co khi dai cuong:

thep hop kim ket cau cho them nguyen to hop kim.

cho phep chiu trong tai cao, can do cugn, chiu do mai mon, hoac tinh dan hoi.

- thep ket cau: S,P rat nho, tinh nang hoa ly tot,ham luong C thuat tien.

-thep cac bon dung cu: ham luong c cao 0,7-1,4%. chiu nhiet thap