Est. 1966 — Serving NC & SC Contractors — (704) 201-9127

Product Line

Every fitting your crew needs, from one shop

Rectangular duct, spiral pipe, welded black iron, roof curbs, drain pans and one-off specialties — fabricated to your prints, labeled by job and floor, and delivered on SWI trucks.

SWI crew packing labeled galvanized boots, collars and drain pans for contractor delivery
RECTANGULAR DUCTWORKSPIRAL PIPEBLACK IRON EXHAUSTROOF CURBSDRAIN PANSCUSTOM FITTINGSSMACNA CERTIFIEDEST. 1966NC & SC DELIVERYRECTANGULAR DUCTWORKSPIRAL PIPEBLACK IRON EXHAUSTROOF CURBSDRAIN PANSCUSTOM FITTINGSSMACNA CERTIFIEDEST. 1966NC & SC DELIVERYRECTANGULAR DUCTWORKSPIRAL PIPEBLACK IRON EXHAUSTROOF CURBSDRAIN PANSCUSTOM FITTINGSSMACNA CERTIFIEDEST. 1966NC & SC DELIVERYRECTANGULAR DUCTWORKSPIRAL PIPEBLACK IRON EXHAUSTROOF CURBSDRAIN PANSCUSTOM FITTINGSSMACNA CERTIFIEDEST. 1966NC & SC DELIVERY

Technical Catalog

Rectangular Ductwork

TDF / TDC

SMACNA-compliant rectangular duct fabricated on automated coil lines. TDF/TDC flanged connections, 26–20 gauge galvanized, lined or unlined, sealed to SMACNA Seal Class A.

  • 26–20 GA galvanized
  • TDF/TDC or slip & drive
  • Duct liner & wrap options
  • SMACNA Seal Class A

Spiral Pipe & Fittings

ROUND / FLAT OVAL

Spiral lock-seam round and flat-oval pipe with matching elbows, tees, reducers and taps. Gored, stamped or radiused fittings to spec for exposed architectural ceilings.

  • 4"–60" diameters
  • Spiral & longitudinal seam
  • Double-wall available
  • Architectural finish ready

Black Iron & Grease Duct

WELDED

Heavy-gauge welded black iron duct for kitchen exhaust, industrial exhaust and smoke control. Continuous welded seams, NFPA 96 compliant for commercial kitchen grease duct.

  • 18–10 GA black iron
  • Continuous TIG/MIG welds
  • NFPA 96 grease duct
  • Flanged & companion angle

Drain Pans & Plumbing Metal

CUSTOM

Custom condensate drain pans, water heater pans and plumbing sheet metal built to your dimensions. Soldered or welded corners, PVC or threaded drain connections.

  • Galvanized or stainless
  • Any size to 96"
  • Welded watertight seams
  • Custom drain locations

Roof Curbs & Flashing

WEATHERPROOF

Equipment roof curbs, curb adapters, pitch pockets and counter flashing fabricated to RTU submittals. Fully welded and reinforced for carrier and package units.

  • 18–20 GA galvanized
  • Welded & reinforced corners
  • Curb adapters to spec
  • Wood nailer options

Custom Fittings & Specialty

MADE TO ORDER

Transitions, offsets, elbows, boots, collars, wyes and one-off specialty sheet metal. Send a sketch or a CAD file — our shop builds it to the print, labeled by job and floor.

  • CAD/CAM plasma cutting
  • Job & floor labeling
  • Stainless & aluminum
  • Rush turnaround available

Materials, gauges & fabrication standards

Every SWI product starts with certified coil stock — hot-dipped galvanized steel in 26 through 10 gauge, 304 and 316 stainless steel for corrosive and coastal environments, aluminum for weight-sensitive applications, and black iron for welded kitchen and industrial exhaust. All ductwork is fabricated to current SMACNA construction standards, with joints sealed to SMACNA Seal Class A and every fitting checked against the CAD print before it leaves the shop.

Not sure which gauge or material your specification calls for? Send the prints — our estimators will confirm the requirements and flag any value-engineering options that save material without compromising performance.

Plan Your Order

Know your weight before you quote

Use the estimator to size up a duct run's surface area and material weight, then send us the prints for a firm number. Need a full takeoff? Our estimators do them free for NC & SC contractors.

Request a Full Takeoff

Contractor Tool

Duct Weight & Surface Estimator

Surface Area

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Est. Weight

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Estimates based on galvanized sheet weights per SMACNA tables. For exact totals, request a takeoff.