We are seeing surface finish symbols with only an "S" under the surface finish symbol, what does this indicate?
I have never seen this before (see sample sketch below)
That position within the surface roughness symbol is used to indicate the lay or direction of the tool marks produced by manufacturing.
There is not an "S" designation within ANSI B46.1. I suspect that they meant "C" for circular tool marks or lay as opposed to "S".
I would ask the engineering drawing creator/owner for clarification.
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