What are the deviation classifications of SM490B steel plates?

SM490B steel plate deviation classification:
Type N deviation: positive deviation and negative deviation are equal.
Type A deviation: Determine the negative deviation according to the nominal thickness.
Type B deviation: fixed negative deviation is 0.3.
Type A deviation: fixed negative deviation is 0, and the positive deviation is determined according to the nominal thickness.

SM490B steel plate is available for additional flaw detection requirements and Z-direction performance (Z15/Z25/Z35):
Z-direction performance: It is the common name for thickness direction performance. There are special regulations for the mechanical properties of thicker steel plates in the thickness direction.