【转帖】how to know the difference between symmetrical deviation
 

how to know the difference between symmetrical & deviation
how to know the difference between symmetrical & deviation
please help me............. actually i am confused between these two types of tolerance display method.
the difference is clear when lower limits have different value than upper limit. but when both are same i.e. upper +4, lower -4... then it can be symmetrical also as +- 4 and deviation also. i have attached two drawings. the dim variables are same too for both the dimensions...
can u tell me please.. how to get the difference when all dim variables are same (dimtol 1, dimlim 0, dimtp == dimtm) please look at the drawing.. and help me..
thanks alot..

can anybody help me.............................. please
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is there any body who knows about it... please tell me..
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in case of deviation tolerance display dimtp is not equal to dimtl.
on is 4.
and another is 4.000000004
i.e. dimtm = dimtp * (1 + 1.e-10)
sergey slezkin