered quite good back in the first half of the 20th century was Lufkin.

am44mag, as long as your mike zeros at 0", 1 inch and at say, .500", you did fine.

I would also like to add...

Am44mag,
If you don't have any standards or a standard.
https://www.qualitymag.com/articles/83880-quality-101-calibrating-micrometers
Us reloaders can get by, by using jacketed bullets, a .429 bullet will measure .429
and a .308 bullet will measure .308.
Jacketed bullets are what I used to 'check' the calibration of the first Mic I bought. Luckily my second Mic came with a neat little donut shaped standard, that was 1.000 in diameter and .250 thick.

[fast ronnie]

The tenths vernier will be on the back side of the barrel. Not all of Starret's mic's have the tenths graduation on them.
Does the mic have the carbide faces? A lot of them don't have that either, but if it does, it is a nice bonus. You can tell by looking at the tip of the spindle.

[KCSO]

Uh No a 308 bullet can measure from 307 to 308.5 depending on manufacture. If you read Water's Pet Loads he give the true diameters to all the bullets he loads and most are not to exact spec. A gauge block would be best but quality 1-2-3 will get you close. No sense buying a mike if you don't verify it you just a soon use a set of dial callipers.

[HangFireW8]

Hornady 44bullets run 0.430" not 0.429"; cheap bulk factory .30 bullets can often be between .307 and .308; Sierra makes the most affordable 30's that come in right at
0.308".

[country gent]

A few pin gages, gage blocks or even dowel pins will work. On a zero -1" a pack of cigarette papers close lightly on a paper and slide out a couple times this will clean the faces of grit and grime. The lightly close to your "feel" and check zero. Bullets can and do vary as to dia. Lapua made some 30 cal 170 grn rebated boat tails that were .309 and labeled as such. A 1/8" 3/16" 1/4" 5/16" up thru 1/2" by 1/16" increments wouldn't be very expensive from a local machine shop. Another way is to get together with 4-6 others and their 0-1" mikes and measure items then average the results this will give a very accurate idea of the items size. A feeler gage can be used for thinner small increments to check the mike.

[smokeywolf]

Mike standards can be had at pretty reasonable prices on "that auction site". country gent, as usual, mentioned something very useful. Gage pins and even dowel pins can get you dang close or at least in the ball park. Dowel pins will typically run between on-size and 50 millionths fat.

Because I have a number of machinist's chests, rollaways and service kits, I have not always had my mike standards or Jo-blocks with me on a particular job on a particular day. I have, a time or two, used precision pin gages, reamer-blanks, dowel pins or even end mill shanks to check my mikes.

[15meter]

The tenths vernier will be on the back side of the barrel. Not all of Starret's mic's have the tenths graduation on them.
Does the mic have the carbide faces? A lot of them don't have that either, but if it does, it is a nice bonus. You can tell by looking at the tip of the spindle.

Pretty unlikely it has carbide faces, not sure when Starrett started using carbide faces as an option but I know it was way past the 1920's.

Still a nice looking vintage mic.

[JonB_in_Glencoe]

Uh No a 308 bullet can measure from 307 to 308.5 depending on manufacture. If you read Water's Pet Loads he give the true diameters to all the bullets he loads and most are not to exact spec. A gauge block would be best but quality 1-2-3 will get you close. No sense buying a mike if you don't verify it you just a soon use a set of dial callipers.


Hornady 44bullets run 0.430" not 0.429"; cheap bulk factory .30 bullets can often be between .307 and .308; Sierra makes the most affordable 30's that come in right at
0.308".

Wow, I must be buying the right brands of 30 cal bullets :shock: I've never seen a .308 bullet THAT much over/under .308
But I don't doubt you two have...So, I guess I will no longer suggest using J-words for standards.


Yes, I agree a gauge block (Standard) is best.

[country gent]

With the dowel pins a 1" length or slightly longer gives enough to hold on to and measure easily. another trick is to coat 1/2" of one end in epoxy or a rubber material, even tygon or rubber tubing can be cut and pressed on this gives a nice "grip" to hold with, makes you measure the same end every time, and insulates the pin from oils acids in your skin along with body heat.
Starret and federal had digital mikes out for many years but they weren't electric but were mechanicals. three wheels were in the frame and geared to the thimble. Federal also had an Indicating mike that had a indicator tied to the anvil these could be set to a dimension and variations read on the indicator.
I have mostly browne and Sharp measuring tools. Michrometers are from 0-6" carbide faces slant lines and friction thimbles. But also have some starret mitoyo and others. My Mitoyo mikes are digital and read to 50 millionths (.00005) of an inch 0-1 and 1-2. On mikes unless used in a production line environment most will be good thru 3-4 owners LOL. My complaint with the electric digitals is it seems the batterys are always dying

[15meter]

With the dowel pins a 1" length or slightly longer gives enough to hold on to and measure easily. another trick is to coat 1/2" of one end in epoxy or a rubber material, even tygon or rubber tubing can be cut and pressed on this gives a nice "grip" to hold with, makes you measure the same end every time, and insulates the pin from oils acids in your skin along with body heat.
Starret and federal had digital mikes out for many years but they weren't electric but were mechanicals. three wheels were in the frame and geared to the thimble. Federal also had an Indicating mike that had a indicator tied to the anvil these could be set to a dimension and variations read on the indicator.
I have mostly browne and Sharp measuring tools. Michrometers are from 0-6" carbide faces slant lines and friction thimbles. But also have some starret mitoyo and others. My Mitoyo mikes are digital and read to 50 millionths (.00005) of an inch 0-1 and 1-2. On mikes unless used in a production line environment most will be good thru 3-4 owners LOL. My complaint with the electric digitals is it seems the batterys are always dying

To differentiate between the electronic and the mechanical Mike's the purely mechanical ones were usually called digit mikes. The electronic called digital. Mitutoyo was the best on battery life hands down. Starrett went through several generations of electronics before they started getting battery life to an acceptable level.