Bum micrometer?

[PerpetualStudent]

So I knew I'd need a micrometer for casting eventually. I bought one used at a gun show. Came home and tried to measure the diameter of my roundballs and I can't. It won't close down small enough. See Pic



That's it at full extension. By ruler it's about 3/4 of an inch gap.

My fault for buying used while ignorant, but can this be used for casting purposes? I thought maybe having a block and then using subtraction to get my data but I don't know if that will actually work.

If I just need to buy a new one, is a micrometer of this type useful to anyone? I could try to sell it and put the proceeds towards the new one.

Any information would be appreciated.

[Pawpaw757]

It looks like you have a 1" to 2" mic which will work fine for measuring handgun OAL. You may be better off finding a dial caliper, which has a wider range and just plain easier to use. I use mics but only because I was a machinist 100 years ago

[lefty o]

you want a 0-1" micrometer

[mdi]

Micrometers are made in 1 inch increments, 0"-1", 1"-2", etc. and the largest I've seen in use was a 5"-6". Your's appears to be a 1"-2". For reloading use a "1 inch mike" is all that's necessary and OAL is better measured with calipers (I much prefer dial over digital).

[EDG]

I collect mikes. I have 3 1 to 2" mikes. Despite some of them being 50 years old they are still like new because that size range is not used that much. My 0 to 1" mikes have had hard use for all of those years but due to careful handling they are still in nice condition.

[PerpetualStudent]

Thanks for the information guys. I really appreciate it.
Yeah for OAL, I think a dial caliper is what I'll get. While for casting I'll get a 0-1 mike. Now I know.

EDG, as a collector, how much does a 1-2" mike of japanese make tend to go for?

[jmorris]

Micrometers are more precise than calipers and they generally measure a much smaller range. Because of this they cost a lot more.

A 0-24” set of Starret calipers like this can cost many thousands of dollars. Each is a precision instrument and can only measure a range inside a single inch.



Any decent set will also include standards so you can quickly ensure their accuracy.

[john.k]

I have a Starret from WW2,which is 15-16" and navy marked,I was told they were issued for measuring the crankpins and journals of the engines in the Liberty ships.....Incidentally,notice Mr Morris has a set of testpieces with his mikes.....a testpiece is essential,and a mike without one ,and without its case is worth no more than a couple of bucks.

[smokeywolf]

I have a Starret from WW2,which is 15-16" and navy marked,I was told they were issued for measuring the crankpins and journals of the engines in the Liberty ships.....Incidentally,notice Mr Morris has a set of testpieces with his mikes.....a testpiece is essential,and a mike without one ,and without its case is worth no more than a couple of bucks.

The "testpieces" are actually referred to as "standards"

[EDG]

A nice Mitutoyo about $20 to $30.
Other brands about $10 less. The other brands such as NGK and Toyo Seiki will be slow sellers because potential buyers know little about them.

https://www.google.com/url?sa=t&sour...bBJU56XX0wnVb2

Thanks for the information guys. I really appreciate it.
Yeah for OAL, I think a dial caliper is what I'll get. While for casting I'll get a 0-1 mike. Now I know.

EDG, as a collector, how much does a 1-2" mike of japanese make




tend to go for?

[john.k]

I had a nasty shock with some of my jap mikes,the foam lining in the cases disintegrated and turned corrosive,pitting the plating on some of them.....the early Mitutoyos were OK cause they had metal boxes lined in velvet.I still have some of my very first mikes ,I think an Ambrose Shardlow 0-1" in the old tin spectacle case was given to me for my 10th birthday,the case is worn but the mike is still like new.

[Rick Hodges]

Whew, I read the title and thought there was a new instrument for measuring parts of the human anatomy.

[GOPHER SLAYER]

Rick, I think you would need a smaller set for guys who spend a lot of time in the cold, like Michigan for example.

[BNE]

Whew, I read the title and thought there was a new instrument for measuring parts of the human anatomy.

Me too! Glad I wasn’t the only one.

[DonMountain]

Micrometers are more precise than calipers and they generally measure a much smaller range. Because of this they cost a lot more.

A 0-24” set of Starret calipers like this can cost many thousands of dollars. Each is a precision instrument and can only measure a range inside a single inch.



Any decent set will also include standards so you can quickly ensure their accuracy.

I have been reloading for 40 years or so and have used a 6" dial caliper for measuring case lengths and a Starret 1" micrometer for measuring projectiles and case dimensions where I need more precise dimensions. But I drool over the set of micrometers and the lathe tailstock I can just barely see in the photos above from jmorris. Come on, can you show us the rest of the lathe!

[Pawpaw757]

JMorris, that picture really takes me back. I was a machinist at a local shipyard back in the late 70's and we had a set of those. Starrett makes some wonderful tools.

[Eddie17]

I to appreciate that set of mic’s. A dumb guestion, what would have to happen if a larger one was dropped. Would you retest against the standard, record a difference an continue to use.
Or send back to factory for recalibrateion? Just courious looking at that great set of tools!

[Pawpaw757]

Eddie17, My guess would be to check it against a standard (those rods in the drawer on the bottom of the box) and adjust as needed. If it was damaged, then a trip to the factory may be in order. We worked on prop shafts that were well over 24" diameter but I can't remember how we measured them. (sorry, don't mean to hijack the post)

[Eddie17]

Didn’t mean to hijack either. That is the just the biggest set of mic’c I’ve seen! Curious.

[ulav8r]

I to appreciate that set of mic’s. A dumb guestion, what would have to happen if a larger one was dropped. Would you retest against the standard, record a difference an continue to use.
Or send back to factory for recalibrateion? Just courious looking at that great set of tools!

Send it back. If the drop was enough to throw it off, the faces are likely no longer parallel.