micrometer v. calipers

[DonSmithnotTMD]

I have to measure the outside diameter of my 1911 barrel for a new barrel bushing. Since I can't find my Dad's micrometer and don't know where to borrow one, I was wondering if I could use calipers instead.

[Zef_66]

I have to measure the outside diameter of my 1911 barrel for a new barrel bushing. Since I can't find my Dad's micrometer and don't know where to borrow one, I was wondering if I could use calipers instead.

I am not familiar enough with the 1911 to know if calipers will measure it accuretly enough. All depends on the tolerance of the final part. Micrometers typically can measure ±.001. Calipers on the other hand are more along the lines of ±.003-.004. For the bushing, I would think you would need to use a set of micrometers. But that is just my opinion.

[Xringshooter]

If you have access to a digital caliper it should do you what you need. Digitals will accurately read to +/- 0.0005 or better nowadays.

[Zef_66]

If you have access to a digital caliper it should do you what you need. Digitals will accurately read to +/- 0.0005 or better nowadays.

Ron, You are correct that they can read to that accuracy. But the problem that we find at work is that people don't use them correctly. Even using digitals, some people can get wildly different numbers. All depends on how you hold the part and calipers.

But I guess if you can't work calipers correctly, micrometers will be foreign and end up with even worse measurements.

Carry on then!

[CommonHighrise]

Any good caliper set will have a calibration pin, usually 1" in length, that you can use to verify the calipers accuracy right before you measure the part. Should keep you within 5 tens.

If you're not getting reliable measurements that way, you can go by most any garage that is a state PA inspection station. They will have calibrated 0-1.00" micrometers that you can use to double check, probably for the price of a soda/coffee.

[DonSmithnotTMD]

I am not familiar enough with the 1911 to know if calipers will measure it accuretly enough. All depends on the tolerance of the final part. Micrometers typically can measure ±.001. Calipers on the other hand are more along the lines of ±.003-.004. For the bushing, I would think you would need to use a set of micrometers. But that is just my opinion.

That's what I was wondering.

Any good caliper set will have a calibration pin, usually 1" in length, that you can use to verify the calipers accuracy right before you measure the part. Should keep you within 5 tens.

If you're not getting reliable measurements that way, you can go by most any garage that is a state PA inspection station. They will have calibrated 0-1.00" micrometers that you can use to double check, probably for the price of a soda/coffee.

You must be some kind of genius or something. I never thought of that. And we drove by half a dozen garages today. grrr!

[ungawa]

Calipers are better for measuring a round object than micrometers - in the respect that micrometers requires more skill for this. Take several measurements at different radial positions.

Digital calipers are not more ACCURATE than mechanical micrometers, although some are more SPECIFIC when compared in a cheap price range.

[summersux]

For anything that needs to be accurate, measure it with a micrometer. If you don't have one, a garage or preferably a machine shop will have a set you can use.

[Xringshooter]

If you do not have a mic or caliper, guess what, unless you personally know the people in a garage or machine shop (and they know you know how to use a mic or caliper) you will not get them to lend you one by just walking in and asking. Mechanics are very possessive of their personal tools. Tell them what you need and they will probably do it for you (offer to pay them). Best bet is just to take it to your local gunsmith and have him measure it for you. That said, if you are doing this type work for yourself you should already have the basic tools which would include both a mic and a caliper.

[knight0334]

.001" accurate mic's are like $20-$40 and are at most gunshops that sell reloading gear. Just buy one..


Digi's suck and are not as accurate(too much float), but are _unt-hair close enough for most things.