鍍鋅方管的國標與非國標的區別——：就是管壁的實際厚度非標的都比國標的壁薄一些的。主要規格不是很標準，舉個例子：鍍鋅方管的國標與非國標的區別（1）非標的都比國標的壁薄一些的（2）非標的定尺長度也沒有達到國標；（3）非標的比國標便宜

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.