Author Topic: Brown & Sharpe  (Read 165 times)

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Offline lptools

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Brown & Sharpe
« on: November 09, 2019, 04:58:03 PM »
Hello, After a little digging, I found out that these are called Standard Caliper Gages.  All are stamped with a decimal and fractional size from 7/16 to 1-1/8. All are stamped Brown & Sharpe, (the smaller ones B & S) . What I can't seem to figure out is how they are used?? Any help?? Thanks, Lou
« Last Edit: November 09, 2019, 05:56:41 PM by lptools »
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Offline leg17

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Re: Brown & Sharpe
« Reply #1 on: November 09, 2019, 07:33:37 PM »
Those are, in fact, "caliper gages".
Prior to the readily available micrometer, much measuring in the machine shop used plain calipers, inside and outside.
Much of the work involved 'fitting' one piece to another, so commonly, the more difficult piece would be made, then the other one fitted to it.  A plain caliper, say inside, would be adjusted to the first piece, then the mating piece would be measured by an outside caliper referring back to the inside caliper.
But what to do when a particular size is required?
These standard 'caliper gages' functioned as master gages, similar to modern gage blocks.
Calipers were set to these gages, rather than some mating part, and absolute size was possible.
(Keep in mind that NOTHING is absolutely perfect, but a good part is within acceptable tolerance.)
They were relatively expensive in the day.
Contrary to much foolishness on the internet today, they were NOT used as plug gages to actually measure a workpiece, but only reserved to set calipers, just as gage blocks were originally intended.
The versatility and availability of gage block sets rendered these obsolete around WWI, and today asian gage blocks are so inexpensive they are commonly not treasured as they used to be.

Offline lptools

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Re: Brown & Sharpe
« Reply #2 on: November 10, 2019, 05:05:25 AM »
Hello, leg17. Thanks for the info!! I knew they weren't plug, or "no-go gages, but I had the wrong idea that they were used like a micrometer standard. After reading your post, and re-reading my catalog description, it now makes sense. So, I now have (with your help) Standard  Caliper Gages No.669 Style 2 Internal , (I believe they are referring to the Inside of an Outside caliper). These were listed in a 1941 catalog, the smallest size for $4.60, and the largest for $5.25!!   Adjusted for inflation, that would be $93.54 for the smallest size, and the largest size would be $93.54!!! Thanks again, Lou
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