Milton
US Veteran
I am looking for a one inch vernier micrometer that 1.will not cost a bunch and 2. will actually be accurate to 0.0001 inch.I borrowed a chinese one and was not impressed.
Suggestions ?????
Suggestions ?????
Vernier Micrometer
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Moonman
Member
.0001 is tough to get a FEEL FOR, and for accuracy down that close you really need to be in a temperature controlled atmosphere. (68 degrees + or - 1/2 of a degree). The part should be cleaned of all oils, hand or otherwise, and have rested in that atmosphere for a period of 24 hour first. Usually when accuracy that close or finer it's done with electronic measurements. Some folks seem to think that MICROMETERS are C-CLAMPS when they try to use them.
DWalt
Member
I have one, but it is far from new - a 1" Starrett vernier. I seldom need the 0.0001" precision, but I have a few times. Depending on your budget, you might check on eBay for used ones. The 1" micrometer I use most is a no-name 0.001" non-vernier. No trick to estimate to 0.0005 or less even without the vernier. No idea who made it, but it works OK for me.
OP
Milton
US Veteran
Thanks guys! Yes I know for the most part 0.0001 inch is a stretch.I just do not want one that is inaccurate.
I was looking at the Starrett site and found a Starrett T436.1XFL-1 that looked good.Anyone familiar with this mic?
I was looking at the Starrett site and found a Starrett T436.1XFL-1 that looked good.Anyone familiar with this mic?
steveno
Member
check the local pawn shops. sometimes if there is a lot of machining in the area and there are layoffs sometimes the tools are the first to go to the pawn shop for money. these machine shops usually had an inspection program to make sure that they are working properly. I got a .0001 inch Starrett for $15 at a pawn shop
OP
Milton
US Veteran
Thank you,I will do just that!
DWalt
Member
A pawn shop might be a good idea, maybe also Craigslist. I once bought a nice boxed nest of micrometers from 1" to 6" at an estate sale for I think about $30. Most of them I have never needed to use, but if I ever do, I have them. They did need some TLC to get back into working condition. For most of my needs, a dial caliper works just fine. I have a pair of Mitutoyos, 4" and 8", also I have a 20" vernier caliper, again something I have very seldom needed. It reads to 0.01". For some reason I cannot warm up to using digital measuring instruments, probably because I grew up in an analog world.
Ben_hutcherson
Member
I have a 1" Starrett "C clamp" vernier along with a Watch-Craft branded vernier bench micrometer. The Starrett will go to .0001" and the Watch-Craft goes to .01mm.
Both were used. The Starrett cost me $20 I think, while the Watch-Craft was in another lot of watchmaker's tools.
Use some care when buying a used one. The jaws should be perfectly parallel and have a mirror polish. Otherwise, you're going to introduce some error just from measuring at different places on the jaw. The screw should offer a small amount of resistance, but should be easy to turn with one finger. On the ones I have, it's possible to adjust the ratchet tension and it needs to be set correctly to get good measurements.
BTW, I was taught to click the ratchet 3 times. I at least get repeatable results by doing this.
Also, at the level of precision you're considering, a bench micrometer will really serve you better than a hand held "C" one if it's such that you can use it. Thermal expansion is a real issue, again especially at the precision you're discussing. Bench micrometer are much less susceptible to this, both because they're not being held in your hand and the fact that they have a lot more mass.
Both were used. The Starrett cost me $20 I think, while the Watch-Craft was in another lot of watchmaker's tools.
Use some care when buying a used one. The jaws should be perfectly parallel and have a mirror polish. Otherwise, you're going to introduce some error just from measuring at different places on the jaw. The screw should offer a small amount of resistance, but should be easy to turn with one finger. On the ones I have, it's possible to adjust the ratchet tension and it needs to be set correctly to get good measurements.
BTW, I was taught to click the ratchet 3 times. I at least get repeatable results by doing this.
Also, at the level of precision you're considering, a bench micrometer will really serve you better than a hand held "C" one if it's such that you can use it. Thermal expansion is a real issue, again especially at the precision you're discussing. Bench micrometer are much less susceptible to this, both because they're not being held in your hand and the fact that they have a lot more mass.
There are vernier calibers, but none that are accurate to a tenth of a thousandth. And there are micrometers that are accurate to a tenth of a thousandth, if they are calibrated. But there are no things as vernier micrometers.
As noted, Starrett makes some high quality measuring equipment. If you buy used, you can save money, but you also need to be able to check it to ensure it's still accurate and properly calibrated. Calibrating is easy if you have the tool to turn the micrometer's barrel. But calibrating doesn't mean the micrometer is accurate. If the micrometer's threads are worn or damaged, no amount of calibration will make it accurate.
As noted, Starrett makes some high quality measuring equipment. If you buy used, you can save money, but you also need to be able to check it to ensure it's still accurate and properly calibrated. Calibrating is easy if you have the tool to turn the micrometer's barrel. But calibrating doesn't mean the micrometer is accurate. If the micrometer's threads are worn or damaged, no amount of calibration will make it accurate.
Your post reminded me of a blog post by Grant Cunningham. 
"Bull-loney Tenths"
(Not the ACTUAL name of that page, but censors would've intercepted it otherwise.)
"Bull-loney Tenths"
(Not the ACTUAL name of that page, but censors would've intercepted it otherwise.)
If you want to try and measure in tenths get a set of window "mikes", either Brown and Sharp or Starrett. But as others have suggested Micrometer's were not intended to be used to measure work that close. In most cases + - .005" is close enough for most work.
I'll argue that. A vernier is the read out on any device where you have to look at where the lines align, not to be confused with dial or digital tools.
Most micrometers are is in fact a vernier device.
Protocall_Design
Member
I prefer a mike with a friction thimble. Most ratchet thimbles are more like an impact wrench. You can probably get a nice Brown & Sharpe on eBay for $30 - $50. Micrometers are definitely made to measure to a tenth. As a Tool & Die maker I've been doing it for 40+ years.
Rastoff
US Veteran
I have never personally seen one that accurate with a vernier scale. I have personally used a digital caliper that had an accuracy of +/-.00005". So, it's possible.
This is simply inaccurate. This is a vernier micrometer:
This is a digital micrometer:
This one still has a basic vernier scale though.
Um, what? No, turning the barrel is not calibrating. That's how you zero the scale.
I've been a Metrologist for 32 years. I've calibrated thousands of micrometers. New ones, old ones, expensive ones and cheap ones. There are micrometers that have a +/-.001" tolerance, but they aren't worth having. A digital caliper is much easier to use. Most micrometers are +/-.0001" and take a little skill to read. Do you need that tolerance? Yes, if you want to trust your measurement.
I would discourage you from buying a used micrometer. They are easily damaged and very few actually know how to take care of them.
The real question here is, what is expensive to you? To some $100 is inexpensive and to some it's expensive.
Starrett does make quality tools, but they are not the best. My "go to" measuring company is Mitutoyo. However, Brown & Sharpe, Fowler and Starrett do make good tools.
The next question is, what will you use this for? I have access to some measuring tools with far more resolution than you're asking for, but I use this most of the time:
The accuracy is +/-.001" which is more than most people need. Also, it's easier to read digital than a vernier scale. More, this measures inside, outside and depth. A micrometer can only measure one dimension.
I agree with you Zonker, I'm not a master machinest, but I have
spent a lot of time with the old transits ( not at the time I was
using them ) that were read off Vernier with glass. As a matter of
fact all my good measuring instrument are the old vernier type.
Various types of Mics, calipers, gauges. I do have some dial read
out types, but they are not the quality of my old Starret stuff. I
use them a lot for cases and such. Living in the Rust Belt good
tools are easy to pick up at yard sales, for reasonable prices.
The .0001 mic that I have has 10 markings below the scale on the sleeve. When two marks don't line up on the sleeve and barrel, you turn the mic slightly and see which of the ten marks on the sleeve line up with a mark on the barrel. So if the mic read .750+ and the 3rd mark lines up, the reading is .7503
CScott
Member
Good advice. Look for one that comes with a "standard" so you can check your calibration as often as you like on all your measuring tools.
I personally own a full set of inside and outside mics but 99%of the time I use my Fowler digital calipers which read to .0005".
While good tools are a lasting pleasure, I'm curious as to when you need accuracy to .0001". . . or .0005" for that matter.
C. Scott
steveno
Member
for most normal uses .001 is close enough for government work however if you work in a machine shop and depending upon the parts you are working with you will need .0001 accuracy
Ole Joe Clark
Absent Comrade
I have Starrett and Brown & Sharpe mikes from way back when, know how to zero them. Used them for precision work when I worked in the shop. They never let me down.
We can split hairs about how flat is flat, or how round, or what diameter, but in most cases since retirement +/-.001 is more than close enough. We could argue light bands though.
We can split hairs about how flat is flat, or how round, or what diameter, but in most cases since retirement +/-.001 is more than close enough. We could argue light bands though.
