# Harbor Freight Digital Micrometer



## jgedde

I will first preface this by saying I'm generally not a huge fan of electronic digital measuring tools....  I was in Harbor Freight last night to buy a new buffing wheel.  As always, I left the store with more than I went in for.

As I was browsing I saw a digital micrometer on sale for $34.95.  My immediate thought was that must be a piece of garbage.  But I opened the box and took a look...  It appeared to be well made.  I turned it on and it zeroed consistently.  I noticed the display read to 5 decimal places  (technically 4-1/2).  Yeah right I thought.  But for that price ($27.18 with the 20% coupon I printed online), I figured what the heck.  It comes with a ball end attachment, spare battery, case, and battery replacement tool.

I got it home and started measuring things.  In every case it agreed with my mechanical 0.001 mike and seemed to measure things I more or less knew the size of to sub 0.001 accuracy and do it accurately and consistently.  I don't have jo-blocks, Deltronics or anything like that at home so I was limited in really testing this thing.

Here at work we have a mechanical inspection department with super high end stuff in a HEPA filtered, environmentally controlled room.   This morning I gave the new mike to the head inspector and he checked it against his Grade AA Jo-blocks.  In every case it read accurately and consistently to 0.0001"  Needless to say I'm shocked at how well this thing works!

Of course I don't know how well it will hold up, and I haven't yet dropped it, but so far its a big winner...    If someone asked me to think of one complaint about this instrument I would say that it doesn't have the feel of the $500 Mitu or Starrett units we have.  But this would be nitpicking - the feel of it is not bad at all.

It doesn't show up at HF's website so I can't post a link, but here a photo of the unit...




John


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## 4GSR

HF, here I come!!!!:biggrin:


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## Higher Precision

Its looks identical to the Fowler 54-850 series micrometers.  I know the Fowler ones come with a 1 year warranty, did the Harbor Freight model come with any type of warranty?  Good find.


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## jgedde

Higher Precision said:


> Its looks identical to the Fowler 54-850 series micrometers. I know the Fowler ones come with a 1 year warranty, did the Harbor Freight model come with any type of warranty? Good find.



90 days according to the manual. I know HF has an unconditional 30-day return policy also.  But, it's 1/3 the price of the Fowler at online prices.

By the way, I learned that a fingerprint has measurable thickness with this mike...  The moral?  Keep your mike anvils scrupulously clean!

John


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## jgedde

etard said:


> Is it a sacrilage to sell an old Starrett Mic for this HF? :thinking:


  Yes it is!    Keep your Starrett and get the HF.  The Starrett will be working reliably after the HF unit is dead and gone, never needs batteries, etc...

John


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## kd4gij

I picked up one of these about a mounth ago. Did the same thing as the op took it to work and checked it with the gauge blocks in the calibration department. It is just as accurite as the mikes we use. Can't beat it for the price.


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## ScrapMetal

Damn it, damn it, damn it!  I hate you guys!  Now I've got to go look at one.   I don't really need it but at that price/performance it would be hard not to get one for backup if nothing else. 

I'll even take in one of their 20 percent off coupons and get it even cheaper.  Damn it! :biggrin:

-Ron


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## arvidj

The part number is 68305 if you want to call ahead to see if they have one on hand. I am still stunned by getting 20% off AND a free multimeter


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## jocat54

It is on there web site http://www.harborfreight.com/digital-micrometer-68305.html


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## 4GSR

Bought my HF Digital mike today.

Checked it with my Mitutoyo grade 2 gage blocks.  Right on with every randon gage block .050" to 1.000", even .1001" thru .1009"!!!

Found my Starrett 1.000" round standard out by .00025"!!!

I am impressed!!!


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## jfcayron

I got one this week. It agrees with all my other references.
Happy!


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## bcall2043

*Going cold turkey is difficult*

*From another thread late Saturday 4/28/12* 


bcall2043 said:


> 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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## Charley Davidson

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.


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## Tony Wells

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'


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## Charley Davidson

42 said:


> 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:


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## OlCatBob

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


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## Tony Wells

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.


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## bcall2043

42 said:


> 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


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## Tony Wells

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.


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## bcall2043

42 said:


> 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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## Charley Davidson

bcall2043 said:


> 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



Benny, check again, they do go to 5 decimal points.  Now you have to edit your edit and retract your retraction:lmao:


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## Charley Davidson

Gordon Clarke said:


> To avoid confusing me how about going metric and there should be 3 digits after the decimal point if it is the accurate micrometer I think it is
> 
> It should read in 0.001mm. or 1µm (which is the same).



It does

3 digits past the . in metric  5 in inches  have it in my hand right now


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## jgedde

42 said:


> 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 the right n mber was 0.0001 not 0.00001.  The latter has to be a mistype.  The HF mic only reads (resolves) to 0.00005...  In other words, 4 1/2 digits.  For 10 millionths I agree with your statements on temperature, but not for 0.0001 unless the temps are dramatically different then what the instruments were calibrated at.

John


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## jgedde

Charley Davidson said:


> 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.



He clearly meant 0.0001.  The mic doesn't read to 0.00001...

John


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## Tony Wells

Per the manual for the instrument:

7. This Micrometer measures items in hundred thousandths of an Inch.

That statement should be taken to mean "able to read in 10 millionths increments", not the typical half-tenths (50 millionths) you get with a 4 1/2 digit readout. Of course, it may well be that the instrument is truly a 4 1/2 digit display. I would guess that it is just that. Otherwise, my concern about accuracy stands. 

John, I would tend to agree that under normal ambient conditions, a micrometer and a standard or gage block would need to be several degrees apart to cause any issues in the +/- 0.0001 range. The materials of choice for those items are chosen partially for their temperature stability over the normal range seen during use. The CoE is quite similar. I was only giving the guys something to think about, perhaps for next time and for their edification.


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## Tony Wells

Gordon Clarke said:


> 42 i hope you don't take this as too personal or negative but you remind me of those that taught metrology back when I knew a lot less than I do now. You manage to express and turn what are in fact non complicated issues into a paper fit for a master's degree.
> 
> This is after all a forum for those working with machines and checking/measuring what they make from a hobbyist's perspective. From what I read the vast majority are both knowlegable at what they do and have the common sense to do what is right.



Well, it is a remark of a personal nature, isn't it? However, I am not insulted or bothered in the least by it. It is simply my style to strive for technical accuracy when I write something on the Internet (or elsewhere) that may be read by those perhaps less informed or experienced than I. I am also aware that the majority of the members here are knowledgeable, and yet at the same time, many are beginners. 

And the drivel I write here most certainly would not pass for a Masters thesis, but thanks anyway.



Gordon Clarke said:


> A suggestion. Why not start a thread with the title "the theoretical side of Metrology". It would prove interesting (at least to me) as there are a couple of things you have written that I don't agree with. The only reason I haven't stated what they are in a current thread is so as not to off track the thread/theards in question completely.



I will not do a thread on this forum that addresses the Theoretical Metrology for the same reason you stated as the reason I shouldn't write the way I do: This is a Hobby Machinist Forum. I'm sure it would bore most of the members anyway, and fail to be pertinent to their machining activities.



Gordon Clarke said:


> It almost certanly isn't your intention but I feel that I'm being spoken down to when I read much of what you write.
> 
> Gordon



Gordon, that is absolutely the last thing I want to do, or even give the impression of doing to you or anyone else. I have respect for my fellow man. Especially so for those who would take up machining for a pastime. Most people who do it for a living too, for that matter. There is so much talent on this forum, and many others, that I that look up to my fellow members, never down. I sincerely apologize if you feel slighted or insulted. It is not intended at all.



Gordon Clarke said:


> Re your first sentence - does the micrometer really come with a manual? Stating what you write after 7. then I can only say that any manual having something like that in it would be a first for me.



It may not come with a printed manual, but the website HF markets the instrument on has a download of it, and I was merely quoting from it. I did not feel it necessary to paste in the entire section I quoted. Like so many things though, I have my doubts about the veracity of the statement.


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## Tony Wells

Not to worry, Gordon old bean.....I did not take it _too_ personally!


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## AR1911

I got one of these for Father's Day.  Sat down and fiddled with it last night. 
Mine will not change to inches, it's stuck on metric.  
So I'll be exchanging it pretty soon.


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## Video_man

AR1911 said:


> I got one of these for Father's Day. Sat down and fiddled with it last night.
> Mine will not change to inches, it's stuck on metric.
> So I'll be exchanging it pretty soon.



Mine requires holding the inch/metric button for about 5 seconds before it makes the change, which is probably a feature and not a defect.  Same for the zero setting.  On/off = quick push, zero = long push, abs/inc=short push, inch/metric = long push....hope it's working for you, I really like this mike...


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## AR1911

That was probably the only combination I did not try.
thanks for the tip


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## Charley Davidson

AR1911 said:


> I got one of these for Father's Day.  Sat down and fiddled with it last night.
> Mine will not change to inches, it's stuck on metric.
> So I'll be exchanging it pretty soon.



I thought the same thing as I was trying it out in the store but discovered it's little seceret so bought me one. Paul also gave me one of those in the care package he sent home with me so I let my friend have it to go along with his lathe.


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## fastback

Well I started reading this thread and was impressed at what was being said about the HF digital.  So impressed, I went to HF (about 2 miles from my house) and bought the only one they had on the shelf.  Naturally, once I got it home I needed to try it out.  It didn't work on the inch scale.  When I pressed the mm/in button I was able to get MM and a reading.  I don't use metric so I switched to in.  Now inches did show on the readout (actually both in and mm showed at the same time) however, it only read in metric.  So needless to say I brought it back, but they had no others in stock.  I decided that I had to buy something so I bought the no battery digital.  Now that one worked just fine.  Oh, and I got a free 25 foot tape measure to add to the other 20)

I don't want you to think that this will be my only mike I have a number of them.  I have multiples of 1, 2, 3's as well as a Starrett 2 to 6 inch.  You need to change the anvils.  I bought a new one so when my eyes are tired I can still read without a magnifying glass.  I now have 2 Starrett 436, a Brown & Shop w/ no ratchet.  This one is my favorite.  I also have a Craftsman I got when I started trade school (was there only a short time before transferring to regular HS) a set of 1, 2 and 3 made in china that was given to me.  I guess at some point I'll try another digital when HF gets new stock


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## Analias

I bought this tonight when I went in to pick up the machinist style tool boxes HF has on sale for $69 (member price).  No discount, but the temptation became great enough that I put them in the basket for $34.95. 

When I got home I pulled out my gauge blocks and gave them a quick test.  If you look at the inspection sheet for the gauge blocks you'll see that the .100" block has +2 on it.  I zeroed the mic and gave it three measurements:  .1001, .1002, .1001.  Not bad.








Hopefully, I have attached these correctly.


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## fastback

Hope it continues to work out well for you.  One question, why didn't you use a 20% of coupon? The price you paid is a good price, but you could have gotten another $7.00 off.   I was just wondering.  I never buy anything at HF without a coupon.


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## rebush

Tony: Always enjoy reading your posts, and have always learned from them. I don't believe there's such a thing as too much good information. Roger


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## Kroll

http://www.rockler.com/product.cfm?page=25446&site=ROCKLER
Just another option---kroll


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## Tony Wells

rebush said:


> Tony: Always enjoy reading your posts, and have always learned from them. I don't believe there's such a thing as too much good information. Roger





Thanks, rebush. I've been accused of providing too much information, but I'd rather give too much than not enough. Glad you enjoy reading!


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## MikeWi

fastback said:


> I don't use metric so I switched to in.  Now inches did show on the readout (actually both in and mm showed at the same time) however, it only read in metric.  So needless to say I brought it back, but they had no others in stock.



I was confused about this as well (bought this yesterday) but it takes a very long press on the mm/in button to get it to switch to inches.  the inc mm you saw meant that it was in incremental mode for mm.  It was actually working fine!


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## GK1918

Cant say that I dont get up early, my son dragged me off I figure nothing to lose for that price,  NOT a
single mic on the shelf.  Oh well.  > up to 7 inch snap gauge set, 20 piece end mill set  HSS tool blanks,
box of HSS parting,  and some other junk.  I call all of this my backup stuff.  Gotta good chuckle out of
the end mill wood box.  Ole Tubal nailed that one, a barefoot kid, dirt floor shop you just gotta see 
the hinges or an extremely rough ride on the boat.  My cat could do a better job.  This is hard to explain
one hinge close to correct and the other 90 degrees to the correct one and the worthless screws split
the wood.  For fun I glued and clamped the box, put a brass piano hinge a little mahog. stain so it now
resembles a box.   To think about it no one could be that stupid,  more like a joke or mad at the boss.
I wont say what my kid spent, he needs theropy !


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## Ray C

I just picked-up this same mic yesterday.  I took a chance on one that  had a damaged box and was marked down at the sidewalk sale for 25 bucks.   The mic was fine but the plastic box -not so good.  It got stepped on  or crushed.  I asked if I could return it if discovered it was way out  of calibration.  The Mgr yes yes.  I have a 1" standard and a only a  couple gauge blocks and it checked-out fine.

-And yes, it took a bit of fiddling to get the in/mm and zero function  figured-out.  Mine did not come with an instruction sheet so I had to  fiddle w/it.  You know, I think I like that thing!  My eyes are really  struggling to see regular mics anymore.  



PS:  Note to MikeWi.  I accidentally started to edit your original post.  I meant to reply to it but pressed the wrong button.  I did not change any of your content or statements.  Please accept my apology.  I simply pressed the wrong button.



MikeWi said:


> I was confused about this as well (bought this yesterday) but it takes a very long press on the mm/in button to get it to switch to inches.  the inc mm you saw meant that it was in incremental mode for mm.  It was actually working fine!


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## Ray C

BTW:  I hope you guys are aware this thing comes with a ball anvil inside the box.  Handy for reading irregular diameter stuff.  With the ABS and INC function, it can be used w/o doing any subtraction.  See the pic.

Ray


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## Analias

Oh, is that what that is? I thought it was some kind of gauge block for calibrating the mic. I figured I was wrong since the value of the gauge was so weird.

Sent from my Nexus S using Tapatalk 2


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## fastback

Mike, thanks for the info.  I thought that I had held the button down for a long enough period, but maybe not.  In Fact, I was not alone at the time, a friend also tried to reset it but nothing seemed to work.  I may give it another try, but this time I will try it out in the store.  What's one more micrometer.

Yes Ray, it did come with the ball add on I had to pay extra for the one on my Starrett.


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