■ Materials: Galvanized Steel Sheet, Stainless Steel Sheet ■ Size:Φ4＂～Φ60＂ ■ Feature: ? Spiral seam adopts Double Seam butt joint. ? Using of high speed automatic cutting equipment, no rough selvedge, pipe diameter accurately conform to the standard of SMACNA. ? The standard length is 3m. ISO9001:2000