Welding Interview Questions 2026: What Supervisors Actually Ask

Welding interviews are some of the most straightforward job interviews you'll ever have - because the person interviewing you almost certainly knows how to weld. You're not talking to a recruiter who doesn't understand the difference between MIG and TIG. You're sitting across from a shop supervisor, a foreman, or the owner of a fabrication company who's been burning wire for 20 years. They can tell within two minutes whether you know what you're doing.

That works in your favor if you have real skills. Welding interviews don't reward corporate buzzwords or rehearsed answers. They reward practical knowledge, safety awareness, and the ability to explain your experience without exaggerating. Whether you're a fresh graduate from a vocational program or a certified welder switching shops, this guide covers the questions you'll actually face and how to answer them well.

If you're wondering about the money side, our welder salary guide breaks down what shop welders, pipe welders, and underwater welders actually earn in 2026. And if you want a general overview of preparing for any interview, start with our complete interview preparation guide first.

How Welding Interviews Work (What to Expect)

Welding interviews usually have two parts that other industries don't: the conversation and the weld test. Most other jobs just ask questions. Welding shops want to see you put metal together.

The Conversation

This is the traditional interview portion. It's usually short - 15 to 30 minutes in most shops. The interviewer wants to understand your experience, what processes you know, what positions you're comfortable welding in, and whether you'll show up on time. Small shops might do this in the foreman's office. Larger operations might have you meet with HR first, then the welding supervisor separately.

The Weld Test

Many employers require a weld test before or after the interview. This is your chance to prove what you claimed in the conversation. The test varies depending on the company:

Structural shops - typically a groove weld (1G or 3G) and maybe a fillet weld, usually FCAW or SMAW
Pipe shops - a 6G pipe weld (the hardest position - if you can do 6G, you can do anything below it)
TIG shops - a TIG weld on stainless or aluminum, evaluated for appearance, penetration, and consistency
Production facilities - may just have you run some beads on a coupon to check speed and quality

Some tests are pass/fail visual inspections. Others go to X-ray or bend testing. If you're applying for code work (structural steel, pressure vessels, pipelines), expect the test to follow AWS D1.1 or ASME Section IX standards.

Union vs. Non-Union

Union welding jobs (through the Ironworkers, Boilermakers, Pipefitters, or UA locals) have a more structured interview and qualification process. You'll typically need to pass a skills assessment and may be ranked on a list. Non-union shops tend to be more informal - sometimes you walk in, talk to the foreman for 10 minutes, do a weld test, and get an answer the same day. The trades and skilled labor industry is hiring aggressively right now regardless of union status.

Entry-Level and Apprentice Questions

If you're coming out of a trade school, community college welding program, or just getting started, these are the questions you'll hear. The interviewer knows you're green. They're evaluating your foundation and your attitude.

"What welding processes are you trained in?"

Be specific and honest. Name the processes you've actually run: SMAW (stick), GMAW (MIG), FCAW (flux core), GTAW (TIG). Don't just list acronyms - mention what materials and positions you've practiced. "I completed a 900-hour program where I ran stick and MIG on mild steel in all positions, and I did about 80 hours of TIG on stainless" is much better than "I can do all of them."

If you haven't touched a specific process, say so. "I haven't done any aluminum TIG yet, but I'm confident I can pick it up quickly because my stainless TIG work was solid" is honest and shows self-awareness.

"Why did you choose welding?"

This is the trade-school equivalent of "tell me about yourself." Have a real answer. Maybe you took a shop class in high school and it clicked. Maybe you're making a career change from a desk job and want to build things with your hands. Maybe you watched your uncle weld growing up and it always fascinated you. Whatever it is, make it genuine. What they're really asking is whether you'll stick with this when the work is hot, repetitive, and physically demanding.

"What positions can you weld in?"

If you know your positions, state them clearly: 1G (flat), 2G (horizontal), 3G (vertical), 4G (overhead), and for pipe: 1G, 2G, 5G, 6G. Be honest about which ones you're strong in and which ones you're still developing. Overhead (4G) and 6G pipe are the hardest - if you're good at those, say so. If you've only done flat and horizontal, that's fine for many production welding jobs, but don't claim more than you can deliver.

"Do you have any certifications?"

If you have AWS certifications (like D1.1 Structural, D1.5 Bridge, or ASME qualifications), list them with the specific test configuration. If you don't have certs yet, mention what testing you've done in school and your plans to get certified. Many shops will qualify you in-house anyway, but having certifications shows you've already proven your skills under pressure.

"Are you comfortable with physical work in extreme conditions?"

Welding is physically brutal some days. You're working in full leathers in 100-degree heat. You're lying on your back under a structure welding overhead while sparks rain down on you. You're climbing into confined spaces on a shutdown project. You need to answer yes honestly - and mean it. If you've handled similar conditions in previous work, mention it.

Experienced Welder Interview Questions

If you've been welding for a few years or more, the questions shift from "can you do this" to "how well do you do this and what have you done."

"Walk me through your welding experience."

Don't give a vague answer. Be specific about the types of work you've done:

What processes? (Stick, MIG, TIG, flux core, sub-arc)
What materials? (Carbon steel, stainless, aluminum, chrome-moly, Inconel)
What industries? (Structural, pipe, shipbuilding, aerospace, automotive, manufacturing)
What positions? (All-position? Pipe? Specialty?)
What codes? (AWS D1.1, ASME IX, API 1104)
Any notable projects? ("Welded structural connections on a 12-story building downtown" or "Ran TIG root passes on high-pressure steam pipe at the refinery")

The more concrete details you give, the more credible you are. This is also a chance to mention any specializations - if you're one of the few people in your area who can weld stainless exhaust systems or repair cast iron, say so.

"What's your reject rate?"

If you've done code work, you should know your reject rate. This is the percentage of your welds that fail X-ray, ultrasonic testing, or bend tests. A good welder runs under 2-3% rejects. If yours is low, state it proudly: "My reject rate over the last two years has been about 1.5% on X-ray." If you don't know your exact number, say so and explain that you've consistently passed inspections.

"How do you set up your machine for [specific process/material]?"

This is a practical knowledge test. They might ask about MIG settings on 1/4" steel, TIG settings on .065" stainless, or stick rod selection for different applications. A solid answer includes: wire/rod type and diameter, gas mixture and flow rate (if applicable), amperage range, voltage, travel speed, and any special considerations like pre-heat or interpass temperature.

Example: "For MIG on 1/4" mild steel, I'd run .035 ER70S-6 wire, 75/25 argon/CO2 at about 35 CFH, somewhere around 200-210 amps and 24-25 volts for a single pass fillet. I'd adjust from there based on how the puddle looks."

"Tell me about a time you had to fix a bad weld."

Everyone's had to do repairs. This is a challenge question in disguise. Describe the situation: what was wrong with the weld (porosity, undercut, incomplete fusion, crack), how you identified the problem, what caused it, and how you fixed it. The best answers show you understand root cause analysis, not just grinding and re-welding. "The porosity was caused by contaminated gas - the regulator had moisture in it. I replaced the regulator, re-prepped the joint, and re-welded. It passed X-ray on the second attempt."

"What welding symbols can you read on a blueprint?"

Blueprint reading separates production welders from skilled tradespeople. You should be able to identify fillet welds, groove welds (V, J, U, bevel), weld-all-around, field weld, backing bar, melt-through, and finish symbols. If you can read a welding procedure specification (WPS) too, mention it. "I'm comfortable reading AWS standard welding symbols and I reference the WPS for every code job" is a strong answer.

Technical Questions

These questions test whether you understand the science behind what you do, not just the muscle memory.

"What's the difference between MIG, TIG, stick, and flux core?"

This sounds basic, but they want to hear you explain it clearly:

SMAW (Stick) - uses a consumable electrode coated in flux. Versatile, works outdoors in wind, good for structural and pipe. Slower and produces slag that needs chipping.
GMAW (MIG) - wire-fed, shielded by external gas. Fast, clean, good for production work. Doesn't work well outdoors because wind disrupts the gas shield.
FCAW (Flux Core) - wire-fed like MIG but the flux is inside the wire. Can be self-shielded (no gas needed) or dual-shielded (gas + flux). Great for structural steel and outdoor work.
GTAW (TIG) - non-consumable tungsten electrode, separate filler rod, argon shielding. Slowest but highest quality. Used for stainless, aluminum, chrome-moly, and any application where appearance and precision matter.

"What causes porosity in a weld, and how do you prevent it?"

Porosity means gas pockets trapped in the weld metal. Common causes: contaminated base metal (oil, rust, paint, moisture), insufficient shielding gas flow, drafty conditions blowing gas away, moisture in flux-coated electrodes (especially low-hydrogen rods), and excessive travel speed that doesn't let gas escape before the puddle solidifies.

Prevention: clean the base metal properly (grind, wire brush, solvent wipe), check gas flow rate, use windscreens outdoors, store electrodes in a rod oven, and maintain consistent travel speed.

"What is hydrogen cracking and how do you prevent it?"

Hydrogen-induced cracking (also called cold cracking or delayed cracking) happens when hydrogen gets trapped in the weld and diffuses into the heat-affected zone. It's most common in thick sections of high-strength steel. Prevention involves three things: use low-hydrogen electrodes (E7018 for stick, or low-hydrogen flux core wire), preheat the base metal to slow cooling and allow hydrogen to escape, and maintain proper interpass temperatures. Also, keep low-hydrogen rods in a rod oven at 250-300°F - if they've been exposed to humidity, rebake them per the manufacturer's instructions.

"What's the purpose of pre-heat, and how do you determine the temperature?"

Pre-heat slows the cooling rate of the weld and surrounding base metal, which reduces the risk of cracking in the heat-affected zone. Thicker materials, higher-carbon steels, and high-restraint joints need more pre-heat. The required temperature comes from the WPS (welding procedure specification), which is based on the material composition, thickness, and applicable code. Common pre-heat for structural steel starts around 200°F for thicker sections. You verify the temperature with a temperature-indicating crayon (like a Tempilstik) or an infrared thermometer.

"Explain the difference between destructive and non-destructive testing."

Non-destructive testing (NDT) evaluates welds without damaging them: visual inspection, X-ray (radiographic), ultrasonic, magnetic particle, dye penetrant, and phased array. These methods find defects while leaving the weld intact.

Destructive testing physically breaks the weld to evaluate it: bend tests, tensile tests, macro etch, and nick break tests. These are used for procedure and welder qualification - you sacrifice test coupons to prove the weld meets strength and ductility requirements.

Quick-Fire Technical Questions

Question	What They're Testing
What rod do you use for general structural welding?	E7018 knowledge (low-hydrogen, all-position)
What gas do you use for MIG welding mild steel?	75/25 Argon/CO2 (or C25)
What gas for TIG on stainless?	100% Argon, with back purge on pipe
What does the "70" in E7018 mean?	70,000 PSI tensile strength
What's the difference between AC and DC polarity?	DC+ for deeper penetration (most stick/MIG), AC for aluminum TIG
What's undercut and what causes it?	A groove melted into the base metal at the weld toe - excess amperage or wrong angle
What's an interpass temperature?	Max temp between weld passes, per WPS

Safety Questions

Safety in welding isn't abstract. You're working with extreme heat, toxic fumes, UV radiation, and sometimes confined spaces with limited ventilation. Every interviewer will ask at least one safety question.

"What PPE do you wear when welding?"

At minimum: welding helmet with proper shade lens (shade 10-13 for arc welding, depending on amperage), fire-resistant clothing or leathers, welding gloves, steel-toed boots, and safety glasses under the helmet. For specific situations: a respirator for galvanized steel, stainless, or any material that produces toxic fumes. Hearing protection in noisy shops. Hard hat and fall protection on construction sites. Mention that you check your helmet lens for cracks before each shift - a cracked lens means UV exposure.

"How do you handle welding in a confined space?"

Confined space welding is one of the most dangerous operations in the trade. You need a confined space permit, a spotter (hole watch) stationed outside the space at all times, continuous ventilation to manage fumes and maintain breathable air, a gas monitor testing for oxygen levels and combustible gases, and a rescue plan. You never enter a confined space without verifying all these are in place. If any readings go outside safe parameters, you stop work and evacuate immediately.

"What do you do if you notice a coworker welding without proper PPE?"

Say something. You don't look the other way and you don't wait for a supervisor to notice. Pull them aside privately if possible and let them know. If they refuse, involve the foreman or safety officer. The right answer shows that safety isn't just about protecting yourself - you look out for the whole crew. Nobody wants to work with someone who watches a coworker get a flash burn and says nothing.

"Describe your approach to fire prevention when welding."

Check your work area before you strike an arc. Remove or cover combustible materials within 35 feet (per OSHA standards). Have a fire extinguisher within reach - not somewhere down the hall. Use welding blankets or fire-resistant barriers when you can't remove combustibles. And here's the one people forget: maintain a fire watch for at least 30 minutes after you finish welding. Most welding fires don't start while you're welding - they start after you walk away, when a smoldering spark finally catches.

Behavioral Questions

These questions evaluate how you work with others and handle real job-site situations. They carry more weight than you'd think - a skilled welder who causes problems is worse than an average welder who's reliable. For a deeper look at structuring these answers, check our behavioral interview guide.

"Tell me about a time you had a conflict with a coworker."

Fabrication shops and job sites have strong personalities. Disagreements happen over who uses the overhead crane next, whose welding booth is cleaner, or whether someone's weld quality is holding up the production line. Show that you handle conflict by communicating directly, keeping it professional, and not letting it affect the work. Don't badmouth anyone by name.

"Describe a time you caught a mistake before it became a bigger problem."

This is a chance to show attention to detail. Maybe you noticed a joint was tacked up backwards before the final weld. Maybe you caught that someone was using the wrong filler metal for a code job. Maybe you read the blueprint and realized the dimensions on a cut list were off. Explain what you noticed, how you addressed it, and what would have happened if you hadn't caught it. Welding mistakes are expensive - grinding out a bad weld on a pressure vessel can cost thousands in labor and delay.

"How do you handle it when the work is repetitive?"

A lot of welding is repetitive. Production welding means running the same joint hundreds of times a day. Be honest that it can get monotonous, but explain what you do to stay focused: maintaining consistent technique, setting quality standards for yourself, staying aware of your body mechanics to prevent injury, and taking pride in each weld even when it's the 200th one that shift. The interviewer wants to know you won't get sloppy when the novelty wears off.

Specialty Welding Questions

If you're interviewing for specialized work, expect deeper questions in that niche.

Pipe Welding

"Can you run a root pass with open root?" (They want to know if you can weld without a backing ring - this is the mark of a skilled pipe welder)
"What's your experience with 6G position?" (The universal test position for pipe - if you pass 6G, you qualify for all positions)
"Have you worked to ASME Section IX or API 1104?" (Code qualification - ASME for pressure vessels and power piping, API for pipelines)
"What filler metals have you run on chrome-moly pipe?" (ER80S-B2 for TIG, E8018-B2 for stick - shows you know specialty alloys)

Structural and Ironwork

"What's your experience with moment connections?" (Full-penetration groove welds on beam-to-column connections - high-consequence work)
"Have you done any seismic welding?" (Requires special qualifications and procedures per AWS D1.8)
"Can you weld vertical up on a multi-pass groove weld?" (Tests your all-position capability on thick structural members)

TIG Specialty

"What's your experience with back purging?" (Filling the backside of stainless or chrome-moly pipe with argon to prevent oxidation)
"Have you welded thin-wall tubing?" (.035" to .065" wall - requires precise heat control and gas coverage)
"What tungsten do you prefer and why?" (2% thoriated, 2% ceriated, 2% lanthanated - each has different characteristics. Show you've thought about it, not just grabbed whatever was in the box)

What to Bring to a Welding Interview

Resume - Keep it to one page. List processes you know, materials you've welded, certifications, and major projects. Use a clean resume format and focus on concrete experience. If you need help structuring it, our resume summary guide shows how to nail the top section.
Copies of certifications - AWS certifications, ASME qualifications, any weld procedure qualifications (PQR/WPQ). Bring originals and copies.
Your own welding hood - If there's a weld test, bring your own helmet. You perform better with equipment you're used to. Plus, it shows you're invested in the trade.
Photos of your work (optional but powerful) - If you have pictures of clean welds, completed projects, or X-ray results, keep them on your phone. Nothing proves your skills like visual evidence.
References - Former shop supervisors, foremen, or welding instructors who can vouch for your skill and reliability. Format them using our reference list guide.
Valid driver's license - Field welders often drive company trucks. Shop welders still need reliable transportation to make the 5 or 6 AM start time.

Questions to Ask the Interviewer

Always have questions ready when they ask. Good questions show you're evaluating the job as much as they're evaluating you. For more ideas, see our full guide on questions to ask at the end of an interview.

Strong questions:

"What processes does the shop primarily run?" (Shows you want to know what your days will look like)
"What materials do you work with most?" (Tells you whether you'll be running mild steel all day or working with exotics)
"Is the work mostly production, fabrication, or field?" (Huge difference in day-to-day work)
"What does the welding test involve?" (If they haven't mentioned it, you should ask - it shows confidence)
"Do you provide ongoing training or certification support?" (Shows career investment)
"What's the overtime situation like?" (Legitimate question - many shops run 50-60 hour weeks during busy periods)

Questions to avoid:

"Can I wear earbuds while welding?" (Major red flag for safety awareness)
"How soon can I take vacation?" (Save this for after the offer)
Anything negative about your current or previous shop

What to Wear to a Welding Interview

You don't need a suit. That would actually be weird in most welding shops. Wear clean work clothes or business casual: clean jeans or work pants, a collared shirt or clean t-shirt, closed-toe boots. No holes, no grease stains, no offensive graphics. If there's a weld test the same day, you might want to bring your leathers and work boots in a bag. For more on interview attire across different industries, check our what to wear guide.

The point is to look like someone who takes care of themselves and their equipment. That translates directly to how you treat your work.

Common Mistakes That Cost Welders the Job

Claiming processes or positions you can't actually run - The weld test will expose this in about 5 minutes. It's better to say "I'm strong in flat and horizontal MIG, and I've been practicing vertical" than to claim all-position and then fail the test.
Trashing your previous employer - The welding world is smaller than you think. Fabricators and contractors know each other. Keep it professional, even if your last shop was terrible.
Not knowing your own reject rate or work history - If you've done code work and can't tell the interviewer your approximate reject rate or what codes you've worked to, it suggests you don't pay attention to quality metrics.
Showing up unprepared for the weld test - If you know there's a test, practice the night before. Check your hood lens, bring your own gloves, and make sure your stinger grip is comfortable. Nerves affect welding more than most people realize.
Not asking about safety culture - Shops that cut corners on safety cut corners on other things too. A good welder should care about whether the shop has proper ventilation, maintains equipment, and follows confined space procedures.
Being late - Welding shops start early. If you can't make a 9 AM interview on time, they'll assume you won't make a 5:30 AM shift either.
Overconfidence about skills - Even the best welders learn on every job. Every material, every joint configuration, every position teaches you something. Arrogance in an interview signals someone who won't take direction well on the shop floor.

The Bottom Line

Welding interviews are refreshingly practical. You talk about what you can do, and then you prove it. The shops that are hiring right now - and there are a lot of them - want welders who know their craft, prioritize safety, and show up ready to work. If you can walk in with confidence, answer technical questions honestly, and lay down a clean bead on the test, you're going to get offers.

The money is solid and the demand keeps growing. Welders are among the highest-paid workers who don't need a four-year degree, and specialty certifications can push your earnings even higher. If you're thinking about negotiating your starting pay, know that experienced welders have real leverage right now - shops are competing for talent.

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