Comparing Gage Block Sets

I would not trust any inspection sheet from China. All the ones I’ve ever seen are a xerox copy with a scribble. This is why a starrett or mitutoyo sets cost so much. All the sets I have are auction buys do-all, mitutoyo, and starrett. Inspections on three sets were in the late 80’s but I don’t care because I will NEVER be making stuff that requires that kind of accuracy. I maybe paid 50 bucks a set all the blocks ring even from different sets.
I can’t see any hobbiest or a large percent of professional machine shops being able to measure to that tolerance let alone machine to that tolerance. Jmo
 
Lucas I understand your desire for very accurate gauge blocs set, and if you can afford the best, then why not? However as your OP implies being on a budget makes one open to cheaper alternatives... I bought an offshore uncertified set about 35 years ago. I have measured it in a lab against their best set using a half tenths indicator that could be read to about a third of that. Only one block had any discernible deviation.

What I'm saying is that you get a lot for your money no matter what set you buy.

Now tracking requirement for precision: are you machining to one thou precision, half thou or better? My own personal opinion machining for 40+ years, and having firends in the trade much longer is this:

Develop skills and techniques like lapping, turning, finsihing and honing. Use the best measuring tools you can afford. With 25+ years experience, you will be able to reliably machine and finish to sub-thou. Many home machinists fool themselves into thinking they can do better.

Even on the best surface grinders, for instance, it takes years to become a grinder hand and grind to 2 tenths overall and square. The best a beginner can hope for is around 5 tenths on a new, tight machine, properly dressed wheel proper hardness and grit with perfect cooling.

The Shars sale one will do you for many years. If you develop the skills to even measure to better tolerances, you will have hundreds of thousands of dollars invested, and buying a better set will be a drop in the bucket.

This is one time 'buy cry once' doesn't work. Buy a Shars set and use, abuse and wear it until you have the habits to care for a good set. The cheap set becomes your setup and shop set, and your good set is used only for specific operations. All really good tool and die shope used to follow this principle.

My mentor had the skills to machine, heat treat, and grind inserts for punch presses. He could stack 20 of them in a stack and measure the the whole tolerance was less than 2 tenths. it took him 10 years to get it that good, with 20 years already under his belt. This is the advice he gave me when I bought my first set.
 
^^^ is excellent advice!
 
I have a 20" gage block. Its a Webber block, made by LSS. Co. It was scrapped by the U S Government (really) in the 1970's. In the 1990's the company I worked for purchased measuring instruments that would allow me to check out my 20" gage block. At that time it's length was 20.0008.
Apparently steel is not stable. I use gage blocks in set up, but don't rely on them for 100% accuracy.
 
I bought the Shars metric as well as Imperial gage block sets. I was disappointed with the accuracy and consistency of both sets. I have a lot of Shars metrology products, and I generally find these to be a waste of money.

Shars is good for some purposes, but accuracy and consistency are not among them. If you were buying metrology products for a school or occasional casual use, Shars is a good choice. Shars products look good in photos, are very affordable, and they have very fast shipping. Their analog 0-1” screw thread micrometer has never let me down.
 
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Hey @erikmannie, I generally like Shars for a lot of things as well, but I don't have any of their metrology stuff. I've got mostly vintage Starrett and Mitutoyo.

Care to elaborate on the accuracy issues with the gage blocks?

How far off were they from the stated tolerance?

And how did you measure?
 
JRaut said:
Hey @erikmannie, I generally like Shars for a lot of things as well, but I don't have any of their metrology stuff. I've got mostly vintage Starrett and Mitutoyo.

Care to elaborate on the accuracy issues with the gage blocks?

How far off were they from the stated tolerance?

And how did you measure?
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When I first received the gage block sets, I only had Shars digital electronic mics and no mic stand. This went off the rails immediately as far as checking the gage blocks against the mics and vice versa.

Now I have Starrett mics and a mic stand. I have a week off now, so I will take a look at this right now using the Starrett mics and mic stand.

All of the coin batteries died in my Shars digital electronic micrometers, and when I put in new batteries all of them will now only read in mm.

Let me know what process you want me to undertake. In the meantime, I will check some random ones right now and post the results.
 
T Bredehoft said:
If you strive for perfection you will be dissatisfied with everything you do and will soon look for other avenues to perfection. Good luck.
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Interesting (off the subject)
I'm working on my replacement. He is a perfectionist, an outstanding guy and he expects perfection from people.
I told him he is going to be disappointed. You can't expect perfection from imperfect people.
You try to bring out the best in those you have.
Sorry,
It was just an interesting comment as we were just discussing this.
 
erikmannie said:
I bought the Shars metric as well as Imperial gage block sets. I was disappointed with the accuracy and consistency of both sets.
Click to expand...

You say that you're disappointed with the accuracy and consistency of the gage block sets.

Just curious what you meant by that. How inaccurate are they? And how do you know?

I don't have a metric set, but would like one. So I'm shopping around.
 
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