You join a steamfitters union by getting into a local's apprenticeship: UA apprenticeships are registered with the U.S. Department of Labor, combining 2,000 hours of paid on-the-job training a year with classroom instruction.
Steamfitters belong to the United Association (UA) — Local 638 in New York City and Local 602 in the Washington, DC, area are two of its steamfitter locals.
Here is how the union is organized and how to get in.
Which unions represent steamfitters
When someone says the steamfitters union, they mean the United Association (UA) — the same North American pipe trades union behind the phrase plumbers union (UA).
Steamfitters are on the UA's own list of its trades, alongside plumbers, pipefitters, sprinkler fitters, pipeliners, welders, HVACR service technicians, and the metal trades.
The organization behind that list dates its history to 1889 and says it represents approximately 409,000 plumbers, pipefitters, sprinkler fitters, HVACR service technicians, welders, and related trades across North America — a count that includes Canada as well as the United States.
You do not join the UA directly; you join one of its local unions, and the local is who you actually deal with.
The local runs the apprenticeship intake for its area, works with the union-signatory employers there, and administers the terms its members work under.
Which local covers steamfitting where you live is a local question — the next section covers the locals our research can name.
If you are still deciding on the trade itself rather than the union, start with the steamfitter career guide; this page assumes you know what the work is and covers the union around it.
Major steamfitter locals: Local 638, Local 602, and finding yours
Searches for steamfitter locals are usually searches by number — Local 638, Local 602, Local 420, and Local 449 are the numbers that come up most.
Here is what our research can confirm about each, and what it cannot.
Local 638 — New York City.
The Enterprise Association of Steamfitters Local 638 (UA) is the NYC steamfitters' union.
When a New Yorker says the steamfitters union, this is the local they mean.
Local 602 — the Washington, DC, area.
The UA locals serving Washington, DC, are Local 5 (plumbers, based in Lanham, Maryland) and Local 602 (steamfitters, based in Capitol Heights, Maryland).
Locals 420 and 449 — Pennsylvania.
The UA's own directory lists Local 420 in Philadelphia and Local 449 in Pittsburgh among its Pennsylvania locals.
What trades each of those locals covers was not part of what our research confirmed — the trade mix is a question to put to the local itself.
One more pattern matters: plenty of UA locals combine the pipe trades under one roof.
Steamfitters & Plumbers Local Union 464 (Omaha), for example, runs apprenticeships in pipefitting, HVACR and plumbing for Nebraska and 12 western Iowa counties — so the local that covers your address may be a combined plumbers-and-steamfitters local rather than a steamfitters-only one.
Beyond the locals named above, the map thins out: how many locals the UA has in total, and the jurisdiction of any local we have not named, were not confirmed by our research — they vary by local.
The UA publishes a find-a-local directory at ua.org; that directory, plus a call to the local itself, is the reliable way to find the steamfitter local for your area.
Joining a steamfitters union through apprenticeship
There are two doors into a steamfitters local, and the apprenticeship is the one with the public documentation.
UA apprenticeships are registered with the U.S. Department of Labor, and the UA describes its registered apprenticeships as including 2,000 hours of paid on-the-job training per year plus 216 hours of related classroom instruction — the UA's page does not say whether the classroom figure is annual, so treat it as a detail to confirm with the program.
The pattern matches the trade at large: BLS says most plumbers, pipefitters, and steamfitters learn their trade through a 4- or 5-year apprenticeship, with about 2,000 hours of paid on-the-job training each year plus technical instruction.
You earn a wage while you train, and classroom work runs alongside the on-the-job hours.
The second door is organizing in — unions bring experienced non-union workers into membership, and a steamfitter who already works the trade can sometimes join a local that way.
How prior experience is credited, what evaluation applies, and which classifications organize in were not confirmed by our research, and they vary by local.
The local itself is the only source for that answer.
Whichever door applies to you, the sequence is the same, and every step of it is run locally:
Find your local
Use the UA's find-a-local directory at ua.org, and confirm by phone which local covers steamfitting where you live — jurisdiction is a local matter.Ask the local's training program about intake
Application windows and any aptitude testing are set by each local's own JATC. Our research could not confirm a standard test format or application calendar, so get this year's process from the local.Apply on the local's calendar
Entry requirements change from year to year. Confirm what this year's intake asks for, and what it costs, before you apply or pay anything.Work the apprenticeship
Paid on-the-job hours plus classroom instruction — a 4- or 5-year span in the trade at large, on your local program's own schedule.
The trade-side route — entry requirements, school versus apprenticeship, and the year-by-year timeline — is covered step by step in our guide to how to become a steamfitter.
Every local runs its own entry process — confirm before you commit
Benefits and fund offices
The benefits side of membership is organized locally too.
Health, pension, and training provisions are negotiated into the agreements each local's members work under and administered at the local level — the "fund office" that steamfitter searches turn up is the office that administers a local's benefit plans.
What any specific fund provides was not something our research verified, and it is not one national package: two steamfitter locals can run genuinely different plans.
If you are weighing membership for the benefits, put concrete questions to the local and its fund office: what the current agreement provides for health coverage, what the pension provisions are, and which plan documents you will receive as a member.
Those answers, not a generic one, are the ones that will apply to you — so treat any specific figure or plan detail you read online as belonging to whichever local published it.
Steamfitter union pay scales
Union steamfitter wage rates come out of the collective agreement each local negotiates, so there is no national union scale we could quote — the scale that applies to you is your local's.
Our research also did not confirm a steamfitter-specific union pay premium, so be skeptical of any percentage figure you are quoted.
The public benchmark is federal, and it is a combined figure: BLS groups plumbers, pipefitters, and steamfitters into one occupation, SOC 47-2152, and for that combined group reported a median wage of $30.67 an hour, or $63,800 a year, in May 2025.
There is no steamfitter-only federal wage — union or otherwise.
For percentile and state-by-state tables, see the steamfitter salary page.
Career information, not legal or financial advice. Membership terms, dues, benefit and pension provisions, and apprenticeship standards are set by each local union. Confirm the details that matter to you with the local you would join.