Tolerance of size or allowable deviation of size beyond standard. The "size" here refers to the outer diameter and the wall thickness of the steel pipe. It is usually called "tolerance", which is called "tolerance". This kind of deviation is equivalent to "tolerance", and should be called "deviation"". The deviation here may be "positive" or "negative". Very few "positive and negative" deviations occur in the same batch of steel tubes.
Note: the theoretical weight calculation formulas of common profiles are calculated:
M=F * L * P
M - F - Kg; basal area m2/m; L - M - *Kg/m3 density length; P
It including: the calculation method of F fault area:
1, the steel F= A2
2, steel tube F=3.1416 x $(D-$) D - diameter $- thickness
3, steel plate, flat steel, F=, a * $a - width