hot galvanized square pipe ASTM A 500 B (OR) S275 JR Square Hollow Sections

For circular welded pipes, the specimen must be at least 4 inches (100 millimeters) cold flattened between two parallel plates in three steps, with the weld seam at 90 ° to the direction of force.

The first step is a ductility test of the weld seam, with no cracks or fractures on the inner and outer surfaces of the sample until the distance between the two plates is less than two-thirds of the outer diameter of the pipe.

The second step is to ensure that there are no cracks or fractures on the inner and outer surfaces of the base material until the distance between the two plates is less than half of the outer diameter of the pipe, unless otherwise specified.

The third step is stability testing, and the flattening behavior continues until the sample breaks or the relative pipe wall of the sample comes into contact. Thin, insufficiently sturdy raw materials or incomplete welding will be shown throughout the flattening test, which will serve as evidence of product failure.

For seamless circular structural pipes with an outer diameter of 23/8 inches (60 millimeters) and above, the sample length should not be less than 21/2 inches (65 millimeters) and should be cold flattened between two parallel plates in two steps.

The first step is the ductility test, where there are no cracks or fractures on the inner and outer surfaces, except as specified in 10.5, until the distance between the two plates is less than the H value. The calculation formula is as follows: H=(1+e) t (e+t/D) (1), H=distance between the pressure plates, inches (millimeters), e=deformation per unit length (fixed values according to steel grade, A grade 0.09, B grade 0.07, C grade 0.06), t=specified wall thickness, inches (millimeters), E=deformation per unit length (with fixed values according to steel grade, A grade 0.09, B grade 0.07, C grade 0.06), t=specified wall thickness, inches (millimeters), D=specified pipe outer diameter, inches (millimeters)

The second step is stability testing, where the flattening behavior continues until the sample breaks or the relative pipe wall of the sample comes into contact. Thin, insufficiently sturdy raw materials or incomplete welding will be shown throughout the flattening test, which will serve as evidence of product failure.