A duct fabricator works in a shop, turning flat sheet metal into duct and fittings from CAD layouts; a field installer hangs that duct in the building, joins and seals it, and ties it into the HVAC system.
Same trade, one occupation code, two different jobs.
Here is where the line sits, what each day looks like, and how workers move across it.
What a shop fabricator does: layout, CAD, and the plasma table
Shop fabrication is the half of the sheet metal worker trade where duct is born.
A duct fabricator takes field measurements and the mechanical drawings, works them into shop drawings and CAD files, and turns flat sheet into straight duct, elbows, transitions, and the fittings that tie an HVAC system together.
Furnace casings and control boxes come off the same benches — both are in the federal definition's example list for the trade.
The flow repeats from job to job.
Layout comes first: the fabricator develops each fitting as a flat pattern, working out the geometry so a three-dimensional elbow or offset unfolds into a shape that can be cut from flat sheet.
Cutting follows — plasma tables, shears, and hand tools for the one-offs — then the forming equipment: brakes bend the metal, rolls curve it, and coil lines run out straight duct.
The pieces are then joined and assembled — seams closed, corners welded or mechanically locked, flanges and stiffeners added — so a fitting arrives in the field ready to hang.
Fabricators label and kit the work by system and by installation order, because field crews assemble in the sequence the building allows, not the order the shop produces.
Two things define the shop side.
The work is precision-driven: a fitting that leaves the shop out of square or off dimension becomes a field problem, so accuracy is the core skill.
And the output is shared — one shop's duct serves many field crews — which is one reason fabrication and installation show up as separate job titles inside the trade.
What a field installer does
Field installation is the half where the system goes into the building.
O*NET's definition names this side directly: the Sheet Metal Workers code includes sheet metal duct installers, who install prefabricated sheet metal duct.
Installers unload the kitted duct, stage it through the building, and hang trunk and branch lines on straps and hangers.
Sections are joined, seams and joints are sealed, and the duct connects to air handlers, furnaces, and rooftop units, with boots set where the registers and grilles land.
The craft cousin of this job is the duct installer on an HVAC crew, who runs the same hang-and-seal discipline on flex and prefabricated pieces.
The working conditions are the field's signature.
Installation happens in attics and crawl spaces, on ladders and lifts, in buildings under construction and in occupied ones, and the schedule follows the construction sequence — duct goes in during rough-in, before the walls close.
Repair is the other mode: pulling failed sections and tying replacements into the existing system.
Where the shop works to the drawing, the field works to the building: hanger points land where the structure allows, and a route that was clean on paper can end up rerouted around a beam.
Installers feed those field conditions back to the shop, so the next fitting can be fabricated to the building rather than only to the drawing.
Schedule, conditions, and pay
Hours read trade-wide rather than by half.
In O*NET's survey, 72% of sheet metal workers report a typical week of 40 hours and 28% report more than 40 — a trade that mostly runs standard weeks, with a meaningful minority on longer ones.
The survey covers sheet metal workers as one occupation, so treat those figures as trade-wide, not shop-specific or field-specific.
Pay has the same shape.
BLS publishes one occupational code for the trade, Sheet Metal Workers (47-2211), so there is no separate federal wage for shop fabricators or field installers.
The trade-wide figures, from the OEWS May 2025 survey (released May 15, 2026): a median of $29.71 per hour, or $61,800 per year, and a mean of $32.62 per hour ($67,850 per year).
The 10th percentile earned $18.57 per hour ($38,630 per year); the 90th earned $50.79 per hour ($105,650 per year).
Two reads worth adding.
Within NAICS 238220 — plumbing, heating, and air-conditioning contractors, the industry category that covers the mechanical contractors who install building HVAC — the trade's median was $69,830 across 51,680 wage-and-salary jobs.
And the survey measures base pay: overtime, shift differentials, and nonproduction bonuses are excluded from OEWS figures, so real annual earnings can exceed them for workers who put in extra hours.
The full state-by-state tables are on our sheet metal worker salary page.
No shop-vs-field wage exists in federal data
Moving between shop and field
The two halves sit in one trade, not two careers — one occupation code covers fabrication and installation together — so a move between them is a change of assignment more than a change of trade.
The employers overlap, too: Building Equipment Contractors, the industry that employs the most sheet metal workers (53,690 in May 2025), is where fab shops and field crews work for the same payroll, and a contractor running both can move a worker across the shop threshold without leaving the company.
Apprenticeship is the structured route into the trade.
In the shape SMART's International Training Institute describes, sheet metal apprenticeships run four or five years; the ITI is jointly sponsored by SMART and SMACNA, the contractors' association, and counts more than 14,000 registered apprentices across the US and Canada.
Skills carry in both directions.
Shop work builds layout and measurement discipline and fluency with drawings; field work adds rigging, coordination with other trades, and the building-context judgment that makes shop drawings better.
Which half you start on can come down to what the hiring contractor needs when you apply — a fair question to ask in the interview.
As a rule of thumb when you search: shop openings run under duct fabricator, field openings under installer and duct installer — and both halves hire under the sheet metal worker umbrella.
Manufacturing fabricator vs construction sheet metal
"Sheet metal fabricator" reaches beyond the duct trade — it is as much a manufacturing title as a construction one.
In manufacturing, workers form enclosures, appliances, and equipment components in production settings, and that slice of the trade is large: Fabricated Metal Product Manufacturing employed 20,780 sheet metal workers in May 2025.
The construction side is bigger.
Building Equipment Contractors — the mechanical contractors who install building HVAC — employed 53,690 sheet metal workers, the most of any industry, and Foundation, Structure, and Building Exterior Contractors employed another 16,060 in roofing and architectural sheet metal.
The whole occupation came to 119,770 wage-and-salary jobs in May 2025, and it all counts under one federal code — one reason the trade's statistics read as blends.
For someone targeting HVAC duct work, the distinction is practical.
In construction, duct fabricator is the shop-side title to search for, and "sheet metal fabricator" in a mechanical contractor's posting describes the same job covered above.
In manufacturing, the same title means production sheet metal work — a different product, pace, and employer.
The industry line in a posting — contractor versus manufacturer — tells you which world the job sits in.
Career information, not legal advice. Pay figures are BLS wage-survey data, not an offer benchmark. Where licensing applies to sheet metal work where you live, confirm current requirements with your state licensing board or the city or county office where licensing is local.