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Standards of Punchings Sizes

  • 1.  Standards of Punchings Sizes

    Posted 02-04-2019 00:28

    I bought paper punchings (I believe from pianotek) and the sizes are 3 5 7 10 12 15 20 25 30 45 50 and 60mil (and the balance punchings go up to 45).  What is the origin or how did these thicknesses become standard?  Wouldn't it be just as reasonable to have punchings sizes 1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 etc. or something with easier numbering rather than peculiar numbers?  That way 2 or 3 punchings maximum would ever be needed...

    Also, the punchings that I received vary widely in accuracy.  Are there other punchings available that are more consistent?


    Cobrun Sells

  • 2.  RE: Standards of Punchings Sizes

    Posted 02-04-2019 23:50
    Cobrun, PianoTek also has .001 and .002., most every supplier goes at least to .002. If you add the .002 to your stock you can cover the missing increments by combining sizes, you can be just as precise with half the number of sizes, there are only so many colors ; ). Generally, if you're starting from scratch, you can get pretty close by doing a few tests and then going ahead and building up all the notes without measuring, then go through the cycle again and refine it using 2 or 3 of the small sizes. Then there's pounding in etc. etc. and on and on. There's an advantage in using more than 2 or 3 punchings because you have more options when you do the follow up adjustments after compression of new felts.
    The "cycle of refinement" sounds so poetic but man, it can be tedious.

    Steven Rosenthal
    Honolulu HI