1 raw material difference. For example, the national standard steel is Q-235 or Q-235A, which is equivalent to A3 steel in the past, and the non-national standard steel is strip steel, which is rolled by small steel mills. Due to the production process and quality control, there are great differences between the two materials in stability and consistency, composition, mechanical and physical properties.

2 Difference in size and deviation. The size and deviation of national standard steel products are accurately controlled, which meets the requirements of relevant standards. Non-national steel is almost too small.

3 the difference between processability and heat treatment performance. Non-national standard steel is particularly poor in hardness and brittleness.

4 differences in use. Of course, the national standard steel is good, but this problem cannot be generalized, it depends on what you do with it. If you just need to make a simple shelf, it doesn't matter whether it is a national standard or not.

As for the price, the non-national standard can be at least 10% cheaper, and it is easy to get the price.