Steel pipe in the length of the direction of a curve, with the number that the curvature of the curvature that is called. The curvature specified in the standard is generally divided into the following two types:

A, local bending degree: with a meter long ruler by the maximum bending in the steel pipe, measuring the chord height (mm), that is, local bending value, the unit is mm / m, that method such as 2.5mm / m The This method also applies to the curvature of the pipe end.

B, the total length of the total curvature: with a string, from the tube at both ends of tension, measuring the maximum bending height of steel pipe (mm), and then converted into length (in meters) percentage, The length of the curvature. For example: steel pipe length of 8m, measured the maximum string height 30mm, then the tube full length of curvature should be: 0.03 / 8m * 100% = 0.375%