镀锌方管的国标与非国标的区别——：就是管壁的实际厚度非标的都比国标的壁薄一些的。主要规格不是很标准，举个例子：镀锌方管的国标与非国标的区别（1）非标的都比国标的壁薄一些的（2）非标的定尺长度也没有达到国标；（3）非标的比国标便宜

The difference between the national standard and the national standard of galvanized square pipe is that the actual thickness of the pipe wall is thinner than that of the national standard. The main specifications are not very standard. For example, the difference between the national standard and the national standard for galvanized square tubes (1) the non-standard is thinner than the national standard (2) the non-standard length is not up to the national standard; (3) the non-standard is cheaper than the national standard.