hollow section:

1)L 28*28*0.55 mm         38*38*0.55 mm

2)T 28*28*0.55 mm         38*38*0.55 mm

3)Z 28*28*0.55 mm         38*38*0.55 mm

4)Material of window or door frame

5)Min thickness can be 0.4 mm or less

6)Black Annealed Steel or Bright

7)ERW steel tube & pipe are our main exporting production

8)Round, square ,and rectangle shape are all offered

9)Usage:widely used in many constructions