طلبات معدن حديد فولاذ / الولايات المتحدة الأمريكية

I am sourcing for manufacturers of Box Steel Welded tubes for the following Specs. A. 12.7 mm X 12.7mm X 6 meters X 20 Guage or 0.35 wall thickness ASTM 500 Grade B Steel or equivalent Grade steel in Turkey B. 12.7mm X 25.4mm X 6 meters X 20 Guage or 0.35 Wall Thickness ASTM 500 Grade B Steel or equivalent Grade steel in Turkey