Harbor Freight Digital Micrometer

I got one this week. It agrees with all my other references.
Happy!
 
Going cold turkey is difficult

From another thread late Saturday 4/28/12
I have started the twelve step program for tool addicts and now have one day in a row without a single tool purchase.

Benny
Recovering tool addict and incurable Hobby-Machinist

Well it happened, Charley called last night and said he was going by HF this morning to look at the digital micometers reviewed in this thread. I declined the offer to go along as I had plans with the wife and I did not need another 0-1 micrometer. This morning the wife did not feel like doing what we had planned so I called Charley and off we went to HF. I took along one each of 0.126, 0.250, 0.500, and a 1.000 inch gage blocks. We set down in the middle of the store floor and took the digital micometers out of the box and checked them with the standards. Had to clean the anvils to get good zero and then all the readings were right on. We both now own a new digital micrometer and back to the start of the recovery program for me. Is this Charley's fault or is there just no hope for me?

Benny
Once an addict always an addict

Edit - 0.250 was 0.0250
 
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Quite impressive for the money, I think Benny's checked out dead nuts & mine was dead nuts to .00001 :thumbzup:

I had decided to pass on this deal last night after Benny said he didn't think he was gonna go along, But at 8:AM sharp my phone rings and it's Benny saying he want's to go get one of these so I reluctantly agreed to go along and do a sympathy buy to keep him from feeling all alone in this. Tomorrows a new day.
 
To be fair, speaking in Metrological terms, a gage block and the DUT should be allowed to come to the same temperature (68° @ 50% RH, or 20° C) for 24 hours in order to really quantify measurement or calibration error. As an extreme example, if your block or standard was in your pocket, and the instrument was off the shelf temperature in the store, your readings really shouldn't show a zero error if the instrument is correct. The warmer block or standard is really larger than stated. If the instrument says it is right on size with the temperature differential, the instrument is less than accurate.

Jus sayin'
 
To be fair, speaking in Metrological terms, a gage block and the DUT should be allowed to come to the same temperature (68° @ 50% RH, or 20° C) for 24 hours in order to really quantify measurement or calibration error. As an extreme example, if your block or standard was in your pocket, and the instrument was off the shelf temperature in the store, your readings really shouldn't show a zero error if the instrument is correct. The warmer block or standard is really larger than stated. If the instrument says it is right on size with the temperature differential, the instrument is less than accurate.

Jus sayin'

We called ahead and had them pit the mics in a climate controlled room and Benny put the gauge blocks in a brief case that he bought from a James Bond movie that is also climate controlled. We then entered a vacuum sealed chamber and checked the mics under strict NASA requirements that were in a sealed titanium canister certified to be accurately fitted for this document. We are certain these will meet our strict calibration requirements for the rocket science & brain surgery we both plan to practice.

I mean Really?:headscratch:
 
Charley, Charley, Charley... Ya gotta keep those things in a hermetically sealed mayonaise jar under he front porch, Geez! I thought everybody knew that. :)

Bob
 
Guys, all I am saying is that if you are thinking that you have an instrument good to the 10 millionths of an inch, it's not likely. You do have to go through some serious hoops to qualify an instrument to that level of confidence. For hobby purposes, and indeed most industrial/commercial applications, that micrometer is certainly capable of satisfying the needs you have.

No insult intended.
 
To be fair, speaking in Metrological terms, a gage block and the DUT should be allowed to come to the same temperature (68° @ 50% RH, or 20° C) for 24 hours in order to really quantify measurement or calibration error. As an extreme example, if your block or standard was in your pocket, and the instrument was off the shelf temperature in the store, your readings really shouldn't show a zero error if the instrument is correct. The warmer block or standard is really larger than stated. If the instrument says it is right on size with the temperature differential, the instrument is less than accurate.

Jus sayin'

Thanks for the training we are here to learn. Your point about the difference of temperature between the micrometer and item being measured is a good one. To be real we are Hobby-Machist and will almost never work under perfect conditions. My shop has no heat or air conditioning and I rarely wait for a part to cool down after a heavy cut before measuring it. But then I rarely take heavy cuts. The point is that we checked the tools in the store (under less than perfect standard conditions) and both micrometers read almost the same measuring the several different standards between 0 and 1 inch for repeated measurements. In the hobby shop barring damage or dead batteries the tools should serve us well at a value cost and we don't have to read and count all those little lines.

Now you got me concerned that Charley and I bought two bad micromenters with the same manufacturing errors and our test methods did not catch it. :lmao:

Benny
 
Very likely both those micrometers are far more than adequately accurate for anything that might come along. If all you guys saw was a 0.00001 difference, that's outstanding and nothing to worry about. Plus point is well taken about reading the basic markings, much less the vernier scale. I'm all with you on that.
 
Very likely both those micrometers are far more than adequately accurate for anything that might come along. If all you guys saw was a 0.00001 difference, that's outstanding and nothing to worry about. Plus point is well taken about reading the basic markings, much less the vernier scale. I'm all with you on that.

I think we are talking about different numbers. The micrometers we bought measure only to 4 decimal points not five but probably still okay for what we plan to do.

I went back and looked at the earlier posts that Charley and I made and Charley got the decimal pont in the wrong place in his number and I have a error in the second standard I listed. That standard should be 0.250 not 0.0250. I will edit my post to correct my error if system allows. Charley's number should be 0.0001 not .00001, don't think I can change his.


Sorry for the confusion.
Benny
 
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