... ISO cert 4,quick delivery constrution use hot dip galvanized square and rectangular steel pipe/SHS/RHS 1. Outer diameter: ... need.4. Surface treatment: bared, galvanized, oiled, painted to prevent rust.5. Technique: ERW, hot-rolled6. Certification: CE, ISO7. ... -making, railway construction, container support, furniture, decoration and steel structure construction.10. Capacity:8500 tons per month11. MOQ: ...