Ask when connector type, gasket, cleat/bolt schedule, pressure class, or manufacturer detail is unclear.
Watch out
Do not lift flanged duct and then go hunting for the parts.
Check
Lay out gasket, corners, clamps, bolts, nuts, washers, and tools
Confirm hardware matches the joint
Steps
Align the duct sections square.
Check flange faces, corners, gasket, and cleats/bolts.
Fix damage or missing parts before tightening.
Tighten or cleat evenly per project/manufacturer detail.
Focus on the actual issue: not staging flange hardware before duct is in air.
Say this to your foreman
In Rectangular Duct Assembly: TDC / Ductmate / Flanges, I'm looking at: Not staging flange hardware before duct is in air. What should I verify before I cut, drill, seal, cover, move, or install?