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NCCER Boilermaker study materials
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NCCER Boilermaker practice questions

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Question 1Boilermaking Safety and Tools

What is the minimum eye protection required when operating a bench grinder?

  1. A face shield only
  2. No protection with a guard
  3. Tinted sunglasses
  4. Safety glasses Correct answer.

Explanation

Impact-rated safety glasses are the minimum eye protection for bench grinding, and a face shield may be worn over them for added protection. A machine guard controls sparks and debris but does not replace personal eye protection.

Question 2Boilermaking Safety and Tools

A personal fall arrest system must limit the free-fall distance to no more than:

  1. 15 feet
  2. 6 feet Correct answer.
  3. 10 feet
  4. 2 feet

Explanation

Fall arrest equipment must be rigged so that a worker falls no more than 6 feet before the system begins to arrest the fall. This keeps the arresting forces within the capacity of the body and the equipment.

Question 3Boilermaking Safety and Tools

What must be done first before a worker enters a permit-required confined space?

  1. Notify the client
  2. Test the atmosphere Correct answer.
  3. Ventilate for an hour
  4. Put on a harness

Explanation

Atmospheric testing for oxygen, flammables, and toxic contaminants must be performed and evaluated before entry is authorized. Ventilation or other controls follow only after the test results are known.

Question 4Boilermaking Safety and Tools

Who is authorized to remove a lockout device from an energy-isolating point?

  1. Any electrician
  2. The client
  3. Any supervisor
  4. Its installer Correct answer.

Explanation

Only the employee who applied the lock and tag may remove it, which is the core of lockout/tagout control. Removal by anyone else requires a documented exception procedure with employer verification.

Question 5Boilermaking Safety and Tools

A hot work permit is required before starting which activity?

  1. Painting
  2. Bolting flanges
  3. Hydrostatic testing
  4. Welding or cutting Correct answer.

Explanation

Welding, cutting, grinding, and other spark- or flame-producing tasks require a hot work permit issued after fire hazards are assessed. The permit confirms fire watch, extinguishers, and area preparation.

Question 6Boilermaking Safety and Tools

A cold chisel with a mushroomed head should be:

  1. Used only overhead
  2. Used with a bigger hammer
  3. Painted for visibility
  4. Ground back to shape Correct answer.

Explanation

Mushroomed heads can spall and throw metal fragments, so the head must be dressed back to a safe shape or the tool discarded. Impact tools are inspected before each use for this condition.

Question 7Boilermaking Safety and Tools

What does the ring test on a bonded abrasive wheel detect?

  1. Imbalance
  2. Cracks Correct answer.
  3. Grit size
  4. Bond grade

Explanation

A sound, clear ring indicates an intact wheel, while a dull thud suggests a crack or delamination. Cracked wheels can burst at operating speed and must never be mounted.

Question 8Boilermaking Safety and Tools

How must oxygen and fuel-gas cylinders be kept in a storage area?

  1. Beside the welding table
  2. In a closed wooden box
  3. Upright, secured, and apart Correct answer.
  4. Lying on their side

Explanation

Cylinders are stored upright and secured against tipping, with valve protection caps in place. Fuel gas and oxygen are separated by at least 20 feet or a fire wall at least 5 feet high.

Question 9Boilermaking Safety and Tools

Before each lift, a wire rope sling must be inspected for:

  1. Brand name
  2. Wire breaks Correct answer.
  3. Tag color
  4. Paint color

Explanation

Broken wires, kinks, crushing, and damaged end fittings are removal criteria for wire rope slings. Inspection must be done before use and after any event that could damage the sling.

Question 10Boilermaking Safety and Tools

If a crane operator loses sight of the signal person during a lift, the operator must:

  1. Stop the operation Correct answer.
  2. Follow the last signal given
  3. Continue at slow speed
  4. Sound the horn and proceed

Explanation

The operator must stop when signals are not clearly understood or the signal person cannot be seen. The lift resumes only after communication is re-established.

Question 11Boilermaking Safety and Tools

Before an employee wears a tight-fitting respirator, the employer must provide:

  1. Earplugs
  2. A fit test Correct answer.
  3. A dust mask
  4. A physical exam

Explanation

Tight-fitting respirators require a fit test, medical evaluation, and training before use. The fit test verifies that the facepiece seals on that individual.

Question 12Boilermaking Safety and Tools

Hearing protection must be made available and worn when noise exposure reaches or exceeds:

  1. 85 dBA TWA Correct answer.
  2. 75 dBA TWA
  3. 90 dBA TWA
  4. 80 dBA TWA

Explanation

The action level for hearing conservation and hearing protection is 85 dBA as an 8-hour time-weighted average. At that level, a hearing conservation program and protector availability are triggered.

Question 13Boilermaking Safety and Tools

A secondary container holding a transferred chemical must be:

  1. Left open
  2. In sunlight
  3. Overfilled
  4. Labeled Correct answer.

Explanation

Secondary containers must be marked with the product identity and the hazards associated with it. Labels may be reduced in content but must still communicate the hazard.

Question 14Boilermaking Safety and Tools

Portable electric tools used outdoors or in wet locations must be supplied through:

  1. Double insulation only
  2. A longer cord
  3. A wooden platform
  4. A GFCI Correct answer.

Explanation

Ground-fault circuit interrupter protection is required for cord-and-plug tools used outdoors or in wet or conductive locations. The GFCI opens the circuit when current leaks to ground.

Question 15Boilermaking Safety and Tools

A scaffold platform must be fully planked and must have:

  1. A 20-foot height limit
  2. A 6-inch width
  3. Locked wheels always
  4. Guardrails Correct answer.

Explanation

Open sides and ends of scaffold platforms must be protected with guardrail systems. Planking must be complete and the scaffold must support its intended load.

Question 16Boilermaking Safety and Tools

An extension ladder used for access must extend above the landing by at least:

  1. 2 feet
  2. 3 feet Correct answer.
  3. 6 inches
  4. 1 foot

Explanation

Extension ladders must extend at least 3 feet above the landing to provide a handhold for stepping off. The ladder should also be secured and set at the proper angle.

Question 17Boilermaking Safety and Tools

A Class B fire extinguisher is selected for use on:

  1. Live electrical
  2. Flammable liquids Correct answer.
  3. Wood and paper
  4. Combustible metals

Explanation

Class B extinguishers are rated for flammable and combustible liquid fires such as gasoline, oil, and solvents. The class letters match the fuel type being burned.

Question 18Boilermaking Safety and Tools

Combustible scrap and debris left from cutting and welding should be:

  1. Swept into aisles
  2. Left until shift end
  3. Piled by the torch
  4. Cleared regularly Correct answer.

Explanation

Combustible waste must be cleared at regular intervals so it does not accumulate near ignition sources. Accumulated debris can smolder and ignite long after work stops.

Question 19Boilermaking Safety and Tools

During a hydrostatic test of a vessel, the area around the item must be:

  1. Lit by floodlights
  2. Vented to the roof
  3. Barricaded Correct answer.
  4. Heated

Explanation

Hydrostatic testing stores large amounts of energy, and a failure can release water and fragments under pressure. The test area is barricaded and access is limited to test personnel.

Question 20Boilermaking Safety and Tools

A calibrated torque wrench must be:

  1. Stored under load
  2. Recalibrated Correct answer.
  3. Oiled each shift
  4. Used as a breaker bar

Explanation

Torque wrenches are precision instruments that must be recalibrated on a set schedule to keep their readings accurate. They are returned to the lowest setting before storage and are never used to break fasteners loose.

Question 21Boilermaking Safety and Tools

Over-rolling a tube into a tubesheet can result in:

  1. Wall thinning Correct answer.
  2. No effect at all
  3. A tighter seal
  4. Higher rating

Explanation

Excessive rolling thins and work-hardens the tube wall, which can crack the tube or damage the ligament between holes. Roller torque and expansion are controlled to a specified range.

Question 22Boilermaking Safety and Tools

Before using a chain hoist, the operator should confirm that the:

  1. Chain is greased
  2. Chain is painted
  3. Hook latch works Correct answer.
  4. Load is over rating

Explanation

A functioning hook latch keeps the load from slipping off the hook and is part of the pre-use inspection. Load capacity, chain condition, and brake function are also verified before lifting.

Question 23Boilermaking Safety and Tools

When positioning a heavy plate by hand, hands should be kept:

  1. On the sling
  2. Inside the pinch zone
  3. Clear of the pinch Correct answer.
  4. Under the load

Explanation

Hands are kept out of the path where the plate can close against another surface, because pinch points cause crushing injuries. Tag lines and bars are used so the worker does not have to hold the load.

Question 24Boilermaking Safety and Tools

What is the most effective fume control when welding inside a confined space?

  1. Local exhaust Correct answer.
  2. A far-end fan
  3. Faster welding
  4. A paper dust mask

Explanation

Local exhaust ventilation captures fume at the arc before it reaches the breathing zone. Dilution fans alone may spread contaminants without removing them and can disturb shielding gas.

Question 25Boilermaking Safety and Tools

Why must a rigger know the load weight before making a lift?

  1. To fuel the crane
  2. To set the boom pin
  3. To log the time
  4. To size the rigging Correct answer.

Explanation

Sling capacity, shackle size, and the crane's rated capacity at the required radius all depend on the load weight. Lifting an unknown load risks overloading the rigging or the machine.

Question 26Boilermaking Safety and Tools

A hard hat that has absorbed a heavy impact from a falling bolt should be:

  1. kept in use until the end of the shift
  2. cleaned and stamped with the date of the impact
  3. replaced with a new hard hat Correct answer.
  4. returned to service after a visual check of the shell

Explanation

A hard hat is designed to absorb one impact by deforming or shedding energy, and that protection cannot be restored. Even when damage is not visible, the shell may have lost strength, so the hat is taken out of service and destroyed.

Question 27Boilermaking Safety and Tools

An employee wears a full face shield while grinding. What eye protection is also required underneath the shield?

  1. Sunglasses to reduce the glare
  2. Safety glasses with side shields Correct answer.
  3. No other eye protection, because the shield covers the whole face
  4. A welding helmet with a filter lens

Explanation

A face shield is secondary protection that stops large particles but does not seal against fine debris or flying chips entering from the edges. Primary eye protection such as safety glasses with side shields must be worn under the shield.

Question 28Boilermaking Safety and Tools

A pipe wrench should be operated so that the force is applied:

  1. by pulling the handle toward the body Correct answer.
  2. with both feet braced on the pipe being turned
  3. by pushing the handle away from the body
  4. by striking the handle with a hammer

Explanation

Pulling the handle lets the operator lean back and control the load with body weight, and if the wrench slips the user moves away from the work. Pushing puts the operator's face and knuckles close to the pipe and into the path of a sudden slip.

Question 29Boilermaking Safety and Tools

Why is slipping a length of pipe over a wrench handle to gain leverage considered unsafe?

  1. The pipe can slip and the handle can break Correct answer.
  2. The jaw teeth will lose their hardness
  3. The wrench will no longer fit in its tool pouch
  4. The added weight makes the tool harder to carry

Explanation

Wrenches are rated for the force applied at the handle as made; a cheater bar multiplies torque beyond that rating. The handle can snap or the pipe can slide off, and the sudden release of force throws the user off balance.

Question 30Boilermaking Safety and Tools

Oxygen cylinder valves, regulators, and fittings must be kept free of:

  1. oil and grease Correct answer.
  2. water
  3. metal chips
  4. compressed air

Explanation

Oxygen supports combustion so vigorously that a small amount of oil or grease on a fitting can ignite and burn violently when the valve is opened. Handled parts are kept clean and never lubricated with oil-based products.

Question 31Boilermaking Safety and Tools

On a bench grinder, the tool rest should be adjusted so the gap to the wheel face is no more than:

  1. 1/4 inch
  2. 1 inch
  3. 1/2 inch
  4. 1/8 inch Correct answer.

Explanation

The work rest is kept close so a workpiece cannot be pulled down into the opening between the rest and the wheel. The standard maximum clearance is 1/8 inch, with the rest readjusted as the wheel wears down.

Question 32Boilermaking Safety and Tools

A flashback arrestor is installed on an oxyfuel torch set to:

  1. raise the flame temperature for cutting
  2. stop a flame from traveling back up the hose Correct answer.
  3. hold the working pressure steady at the tip
  4. filter soot out of the fuel gas

Explanation

A flashback arrestor contains a flame path, check valve, or sintered element that quenches a flame moving backward through the line. This protects the hose, regulator, and cylinder from a flashback that could cause a rupture or explosion.

Question 33Boilermaking Safety and Tools

After locking out and tagging out a pump, the boilermaker must still:

  1. attempt a start to verify zero energy Correct answer.
  2. notify the plant owner in writing
  3. post a guard at the disconnect switch
  4. remove the tag during the repair work

Explanation

Lockout and tagout isolate the energy source, but stored energy or a misidentified disconnect can still leave the equipment live. Operating the start control after locking out confirms the correct device was isolated and that no energy remains.

Question 34Boilermaking Safety and Tools

During operation of a hydraulic torque wrench, the operator's hands must be kept:

  1. on the reaction arm to steady it
  2. on the hose fittings to check for leaks
  3. under the socket to support its weight
  4. clear of the reaction arm and pinch points Correct answer.

Explanation

The reaction arm swings with great force as the tool loads and unloads, and anything in its path is crushed. Hands and fingers are kept outside the reaction zone, and hoses are never handled while the tool is pressurized.

Question 35Boilermaking Safety and Tools

Personal fall arrest systems must be anchored to a point that can support at least:

  1. 2,500 pounds per worker
  2. 5,000 pounds per worker Correct answer.
  3. 10,000 pounds per worker
  4. 1,000 pounds per worker

Explanation

Anchorage strength is set at 5,000 pounds per attached employee unless a qualified person certifies a engineered system with a safety factor of at least two. The high value accounts for the dynamic force generated when a fall is arrested.

Question 36Boilermaking Safety and Tools

A screwdriver should never be struck with a hammer because:

  1. the handle will absorb the impact and loosen
  2. the blade can shatter and throw metal fragments Correct answer.
  3. the handle will mar the surface being worked
  4. the tip will magnetize and lose its temper

Explanation

Screwdriver blades are hardened steel and are not designed for impact; struck on the end, the tip or shank can break off and fly. A chisel or punch made for striking is used instead.

Question 37Boilermaking Safety and Tools

Which practice is acceptable when rigging a load with a crane?

  1. Guiding the load with a tag line from a safe distance Correct answer.
  2. Standing under the load to steady it by hand
  3. Riding the hook to guide the load into place
  4. Guiding the load by grabbing the sling legs

Explanation

A tag line lets the rigger control rotation and swing while staying outside the fall zone of the load. Personnel are never hoisted on the hook and never place themselves beneath or against a suspended load.

Question 38Boilermaking Safety and Tools

Acetylene gas must never be used at a pressure above:

  1. 30 psig
  2. 15 psig Correct answer.
  3. 50 psig
  4. 5 psig

Explanation

Acetylene becomes unstable and can decompose violently above about 15 psi, so regulators for acetylene service are limited to that outlet pressure. Higher delivery pressures are never used even if the torch seems to need more gas.

Question 39Boilermaking Safety and Tools

When testing the atmosphere of a confined space before entry, the correct order is to test for:

  1. toxic gas, then oxygen, then flammable gas
  2. flammable gas, then oxygen, then toxic gas
  3. flammable gas, then toxic gas, then oxygen
  4. oxygen, then flammable gas, then toxic gas Correct answer.

Explanation

Oxygen is tested first because both oxygen deficiency and enrichment are immediately life-threatening and because combustible gas meters read accurately only when oxygen is in a normal range. Flammable gas is checked next, then toxic contaminants.

Question 40Boilermaking Safety and Tools

A 2,000 lb load is lifted with a two-leg bridle sling, each leg making a 30-degree angle with the horizontal. What is the approximate tension in each leg?

  1. 1,000 lb
  2. 4,000 lb
  3. 1,155 lb
  4. 2,000 lb Correct answer.

Explanation

Each leg carries half the vertical load, which is 1,000 lb, and the leg tension equals that vertical share divided by the sine of 30 degrees, which is 0.5. The tension is therefore 1,000 divided by 0.5, or 2,000 lb per leg.

Question 41Oxyfuel Cutting, Welding, and Cutting Practices

What is the maximum allowable free acetylene pressure in a hose, torch, or regulator?

  1. 5 psig
  2. 50 psig
  3. 15 psig Correct answer.
  4. 30 psig

Explanation

Acetylene becomes unstable and can decompose explosively at pressures above about 15 psig, so free acetylene is never delivered at a higher pressure anywhere downstream of the cylinder.

Question 42Oxyfuel Cutting, Welding, and Cutting Practices

In the standard US hose color code, an oxygen hose is:

  1. Red
  2. Blue
  3. Green Correct answer.
  4. Black

Explanation

Oxygen hoses are green, fuel gas hoses are red, and inert gas hoses are black, which allows the gas service to be identified at a glance.

Question 43Oxyfuel Cutting, Welding, and Cutting Practices

Why does an acetylene cylinder contain acetone and a porous filler material?

  1. To filter out impurities as the gas leaves
  2. To keep the gas from freezing in cold weather
  3. To store acetylene safely at higher pressure Correct answer.
  4. To raise the cylinder burst pressure rating

Explanation

Acetylene is dissolved in acetone held inside a porous mass, which allows a large volume of gas to be stored at a safe pressure and helps stop a decomposition from spreading through the cylinder.

Question 44Oxyfuel Cutting, Welding, and Cutting Practices

What is the purpose of a flashback arrestor on an oxyfuel torch or regulator?

  1. Prevents reverse flow of gas in the line
  2. Filters soot out of the fuel gas
  3. Regulates delivery pressure to the torch
  4. Stops a flame from traveling back into the hose Correct answer.

Explanation

A flashback arrestor contains a quenching element that cools and extinguishes a flame front before it can reach the hose, regulator, or cylinder.

Question 45Oxyfuel Cutting, Welding, and Cutting Practices

When lighting an oxyfuel cutting torch, which valve is opened first?

  1. Fuel gas valve Correct answer.
  2. Preheat oxygen valve
  3. Both oxygen valves together
  4. Cutting oxygen lever

Explanation

The fuel gas is cracked open and lit first; preheat oxygen is added afterward to shape the flame, so the torch is never lit with oxygen already flowing at the tip.

Question 46Oxyfuel Cutting, Welding, and Cutting Practices

Which eye protection is required when operating an oxyfuel cutting torch?

  1. Filtered goggles of the proper shade Correct answer.
  2. Clear safety glasses only
  3. A clear face shield
  4. A welding helmet with a shade 10 lens

Explanation

Filtered goggles in the shade suited to the work protect the eyes from ultraviolet and infrared radiation, sparks, and hot slag while still allowing the cut line to be seen.

Question 47Oxyfuel Cutting, Welding, and Cutting Practices

Compared with cutting 1/4 in. plate, cutting 1 in. plate requires a cutting tip with:

  1. Smaller orifices and lower flow
  2. Larger orifices and higher flow Correct answer.
  3. The same size with more pressure
  4. A shorter, narrower tip head

Explanation

Thicker plate needs more preheat and a much larger volume of cutting oxygen, so the tip orifices must be larger and the cutting oxygen flow higher.

Question 48Oxyfuel Cutting, Welding, and Cutting Practices

Why must oxygen regulators and fittings be kept completely free of oil and grease?

  1. It changes the color of the flame
  2. It shortens the life of the hose
  3. It hardens the regulator seat
  4. Oxygen can ignite oil or grease Correct answer.

Explanation

Oxygen under pressure combines with hydrocarbon oils and greases and can ignite or detonate on contact, so oxygen equipment is handled with clean, oil-free hands and tools.

Question 49Oxyfuel Cutting, Welding, and Cutting Practices

A backfire is best described as:

  1. A fuel gas leak at a regulator connection
  2. A momentary pop or flash at the tip that may go out Correct answer.
  3. A flame that travels back through the torch into the hose
  4. A steady flame burning on the outside of the tip

Explanation

A backfire is a momentary pop or flash at the tip after which the flame may reignite or go out, while a flashback travels back through the torch and hoses and is far more serious.

Question 50Oxyfuel Cutting, Welding, and Cutting Practices

Which condition most often produces a backfire at the torch tip?

  1. Opening the fuel valve too slowly when lighting
  2. Loose or overheated tip, or spatter in the orifices Correct answer.
  3. Turning the oxygen cylinder valve on too quickly
  4. Using a longer length of hose than normal

Explanation

Spatter blocking the orifices, a loose tip, or an overheated tip disturbs gas flow at the tip and lets the flame pop back momentarily.