Raw Edge, Slip, Collar, or Flange: Connector Ends Do Not Match

Fast answer

Stop and identify what connector each end was supposed to receive. Two correct duct sizes do not make a usable joint when the end treatments are incompatible.

What to check

1. Confirm the piece marks and current shop drawing.
2. Identify each actual end: raw, hemmed, slip, drive, flange, collar, beaded, or manufacturer connector.
3. Check whether a separate adapter or companion piece is missing.
4. Document both ends and hold the repair or remake decision for the foreman or shop.

Do not

Do not improvise a connector by cutting off reinforcement, flattening a flange, or filling the mismatch with sealant.

Ask the foreman

“These pieces are the correct size and marks, but one end is flanged and the adjoining end is raw. I checked the spool and do not see an adapter—was a connector piece missed?”

Why it matters

Connector mismatches usually indicate a missing part, wrong fabrication release, or wrong piece—not a sealing problem.