WCL Practice Test

The WCL is the City of Los Angeles certified welder exam, run by the Licensing Section of the Los Angeles Department of Building and Safety (LADBS). To get certified by the City, a welder passes a virtual exam and a hands-on performance test. This page has free practice sets by topic and worked answers. It also lists the official fees, passing score and retake rules in one place.

WCL Exam at a Glance

What changed for WCL in 2026

• Oct 25, 2026: Delivery changed to Virtual exam on Google Meet plus hands-on performance test (previously Virtual exam on Google Meet (open- and closed-book) + hands-on performance test at an LA City-approved testing agency).^[1]

What the WCL is and how it works

According to Los Angeles Department of Building and Safety (LADBS), Licensing Section, “Examination will consist of open and closed book segments.”^[1]

The WCL certification is how the City of Los Angeles certifies welders under its Certified Welder program. The program is run by the Licensing Section of the Los Angeles Department of Building and Safety (LADBS). To get certified, you take a virtual exam held on Google Meet, and you must also pass a performance test at a Los Angeles City approved testing facility.

The virtual exam has open-book and closed-book segments. It is held on Saturdays by appointment only, and you need a score of at least 70% to pass. Each certification category is a separate exam with its own application. The application fee is $54.50, and another $65.40 is due after you pass. To get Tubular Structures certification, you must already hold Structural Steel (SSW) certification.

If you fail a Department exam, you must wait 30 calendar days before you can test again. After a second failure, the wait is 90 days and you must show proof of more training. You pay the fees again for each new exam, and no fees are refunded after a failed attempt.

A certification is valid for 3 years from the date it is issued. Renewal costs $119.90 per category every 3 years, except for semi-automatic. Categories, forms and procedures can change. Before you apply, check the current details in the LADBS certified welder application and the LADBS Certified Welder information bulletin.

Worked examples: how to reason through WCL questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: Which approach is MOST important for WCL professionals when applying technical procedures?

1. Following personal shortcuts
2. Adhering to established protocols while adapting to specific conditions
3. Using the fastest method regardless of standards
4. Applying the same technique without variation

Answer: B. Adhering to established protocols while adapting to specific conditions

Explanation:

B is correct. Welding work follows written procedures, codes and specifications. Real jobs still vary in material, joint fit-up, position and site conditions. A good welder follows the procedure and uses judgment to adjust inside its limits, never outside them.

• A is wrong: personal shortcuts skip steps that the procedure includes for quality or safety.
• C is wrong: speed never overrides the standard. A fast weld that fails inspection costs more time in the end.
• D is wrong: using one technique the same way every time ignores conditions that the procedure expects you to account for.

Rule to remember: the procedure sets the limits, and your judgment works inside them.

Example 2

Question: What is the role of shielding gas in welding?

1. Protect weld pool from contamination
2. Cool the metal
3. Add strength to weld
4. Clean metal surfaces

Answer: A. Protect weld pool from contamination

Explanation:

A is correct. Shielding gas surrounds the arc and the molten weld pool and keeps air out. Oxygen and nitrogen in the air react with molten metal and cause porosity and brittle, weaker welds.

• B is wrong: the gas is not there to cool the metal. Cooling depends on heat input and technique.
• C is wrong: the gas does not add strength directly. It protects the weld so the filler and base metal can reach their intended properties.
• D is wrong: shielding gas does not clean the surface. Remove mill scale, oil, rust and paint before you weld.

Rule to remember: shielding gas protects the pool. Cleaning the metal and choosing the filler are separate jobs.

Example 3

Question: What role does calibration play in maintaining technical accuracy for Welding Certification Los Angeles professionals?

1. It is only necessary for new equipment
2. It ensures instruments produce accurate, consistent results over time
3. It is optional for advanced professionals
4. It only matters during inspections

Answer: B. It ensures instruments produce accurate, consistent results over time

Explanation:

B is correct. Calibration checks an instrument against a known reference and corrects it. This keeps readings accurate and consistent as the tool ages, drifts or gets knocked around. In welding, this applies to things like machine meters, gas flowmeters and inspection gauges.

• A is wrong: used equipment drifts over time, which is why calibration is repeated rather than done once.
• C is wrong: experience does not fix a meter that reads wrong.
• D is wrong: a bad reading affects every weld you make, not only the ones an inspector sees.

Rule to remember: if a decision depends on a reading, the instrument behind it must be calibrated.

How to use these practice tests

Start with the official material. Read the LADBS certified welder application and the Certified Welder information bulletin. Confirm which category you are applying for, since each category has its own application and exam.

Next, take a practice set for each topic to find your weak areas. Begin with Joint Design & Weld Symbols and Blueprint Reading & Technical Drawing, since most welding work depends on symbols and drawings. Then move on to Welding Processes & Techniques, Metallurgy & Material Science and Materials & Specifications. Finish with Inspection & Quality Control, Tools & Equipment Operation, and both safety sets: Safety Regulations & OSHA Compliance and Safety Standards & Regulations.

For every question you miss, read the explanation and write the rule down in a short line. Repeat the sets for your weakest topics until your scores are well above the 70% passing mark. Some segments are closed-book, so practice recalling symbols and definitions without notes. For the open-book segments, learn where things are in your reference material so you can find them quickly.

Prepare for the performance test too. Practice the welds for your category at a shop or school before your appointment. If you fail, you pay new fees and wait at least 30 days before you can test again.

Sources & last verified

1. Los Angeles Department of Building and Safety (LADBS), Licensing Section — number of questions, passing score, exam fee, renewal (official source). “Examination will consist of open and closed book segments.” Verified Oct 25, 2026.
2. Los Angeles Department of Building and Safety (LADBS), Licensing Section — retake fee, retake policy, validity (official source). “Where fees are required, they shall be paid for each new examination. No fees paid will be refunded upon failure to pass such examination or…” Verified Oct 25, 2026.

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