Insights · Reference
A TDF (Transverse Duct Flange) connection is rolled into the duct itself, not bolted on as a separate angle. This reference lists the four SBKJ machines that produce TDF duct — the flange former, the folder, the cleat cutter and the duct zipper — with model, material thickness, power and weight taken verbatim from the SBKJ Product Catalog 2026.
On a TDF (Transverse Duct Flange) duct, the connecting flange is roll-formed straight onto the edge of the sheet, so it is part of the duct rather than a separate angle-iron frame riveted on afterwards. SBKJ rolls a 35 mm flange. Two duct sections then bolt or clip together flange-to-flange with corner pieces, which is faster to install and seals better than a built-up angle flange. Compare the two methods in our TDF vs angle flange guide; this page is about the machines that make it.
A TDF duct passes through four operations. Each can run as a standalone station or be combined into a line. The table lists every machine with the figures from the SBKJ catalog.
| Machine | Role in the TDF line | Model(s) | Material thickness | Power | Weight |
|---|---|---|---|---|---|
| TDF flange former | Roll-forms the integral 35 mm flange onto the sheet edge | SBTDF-12 SBTDF-1.5-16 | 0.5–1.2 mm 0.8–1.5 mm | 2.2 kW 4 kW | 760 kg 910 kg |
| TDF metal folder | Folds the flanged sheet into the rectangular duct box (90°–180°) | SBWS 1.5×1500TDF SBWS 1.2×2000TDF | 0.4–1.5 mm 0.4–1.2 mm | — | 318 kg 418 kg |
| TDF cleat cutter | Cuts the corner cleats that lock the four TDF corners | TDF cleat cutting machine | 0.5–1.2 mm 0.8–1.5 mm | 3 kW 4 kW | 850 kg 900 kg |
| TDF duct zipper | Closes the longitudinal seam, up to 15 m/min | SBHF-1.5×1500TDF | 0.5–1.5 mm | 3 kW | 710 kg |
Source: SBKJ Product Catalog 2026, manufacturer nameplate specifications. TDF flange height 35±0.5 mm. All machines run 380 V / 50 Hz / 3-phase (60 Hz on request). The folder is a mechanical fold and is not listed with a drive motor. Two figures in a cell are the two model variants in the same order as the Model column.
1. Form the flange. The blank passes through the TDF flange former, which rolls the 35 mm transverse flange onto the two edges that will become the duct ends. The SBTDF-12 covers 0.5–1.2 mm; step up to the SBTDF-1.5-16 for galvanised up to 1.5 mm.
2. Cut the corner cleats. The cleat cutting machine notches the corner cleats so the four corners can be locked square once folded.
3. Fold the box. The metal folder bends the sheet through 90°–180° into the rectangular duct section. The SBWS 1.5×1500TDF folds up to 1.5 mm at 1500 mm; the SBWS 1.2×2000TDF trades thickness for a wider 2000 mm fold.
4. Close the seam. The TDF duct zipper closes the longitudinal seam at up to 15 m/min, down to Φ100 mm equivalent, and the duct is finished with an integral flange at each end ready to bolt to the next section.
The deciding number is your heaviest gauge. If you fabricate galvanised up to 1.5 mm, pair the SBTDF-1.5-16 former with the SBWS 1.5×1500TDF folder. If your work tops out at 1.2 mm but you need wider blanks, the SBTDF-12 former with the SBWS 1.2×2000TDF folder gives you the 2000 mm fold. The cleat cutter and duct zipper cover the full 0.5–1.5 mm range either way. For high volume, the same TDF flange is produced on a fully integrated auto duct line, where forming, notching, folding and seam closing happen in one pass.
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TDF (Transverse Duct Flange, also called integral flange or TDC) is a flange roll-formed directly onto the edge of the duct sheet, so the connecting flange is part of the duct rather than a separate bolted angle. SBKJ rolls a 35 mm (±0.5 mm) TDF flange. Ducts join flange-to-flange with corner pieces and clips — faster to install and lower-leak than a built-up angle flange.
Four: a TDF flange former (SBTDF-12 or SBTDF-1.5-16) that rolls the 35 mm flange, a metal folder (SBWS 1.5×1500TDF or 1.2×2000TDF) that folds the box, a cleat cutter for the corner cleats, and a duct zipper (SBHF-1.5×1500TDF) that closes the seam. They run standalone or as a line.
Up to 1.5 mm galvanised on the SBTDF-1.5-16 former and SBWS 1.5×1500TDF folder. The SBTDF-12 former covers 0.5–1.2 mm and the SBWS 1.2×2000TDF folder 0.4–1.2 mm at a wider 2000 mm length.
The flange is 35±0.5 mm. The former draws 2.2–4 kW, the cleat cutter 3–4 kW and the zipper 3 kW, all on 380 V three-phase 50 Hz (60 Hz on request).
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