Check blocks for digital calibers

[RussellC]

Recommendations for checks, that are accurate and affordable? I swear when I first got my Mitutoyo digital calipers they were reading the same as my HF cheapie did. The other day I was measuring some rounds that I had set to 2.250 with the HF calipers. I remeasured out of curiosity with the Mitutoyo set and was getting 2.248. I feel certain they are more reliable than the HF set, but thought it may be a good idea to check. Suggestions? I see all sorts of them for all sorts of prices on Amazon and elsewhere...

Russellc

 

[glc24]

I would definitely think the Mitutoyo to be more accurate than the cheaper HF. A set of feeler gauges could suffice as "checkers". Also a coin could be used. I'm thinking the newer the coin the better though.
https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications

 

[Rule3]

I would not be concerned with .002 one way or the other. It is pretty insignificant for most loading/shooting. Unless of course you are making big money and winning competitions. If so there are a hundred other variables to deal with.

I believe there is a thread Myth busting on the cheap vs expensive calipers. Heck how hard you close them or look at them can vary by .001.

 

[Blue68f100]

There are several way to check them. Your finding is what I found out years ago with my HF set. I found out using a set of pin gauges. I also have a set of gauges for some larger micrometers 0-4" range. The thing that I discovered was the HF was accurate on major markings. It when you get into the x.x25" -x.x75" is where there error's show up. A set of calibration gauges will run ~$100 up. It would be easier to have some one measure some things with a good micrometer and have you check against what they got.

 

[LiveLife]

A set of feeler gauges could suffice as "checkers". Also a coin could be used. I'm thinking the newer the coin the better though.

No.

I used to think verifying accuracy of my calipers with feeler gauges was good enough until Walkalong and other members posted that I need to verify my calipers in the range I was measuring. It's comparable to using check weights in the 4-5 gr range when powder charges used are 4-5 gr.

I ordered my Class ZZ plus/minus pin gages from Zoro in .355", .400" and .451" for around $3 - $5 to verify different jacketed and plated bullet diameters - https://www.thehighroad.org/index.p...re-sized-the-same.818806/page-2#post-10534024


Vermont Gage .355 plus Class ZZ Pin Gage Black Guard (Part Number 911135500) - https://www.zoro.com/vermont-gage-plug-gage-plus-0355-in-black-911135500/i/G0171595/?q=911135500

Vermont Gage .400 minus Class ZZ Pin Gage Black Guard (Part Number 911240000) - https://www.zoro.com/vermont-gage-plug-gage-minus-0400-in-black-911240000/i/G0688600/?q=911240000

Vermont Gage .451 minus Class ZZ Pin Gage Black Guard (Part Number 911245100) - https://www.zoro.com/vermont-gage-pin-gage-minus-0451-in-black-911245100/i/G3510577/

 

[rfwobbly]

I'm an expert in small pieces of information that will never make me a dime.

Here's one of them.... Digital calipers work by reading a magnetic strip that passes under the jaw of the caliper. Just like a VHS or cassette tape, that magnetic tape can be erased by coming too close to a strong magnetic field. While you may want a magnet around to search out steel cases, it's best not to leave them near the areas where you use your caliper(s).

 

[LiveLife]

Dang! You know, it's amazing what you learn on THR forum.

Thanks for the info!

 

[Walkalong]

Standards for checking micrometers etc are expensive, more expensive with a certificate.

Gauge blocks are not as expensive, but they are cheaper. The rating/price determines how tight they keep the number.

Pin Gauges are either +.0000/-.0002, or +.0002/-.0000. Not sure how tight they keep them, but the cheaper sets are not as good as the pricier ones. Vermont Gage being very good (IMHO), but not great.

It kind of depends on just how accurate you want/need to be. Rounding off to the nearest .0005 with a caliper? Well, that's not all that accurate as far as accuracy goes, but better than we absolutely need for much of reloading. I do use a micrometer capable of measuring to the nearest .0001 sometimes, but not often. Turning necks for .001 clearance (.0005 all around) in a tight necked chamber? Yep, gonna break out the micrometer, and a good one. Measuring bullet diameter? Gonna use the caliper that rounds off to .0005 most of the time.

Ever hear of "tolerance stacking"? Goes for measurements as well.

 

[Walkalong]

Dang! You know, it's amazing what you learn on THR forum.

Thanks for the info!

Same here. Always wondered.

 

[LiveLife]

Pin Gauges are either +.0000/-.0002, or +.0002/-.0000 ... Vermont Gage being very good (IMHO), but not great.

It kind of depends on just how accurate you want/need to be. Rounding off to the nearest .0005 with a caliper? Well, that's not all that accurate as far as accuracy goes, but better than we absolutely need for much of reloading

I hear you.

When we did the "myth busting" for digital scales and found that we could weigh with .02 gr resolution, I got all excited but realized with so many other reloading variables, .1 gr resolution was more than good enough for my everyday/range practice loads and even for my match grade loads with the reminder that 1000 yard matches were won and records set with .1 gr resolution beam scales for decades.

I considered getting a micrometer with gage blocks but also realized when my finished pistol/PCC load OAL varied by .002"-.003"+, being able to measure to .001" was also good enough for my loads. Now if I shot 1000 yard Palma match, I may say something different but I think using Class ZZ pin gages is much better than using coins.

 

[Walkalong]

I think using Class ZZ pin gages is much better than using coins.

By a long shot.

 

[RussellC]

Thanks, its no big deal, but I went to the expense to get a good set. The HF worked fine, I know its not a big difference, but I wondered. Looking at check blocks, some were more expensive than the calipers! Oh well!

Russellc

 

[RussellC]

I'm an expert in small pieces of information that will never make me a dime.

Here's one of them.... Digital calipers work by reading a magnetic strip that passes under the jaw of the caliper. Just like a VHS or cassette tape, that magnetic tape can be erased by coming too close to a strong magnetic field. While you may want a magnet around to search out steel cases, it's best not to leave them near the areas where you use your caliper(s).

Have no magnets, so that shouldnt be an issue.

Russellc

 

[Doublehelix]

I have a set of certified check blocks, but then again, I also have a certified set of check weights for my scale (not the cheap Lyman set).

 

[rfwobbly]

Have no magnets, so that shouldn't be an issue.

Then you may be missing out !!

Magnets are the BEST way to keep press tools close to your press. Just stick one of those super strong rectangular magnets (Lowes or Home Depot) onto your Dillon Strong Mount or Inline Fab UltraMount and it will hold all your Allen wrenches at the most convenient angle right where you can grab them quickly.

Try it once and you'll be back in the store the next day for more.

 

[RussellC]

Have no need. But, to each their own. My allen wrenches stay in their plastic holder, easy to grab the whole thing to take out shooting.

Russellc

 

[Jesse Heywood]

My only magnet in the reloading chamber is one of those on the end of a metal stick. The steel cases fly up to it. And I could use it to turn off my pacemaker, which would bring me to a screeching halt. So I won't use it to pick up my digital calipers.

 

[MutinousDoug]

If you're looking for something you may have around the house, twist drills are pretty close to nominal size if they've not been buggered up from use/abuse.

 

[Slamfire]

Follow the links provided by Walkalong. As you can see, you can buy a new gauge block set for $89.00 delivered. A couple of years ago I bought a like new Starett set off ebay for less than $100.00 New the set would have run around $1000. Probably an estate sale item.

Unless you calibrate your equipment against a known standard, you don't know what you are measuring. Posters are all the time making conclusions on their ammunition with their out of calibration measuring devices, such as bullet diameter, and they don't realize the problem is their old caliper.

For those who worked in a professional manufacturing environment, all measuring equipment will have a calibration lab label indicating when it was checked, and when it needs to be re verified.

 

[RussellC]

Follow the links provided by Walkalong. As you can see, you can buy a new gauge block set for $89.00 delivered. A couple of years ago I bought a like new Starett set off ebay for less than $100.00 New the set would have run around $1000. Probably an estate sale item.

Unless you calibrate your equipment against a known standard, you don't know what you are measuring. Posters are all the time making conclusions on their ammunition with their out of calibration measuring devices, such as bullet diameter, and they don't realize the problem is their old caliper.

For those who worked in a professional manufacturing environment, all measuring equipment will have a calibration lab label indicating when it was checked, and when it needs to be re verified.

Precisely why I framed the question. I figured with my better gauge having documentation and being new, odds are it is the most accurate. I will check for when it should be "verified."

Those pin gauges are likely close enough for me, and are affordable as well.

Russellc

 

[LiveLife]

Unless you calibrate your equipment against a known standard, you don't know what you are measuring. Posters are all the time making conclusions on their ammunition with their out of calibration measuring devices, such as bullet diameter, and they don't realize the problem is their old caliper.

Totally agree. I retired my old MidwayUSA dial calipers after buying Harbor Freight digital and Frankford Arsenal dial calipers. Consistency and accuracy of measurement readings was light day and night when measuring bullet diameters, especially when checked against pin gauges.

Those pin gauges are likely close enough for me, and are affordable as well.

Yes. Many may not want to spend the money for nicer ASTM Class 6 stainless steel check weight sets but using cheaper aluminum "reloaders" check weight sets is still way better to verify the accuracy of your scales if you are using near max or max load data.

While many may want to endorse the use of gauge blocks that cost hundreds of dollars, using pin gauges that cost a few dollars is still way better to verify the accuracy of your calipers.