Press Brakes and Bending Machines for HVAC and Ducting

Sheet metal bending in HVAC and ducting

HVAC manufacturers and ducting contractors work mostly with thin galvanised (GI) sheet, from about 0.6 mm to 1.6 mm, plus aluminium and stainless steel for special applications. Parts are long and light: duct sections, plenums, flanges, dampers, diffusers and air handling unit (AHU) panels. Speed and the ability to bend long, thin sheet without wavy edges are more important than raw tonnage.

Typical parts

• Rectangular duct sections and transitions
• Duct flanges (TDF and angle flanges) and stiffeners
• Plenum boxes, dampers and volume control parts
• AHU casing panels and drain pans
• Diffuser and grille housings

Choosing the right machine

Thin GI sheet needs little force: 1 mm mild steel requires roughly 8 T per metre with an 8 mm V-die. That means a 30-40 T hydraulic press brake with 2000 mm length handles most duct work. Where duct sections are longer, an 80 T CNC press brake with 2500 mm length gives room for full sheets.

For simple flanging and angle bending in thin sheet, our SBM sheet metal bending machine is an economical option, up to 3000 mm length.

Pair the bending machine with a hydraulic shear: a DHSM-225 or DHSM-230 cuts thin GI sheet over 2500 or 3000 mm.

Tips for bending GI sheet

• Use a die opening of about 6-8 times thickness for thin sheet to keep the radius small and flanges short.
• Support long, thin sheets with front supports to avoid sagging and wavy edges.
• Keep tooling clean to avoid scratching the zinc coating.