Thread: But we did agree to disagree

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HotRodPaint:I am like you I spent many years working in the Tool & Die Industry.Normally when you saw a two place decimal (.02) you could hold that tolerance easy,usually + or - .010.When you saw a three place(.002) decimal it was usually + or - .005 which required a little thought.When you saw a four place decimal (.0002) it was usually + or -.0001 and you were usually grinding to hold that tolerance in a controlled environment with calibrated measuring instruments. I know greater tolerances are attainable but they never came my way.

I'm in Tool & Die, I build Investment Molds, and specialized in airfoils, Turbines & turbo's. We have lost most of our tolerance yrs ago, we have to be with in .005 in one place (.1), with in .001 on two place (.12), with in .0005 on three place (.123), and with in .0003 on four place (.1234) @ 72 degs.
Years ago on a .1 Number, using a scale was almost close enough, and a dial Veneer (dial very-near) was used on .001 (I have always used a micrometer) Give 10 people a veneer and you'll have 10 different numbers.

Pat

[Give 10 people a veneer and you'll have 10 different numbers.


My experience has been, give ten people a verneer caliper and they will make a career out of trying to figure out the dimension, never get it right and say that is allowable tolerance. I do know an elderly gentleman who can read a verneer as accuratly as a mic. Says his first lathe was ran by a foot treadle till he got a steam engine to run it.