Being a union sheet metal worker means working under a collective bargaining agreement: SMART, your local union, and the contractors who sign that agreement set your wage scale, your benefits, and your training.
Admission runs through a four- or five-year apprenticeship at little to no tuition.
Here is what SMART is, how locals and the hiring hall work, what membership provides, and how the union route compares with non-union shops.
What is SMART?
SMART is the union sheet metal workers join, and its training arm — the International Training Institute (ITI) — is jointly sponsored by SMART and SMACNA, which represents the contractors on the other side of the table.
Both sides of the industry run the training together, which is the clearest way to picture how the union side of this trade is organized.
The ITI reports more than 14,000 registered apprentices at local training facilities in the United States and Canada, and the training itself runs through affiliated local training centers.
The program you would attend is local; the institute behind it is national.
Do not confuse SMART with the United Association (UA), the pipe trades' union.
The UA says it represents approximately 409,000 plumbers, pipefitters, sprinkler fitters, HVACR service technicians, welders, and related trades in North America.
If you are weighing SMART against the UA, you are weighing sheet metal against the pipe trades — and each union's locals, wage scales and training run separately.
What membership does for you day to day runs through your local, which is where most of the practical questions — pay, dispatch, admission — actually get answered.
How do locals and the hiring hall work?
SMART is organized into local unions, and the local is the unit you actually join: it covers its own geographic jurisdiction, it signs the agreement that sets wages and benefits for the workers under it, and it is who you deal with week to week.
Each local is identified by a name and number, and no two run things identically.
Locals are numbered and tied to a jurisdiction — SMART Local 66 in Seattle and Local 55 in Pasco, for example.
Your local's number is how you find the details that actually matter: its jurisdiction, its wage scale, its application process, its training center.
Those details belong to the local, and the only source we would send you to is the local itself — find yours through SMART and read what it publishes.
The local's hall is also where members connect with work — it is the "hiring hall" behind the phrase.
Contractors that sign the agreement ask the hall for workers, and the local refers its members under its own dispatch rules.
Exactly how those rules run — the order of the out-of-work list, how travel between locals is handled, what dues and initiation cost — was not confirmed by our research, and it varies by local.
We will not quote a general mechanic for that reason, because any one we picked would be wrong somewhere.
The local's office can answer each of these in one call.
What membership provides: pension, health coverage, and training
The benefit with the clearest public paper trail is training.
A SMART apprenticeship runs four or five years, combining on-the-job training with specialized classes, and the ITI's own description of the program is direct about cost: apprentices pay little to no tuition.
That is the training benefit in one sentence — you learn the trade on real work, with classes around it, without a tuition bill.
Pension and health coverage work differently: they come through negotiated benefit funds tied to the local's agreement, so what retirement and health actually look like depends on where you work.
We will not quote contribution rates, vesting rules or benefit amounts — there is no verified national figure, and a wrong number on this topic does real damage.
If you are comparing a local's offer, ask the hall for its current wage-and-fringe sheet and the benefit funds' summary plan descriptions.
That lets you weigh the total package — wages, health, retirement — rather than judging by the hourly rate alone.
Benefits and dues are local — verify with the local
Union vs non-union sheet metal: what actually differs
Union membership is the minority across the construction trades.
In 2025, 16.4% of employed wage-and-salary workers in construction and extraction occupations were union members, and 17.4% were represented by a union — the BLS occupation group that includes sheet metal workers.
BLS does not publish a union rate for sheet metal workers specifically, so those group figures are the honest measure of the union footprint.
The practical difference is who sets your pay and benefits.
Under a union contract, your wage scale and benefit contributions are written into the agreement your local negotiates, and they apply across the contractors who sign it.
Non-union, the shop sets them — so pay and benefits can differ from employer to employer on the same street.
At the occupation-group level, the federal numbers exist: in 2025, full-time union members in construction and extraction occupations had median weekly earnings of $1,561 against $1,004 for non-union workers in the same occupation group, per BLS.
Treat that as a raw gap — not a sheet-metal-specific rate, and not controlled for occupation mix, region, age or experience — rather than a guaranteed premium.
What you can still only compare concretely is your local's scale and benefit sheet against real offers in your market.
The work itself does not change with the card — union and non-union sheet metal workers do the same fabrication and installation described in our sheet metal worker guide.
What changes is the structure around the work.
How do you join a SMART local?
Union membership starts with admission to a local's apprenticeship — the four- or five-year, little-to-no-tuition program shape SMART's ITI describes.
Each local's joint apprenticeship committee runs its own admission, and there is no standard national format to prepare around: application steps, any testing and apprentice wage steps are set local by local.
Contact the local where you live and ask what it requires.
For the full route — eligibility, the application, and what the apprenticeship years look like — see our guide to how to become a sheet metal worker.
Union wage scales: why there is no national number
There is no national union scale for sheet metal work, so no honest page can print one.
Your rate is the hourly figure in your local's current agreement, and it is negotiated local by local — which is also why we keep scale numbers out of this page and point you to the local.
For the trade as a whole — union and non-union together — the federal wage data lives on our sheet metal worker salary page, broken out by state and metro area.
Career information, not legal advice. Union agreements, benefit funds and apprenticeship rules change — confirm current terms with the local union and its training center before you act on them.