C-60 Welding exam questions, with answers

10 practice questions for the CSLB Welding trade exam, each with the answer, a plain explanation and the source it rests on.

From our free C-60 test · Updated 14 October 2026

These are not real exam questions. CSLB does not release its test questions or answer keys, and nobody else has them. We write our own questions from the C-60 outline and the codes, standards and references CSLB lists for the exam. Each answer names its source so you can check it.

The C-60 exam has 5 sections. The questions below are grouped by section, with the share of the exam each one carries. Read the question, pick an answer, then open “Show the answer”. The other questions of the free test, scored section by section, are in the free 25-question C-60 test.

Planning and Estimating · 17% of the exam

Reviewing plans and specifications; estimating equipment and materials; identifying metals.

1. A shop drawing for a stair landing shows fillet weld symbols both above and below the reference line, but 5/16 is written only beside the lower symbol. According to the Marine Corps welding course MCI 13.32f, how should your welder size the welds?

  1. 5/16-in fillet welds on both the arrow side and the other side
  2. A 5/16-in fillet on the other side; the arrow side gets a seal weld only
  3. 5/16 in in total, split into two 5/32-in fillets, one per side
  4. A 5/16-in fillet on the arrow side; the other side is sized by the welder
Show the answer

Answer: A. MCI 13.32f explains that when the fillet welds on both sides of a joint are the same size, the size is written on one side only, and it applies to both welds. So both fillets are 5/16 in. When the two sides differ, a size is written for each side; a size is never split between the welds.

Source: MCI 13.32f, Study Unit 6, fillet welding symbols (size of the fillet weld)

2. A drawing for a steel muffler housing calls for joining the flanged edges of two parallel sheet-metal pieces along those edges. According to U.S. Army TM 9-237, which joint is this, and what does the manual say about it?

  1. A tee joint, which forms a T in cross section
  2. An edge joint, which is not very strong
  3. A corner joint, which forms an L in cross section
  4. A lap joint, one of the strongest joint types
Show the answer

Answer: B. TM 9-237 describes the edge joint as joining two or more parallel or nearly parallel members. It is not very strong and is used on sheet-metal edges, mufflers and tanks for liquids. Corner and tee joints join members at right angles, and a lap joint overlaps one piece on the other.

Source: TM 9-237 (1976), para 3-16, Edge Joint, U.S. Army TM 9-237, Welding Theory and Application, Chapter 3: Welding Processes

Welding Preparation · 22% of the exam

Preparing job sites; setting up welding equipment; preparing materials.

3. Your shop is laying out four arc welding stations in a row along one wall. Under ANSI Z49.1:2021, Section 4.1.5, how should the stations be set up where operations permit?

  1. Finished with bright, glossy white paint on the nearby walls
  2. Separated from each other by noncombustible screens or shields
  3. Given one shared exhaust fan in the middle of the shop roof
  4. Spaced at least 35 feet apart from each other along the wall
Show the answer

Answer: B. ANSI Z49.1:2021, Section 4.1.5, says that where operations permit, welding stations are separated by noncombustible screens or shields. These protect nearby workers from arc rays and spatter. Z49.1 asks for low-reflectivity wall finishes, not glossy ones, and the 35-foot figure is a fire-hazard distance, not a station spacing. In California, 8 CCR 4851(a) also calls for noncombustible or flameproof screens.

Source: ANSI Z49.1:2021, 4.1.5 Welding Booths (with 4.1.3), ANSI Z49.1:2021, Safety in Welding, Cutting, and Allied Processes, Chapter 4 (free AWS download)

4. Your crew will MIG weld (GMAW) heavy structural fillets with ER70S-6 solid wire. Deeper joint penetration matters more than low spatter on this job. According to Hobart Brothers, which shielding gas fits this goal?

  1. Argon with 2 percent oxygen, which increases penetration
  2. An argon/CO2 blend, which increases joint penetration
  3. 100 percent CO2, which increases joint penetration
  4. 100 percent argon, which increases penetration on steel
Show the answer

Answer: C. Hobart Brothers says ER70S-6 can be run with 100 percent CO2 to increase joint penetration, or with an argon/CO2 blend to help minimize spatter. So CO2 fits a job where penetration matters most. The blend is the low-spatter choice, and pure argon is a gas for nonferrous work such as aluminum, not for short-circuit MIG on steel.

Source: Hobart Brothers, AWS ER70S-6 Solid Wires (shielding gas choice)

Welding, Brazing, and Soldering · 28% of the exam

Welding processes; welding techniques; post-welding procedures; brazing and soldering.

5. Your crew is switching its heavy structural welding from 7018 stick electrodes to flux-cored wire. According to Hobart Brothers' article on heavy structural welding, what is the primary benefit of the wire over the stick electrode?

  1. It runs on either polarity, so the machine set-up is simpler
  2. It needs no preheat, even on thick, restrained connections
  3. It is fed continuously, so there are fewer starts and stops
  4. It leaves no slag, so no cleaning is needed between passes
Show the answer

Answer: C. Hobart says the primary benefit of flux-cored wire over a stick electrode is continuous feeding: a stick welder must keep starting and stopping to change rods. That improves productivity and lowers the chance of defects from frequent starts and stops. Flux-cored wire still leaves slag, has a set polarity, and does not remove the need for preheat.

Source: Hobart Brothers, heavy structural welding article: primary benefit of flux-cored wire over stick

6. You will use an oxyacetylene torch to hardface the worn edge of a steel plow share. According to the Navy Steelworker manual, which flame is best for hardfacing?

  1. A carburizing flame, with an excess of acetylene
  2. A neutral flame, with equal oxygen and acetylene
  3. A strongly oxidizing flame, with a short, hissing cone
  4. An oxidizing flame, with a slight excess of oxygen
Show the answer

Answer: A. The Navy Steelworker manual says the carburizing flame is best for welding high-carbon steels, for hardfacing and for nonferrous alloys such as Monel. A neutral flame is correct for most metals, and the flame is always set to neutral first before it is adjusted to carburizing. An oxidizing flame makes steel foam and gives a brittle, porous weld.

Source: Navy Steelworker Vol. 1, Ch. 5, flame adjustment (carburizing flame uses)

Cutting Processes · 11% of the exam

Setting up cutting equipment; cutting techniques; finishing requirements.

7. A helper has attached the regulator to a full oxygen cylinder for a cutting job and is about to open the cylinder valve while facing the gauges. Under ANSI Z49.1:2021, Section 10.8.4.4, what is the correct way to do this?

  1. Stand right in front of the gauges, so the needles can be watched closely
  2. Turn the adjusting screw fully in first, so oxygen reaches the torch
  3. Open the valve quickly all the way, so the regulator seats at once
  4. Stand to one side of the regulator, out of line with the gauge faces
Show the answer

Answer: D. ANSI Z49.1:2021, Section 10.8.4.4, says to stand to one side of the regulator and not in front of the gauge faces when opening the cylinder valve. The same section says to back off (disengage) the adjusting screw and open the valve slightly, so the pressure needle rises slowly, before opening it all the way. Opening fast or with the screw turned in is the opposite of the rule.

Source: ANSI Z49.1:2021, 10.8.4.4 Special Procedure for Oxygen Cylinders

8. Your helper is cutting 1/4-in steel plate with a handheld plasma torch, and the sparks are falling straight down out of the cut. According to Hypertherm's handheld cutting tips, what does this tell you?

  1. Travel is too slow; speed up until sparks angle back about 15 to 20 degrees
  2. Travel is correct; sparks falling at 90 degrees give the cleanest cut with least dross
  3. Travel is too slow; raise the torch about 1/2 in higher so the arc reaches the bottom
  4. Travel is too fast; slow down until the sparks fall straight down at 90 degrees
Show the answer

Answer: A. Hypertherm says that if the sparks spray straight down, the torch is moving too slowly: the arc stays too long in one spot and leaves low-speed dross. Sparks spraying up mean the torch is moving too fast, and raising the torch is not the fix. The cleanest cut, with the least dross, comes when the sparks spray down below the plate at a 15 to 20 degree angle.

Source: Hypertherm, handheld plasma cutting tips: using the sparks to set travel speed

Safety · 22% of the exam

Job site and equipment safety; preventing fire hazards; personnel safety.

9. To slide a heavy base plate into place, a helper wants to roll it on two empty oxygen cylinders with their valves closed. Under 8 CCR 4650(q), is this allowed?

  1. Yes, if the cylinders are marked empty and kept away from the arc
  2. Yes, if the cylinders are empty and both valves are fully closed
  3. No; cylinders may not be used as rollers or supports, full or empty
  4. Yes, if the valve protection caps are screwed on both cylinders first
Show the answer

Answer: C. 8 CCR 4650(q) says cylinders shall never be used as rollers or supports, whether full or empty. Closing the valves, putting on caps or marking them empty does not change this. Use rollers, dollies or rigging made for moving loads.

Source: 8 CCR 4650(q), California Code of Regulations, Title 8, Section 4650 (Cal/OSHA): Storage, Handling, and Use of Cylinders

10. Your crew is welding steel connections on all four floors of a California building under construction. Under 8 CCR 1922(a)(1), where must at least one 2A-rated fire extinguisher be located on each floor of this multi-story building?

  1. Adjacent to the stairway on each floor level
  2. Beside the elevator or hoist on each floor level
  3. At the welding machine, on the ground floor
  4. In the site office, near the main entrance
Show the answer

Answer: A. 8 CCR 1922(a)(1) requires at least one fire extinguisher rated not less than 2A on each floor, and in multi-story buildings at least one must be located adjacent to the stairway at each floor level. An extinguisher only in the office or at ground level does not cover the upper floors where the hot work is.

Source: 8 CCR 1922(a)(1), California Code of Regulations, Title 8, Section 1922 (Cal/OSHA Construction Safety Orders): Portable Fire Extinguishers

Where to go from here

How the license works, from experience to fees: how to get a C-60 license. Everything about the course: the C-60 exam page.

Questions from our free C-60 test, written from CSLB License Examination Study Guide, Welding (C-60), form 13E-60 (03-2026), for examinations scheduled on or after April 1, 2024. CSLB notes that the percentages are approximate. Reviewed 14 October 2026. Study guidance only; we are not affiliated with CSLB or PSI.

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