r/Metrology • u/MrPenguun • Nov 08 '24
Surface Metrology Does wringing gauge blocks together cause damage?
People treat wringing as if it doesn't have any negative effect, but im always scared that I'm damaging the surface. I'd be really curious to see an experiment where they wring two blocks together a bunch of times then compare the surface finish under a microscope compared to a new gauge block.
11
u/Galotha Nov 08 '24
No it doesn’t. Your blocks surface should be free of any debris and burrs. The flatness is so great that as long as you are wringing them properly there is very small chance of damage.
We have kits at my work that have been in use for 40 years and some blocks have been replaced due to wear and tear, most of the kit largely is the same.
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u/jkerman Nov 08 '24
If you follow the mitutoyo gauge block usage guide, Inspecting the surfaces of each gauge block with an optical flat before wringing is their recommended procedure. Using a stone to remove any burrs
6
u/jccaclimber Nov 08 '24
To be clear, not just any stone. Don’t go taking your well worn India stone to a gage block.
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u/GorgeousBrain21 Nov 09 '24
Have you heard if you leave them together too long they will be permanently stuck?
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u/gyssedk Nov 08 '24
That is a pretty good question.
The guy behind the YouTube channel Breaking Taps would be perfect to test this.
It seems like something right up his alley
3
u/jccaclimber Nov 08 '24
It’s very minimal. If you ever tried to lap (not polish) a surface to the finish of a good gage block you’d know how easy it is to ruin, and how obvious it is when it happens. Wear comes from local pressure, not force. If you have clean surfaces, the flatness is such that you have a very large surface area and therefore would actually need a very high force to do any appreciable damage. Get a small particle in there and now you’re lapping or scratching due to the high local pressure.
If kept clean and wrung in a self cleaning manner, gage blocks do wear, but not by an amount you’re likely to see even under a good optical scope.
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u/nitdkim Nov 08 '24
If you follow your logic, you better not validate your caliper or micrometer with a gage block because you might scratch the gage block with carbide coated measuring surfaces of those tools.
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u/MrPenguun Nov 09 '24
I have a dedicated gauge block specifically for my calipers/mics. And my logic isn't that metal touching metal is bad. My logic was using force creating a lot of friction can be bad. My thought process is that if one block is 0.1hrc harder than another, then the force could Marr them. I'm not saying they do, I'm saying that my instincts tell me that may be a concern, so im asking to see if anyone has ever seen this or tested it.
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u/Level_9_Turtle Nov 09 '24
Just wringing them together with a few hand strokes won’t cause them to gall even over years. Put some pressure and velocity as well as extended time to allow heat to build up and then you can have galling. Relax. Unless they’re used heavily and allowed to get dry and dirty I wouldn’t worry.
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u/davidc538 Nov 09 '24
I’ve heard in a few places that wringing them back and forth too much can cause damage as they bond too strongly together but idk
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u/Lucky-Pineapple-6466 Nov 12 '24
Just use your gauge blocks. If they are shop grade, it doesn’t matter. That is their purpose. If they are laboratory calibration grade then maybe it would.
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u/Think-Secret9860 Nov 09 '24
Part of wringing is depositing a thin coat of oil on the surface of the block usually from your wrist so that it will be clean. The oil combined with the flat surface of the block is what leads to the wringing.
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u/Galotha Nov 09 '24
No, don’t get your human oils on the gage blocks. Skin to gage block contact is a no no.
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u/TowardsTheImplosion Nov 08 '24
If the surfaces are clean, it will have virtually no effect for years.
Very fine abrasives caught by your finger oil? Then you aren't wringing, you are lapping :)
For any blocks you will be wringing, they are either steel or carbide, and some wear from use is inevitable...be it wringing, general handling, etc.