DVAC - Duct Ventilation Air Conditioning Co. w.l.l. has in its stock all kinds of materials with different thicknesses (Aluminum Stucco, Stainless Steel, Galvanized, Black Steel)
In addition, DVAC has large quantity of Flanges & Corners (VENTO):

VENTO Flanges
All Duct Connectors are according to DW144 & SMACNA Standard Specifications. Vento flanges are stressed so as to provide uniform pressure over the entire length of the joint Vento Flanges comes in three sizes:
System 20: Height: 20mm For Small Ducts and Low Operating Pressures
System 30: Height: 30mm For all Ducts with Low to Medium Operating Pressures
System 40: Height: 40mm For Big Size Ducts with High Operating Pressures

VENTO Corners
Corners are used for making duct frames and tested according to DIN 24194 and HVAC DW/TM1 Standard Specifications. Corners comes in two sizes:
System 30: For any Duct size out of stamped sheet steel, galvanized
System 40: For large Duct sizes out of cold-drawn, galvanized sheet metal 5m. Lengths