Ten 456A Welder questions in the format of the Red Seal exam: four options, one correct answer, no trick questions. They are free to use, print and share. There is nothing to sign up for on this page.
01How to use these
The questions come from the TicketPrep 456A bank and are spread across the exam's work activities in the order and roughly the proportion the Red Seal Program publishes for this trade: A (performs common occupational skills), B (performs layout and fabrication of components for welding), C (performs cutting and gouging), D (performs welding processes). Answer each one before opening the explanation. Every explanation covers all four options, because on the real exam the wrong options are written to be plausible, and knowing why they are wrong is most of the skill.
- Pace. The exam allows four hours for 125 questions, so about 1 min 55 s per question. Try these at that pace.
- Print. The printed version shows the questions and the answer key without the explanations, so it works as a handout. Download PDF
- Mark. The pass mark is 70 percent on every Red Seal trade; seven of ten here is the same bar.
02The questions
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Before laying out gusset plates at a bridge-girder plant, you want to check that a combination square's blade is truly square to its stock. Which check shows this without needing another square?
- Set it on a surface plate and check with a level
- Compare it with another square from the gang box
- Scribe a line, flip the square, scribe again, compare
- Measure the blade with a tape at both ends
Show the answer
C. Correct. Hold the stock on a straight edge and scribe along the blade, then flip the square over and scribe from the same point. If the two lines coincide the square is true; if they diverge, the error is half the gap between them. Recalibrate or replace a square that is out.
Why not the others
A. A level shows whether a surface is level or plumb, not whether the blade is at 90° to the stock. Squareness is checked by the flip test or against a certified master square.
B. A comparison is only as good as the reference. Another uncalibrated shop square may be out itself, so agreement between the two proves nothing. The flip test needs no reference square.
D. A tape measures length, not the angle between blade and stock. The blade can be the right length and still be out of square.
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A welder with a full beard must be protected from manganese fume in a mine shop where local exhaust cannot fully control exposure. Which respirator arrangement suits?
- A disposable N95 pressed firmly over the beard
- A loose-fitting powered air-purifying (PAPR) helmet
- No respirator; the helmet deflects the fume plume
- A half-mask with P100 filters, fit-tested over the beard
Show the answer
B. Correct. A loose-fitting PAPR welding helmet does not rely on a face seal, so facial hair does not defeat it; the blower keeps filtered air flowing over the face. Selection, training and maintenance follow the respiratory protection program (CSA Z94.4).
Why not the others
A. A disposable respirator is also tight-fitting and cannot seal over a beard. Pressing it harder does not stop leakage at the edges.
C. A standard welding helmet does not filter air, and fume reaches the breathing zone around it. Where ventilation cannot control exposure, a respirator is required.
D. A tight-fitting half-mask cannot seal over facial hair, so it would fail a fit test. The filter rating does not help if air leaks around the seal.
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For a parallel-line saddle template on a 114.3 mm (4 in NPS) OD branch, the stretchout is divided into 16 equal spaces. How far apart are the ordinate lines? (π = 3.1416)
- 22.4 mm
- 44.9 mm
- 7.1 mm
- 11.2 mm
Show the answer
A. Correct. Stretchout = πD = 3.1416 × 114.3 = 359.08 mm; 359.08 ÷ 16 = 22.44 mm. Each ordinate then carries the length projected from the matching element line; more divisions give a smoother curve on larger pipe.
Why not the others
B. This divides the circumference into 8 spaces (359.1 ÷ 8 = 44.9 mm), not 16. With 16 element lines the spacing is 22.4 mm.
C. This is 114.3 ÷ 16: the diameter was divided instead of the circumference. The stretchout is πD = 3.1416 × 114.3 = 359.1 mm, so each space is 22.4 mm.
D. This is πr ÷ 16, using the radius where the diameter belongs (half the circumference). C = πD = 359.1 mm; 359.1 ÷ 16 = 22.4 mm.
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Factory-bevelled carbon-steel pipe for butt welding (the ASME B16.25 standard end preparation) usually arrives with what bevel angle and root face?
- 60° with a 1.6 mm (1/16 in) land
- 30° with a 3.2 mm (1/8 in) land
- 37.5° with a 1.6 mm (1/16 in) land
- 45° with no land
Show the answer
C. Correct. The standard end prep is 37.5° ±2.5° with a 1.6 mm ±0.8 mm (1/16 ± 1/32 in) root face, giving a 75° included groove when two ends meet. The WPS may call for a different prep, in which case re-bevel.
Why not the others
A. 60° is the included angle of a plate V-groove made from two 30° bevels, not a pipe-end bevel. The standard pipe end is 37.5°.
B. 30° is a common bevel on plate joints. Standard pipe ends are bevelled at 37.5° with a 1.6 mm (1/16 in) land.
D. A 45° knife-edge bevel would burn through at the root and waste filler. Pipe comes at 37.5° with a 1.6 mm land.
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On a food-plant job, the flap discs and wire brushes used on 316L stainless piping must never have been used on carbon steel. Why?
- Used discs leave too rough a sanitary finish
- Embedded iron particles rust and start pitting
- Steel residue raises the grinding temperature
- Carbon from the disc sensitizes the HAZ
Show the answer
B. Correct. Carbon-steel particles carried on a used disc or brush embed in the stainless surface, rust, and break down the passive chromium-oxide film, which leads to rust staining and pitting. Dedicated, marked stainless wheels and stainless-wire brushes prevent it.
Why not the others
A. Surface finish is set by the grit and the finishing sequence, not by what the disc was used on before. The reason for dedicated stainless consumables is iron contamination, which rusts and pits the surface.
C. Residue on a disc does not change the grinding temperature in any way that matters here. The reason for dedicated consumables is contamination: embedded iron rusts on the stainless surface and starts corrosion.
D. Sensitization is chromium-carbide precipitation caused by holding the metal at about 425–870 °C (800–1600 °F); a grinding disc does not add enough carbon to cause it. The problem with shared discs is free iron embedded in the surface.
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You need to pierce 20 mm (3/4 in) plate by hand to start an interior cut. After preheating a spot to bright red, what is the correct technique?
- Open the cutting oxygen before preheating the spot
- Hold the tip in the preheat position and open the oxygen fully
- Lower the tip onto the plate to focus the heat
- Raise the tip a little, tilt it, then open the oxygen slowly
Show the answer
D. Correct. Lifting and tilting the tip keeps molten slag from blowing back into it as the jet breaks through. Open the cutting oxygen gradually, and once through, bring the tip back to cutting height and angle and move off along the line.
Why not the others
A. Oxygen on cold steel does nothing; the metal must first be at kindling temperature. Preheat, then lift and tilt, then open the oxygen slowly.
B. Opening full oxygen at normal height with the tip straight blows molten slag straight back up into the tip. That plugs orifices and can cause a backfire.
C. A tip touching the plate overheats and backfires, and it will be plugged by slag during the pierce. Keep the inner cones just off the surface, then lift and tilt to pierce.
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What does the final digit, 8, in E4918 (E7018) tell you about the electrode's coating and current?
- Rutile iron-powder coating; flat position only
- High-cellulose sodium coating; DCEP only
- Low-hydrogen potassium with iron powder; DCEP or AC
- Rutile potassium coating; AC or DC either polarity
Show the answer
C. Correct. The 8 means a basic (lime-fluoride) low-hydrogen coating with potassium and iron powder, run on DCEP or AC. The low moisture of the coating is what keeps diffusible hydrogen down, which is why these rods live in a holding oven.
Why not the others
A. Rutile iron-powder coatings end in 4 (E4914, E4924), and the flat/horizontal limit on E4924 comes from its position digit 2, not from the last digit. The 8 is the low-hydrogen class.
B. That is a last digit of 0, as on E4310 (E6010). Cellulosic coatings produce a lot of hydrogen, which is the opposite of what the 8 identifies.
D. That is a last digit of 3, as on E4313 (E6013): a soft, easy arc for sheet and general work. The 8 identifies a basic, low-hydrogen coating.
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The WPS for 38 mm (1-1/2 in) plate calls for a 93 °C (200 °F) minimum preheat, measured 75 mm (3 in) from the joint. You have a 93 °C (200 °F) temperature-indicating stick. How do you confirm preheat?
- Mark 75 mm (3 in) from the joint; the mark melts when hot enough
- Heat until the plate shows a dull red colour, then start
- Mark the plate where the torch flame is playing
- Mark the joint face; if the mark smokes, preheat is reached
Show the answer
A. Correct. A temperature-indicating stick leaves a dry chalky mark below its rating and a liquid smear at or above it. Checking at the WPS distance (commonly 75 mm / 3 in) shows the plate has soaked through, not just the surface under the flame; a higher-rated stick can bracket an upper limit.
Why not the others
B. Steel does not glow dull red until it is well over 500 °C, far above a 93 °C preheat; that would overheat the plate and could exceed any interpass limit. Use the indicating stick at the stated location.
C. Where the flame is playing the surface reads far hotter than the plate through its thickness. Remove the heat, let it soak through, and check at 75 mm (3 in) from the joint as the WPS says.
D. The joint face is where the heat is applied and reads high, and smoking is not the test: the stick's mark has to melt. Measure at the distance the WPS gives, 75 mm (3 in) from the joint.
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At a bridge-girder field splice, the crew is welding FCAW-G with E491T-1M and 75/25 gas. Wind at the joint measures 15 km/h (9 mph). What should be done before welding?
- Double the gas flow to hold the shield
- Erect wind screens or an enclosure at the joint
- Shorten the CTWD to about 6 mm (1/4 in)
- Weld quickly in the gaps between gusts
Show the answer
B. Correct. Drafts above about 8 km/h (5 mph), the limit AWS D1.1 sets for gas-shielded processes, blow the shielding away; apply the governing code and WPS. Screens or a tent bring the wind at the arc down. The alternative is a self-shielded wire, but only under a WPS qualified for it.
Why not the others
A. Higher flow makes turbulence that draws air into the shield, and wind still strips it away. Codes set a wind limit for gas-shielded processes for this reason. Screen the joint.
C. A very short stickout causes burn-back and nozzle spatter on FCAW-G, and it does not stop a crosswind blowing the gas off. Screen the joint.
D. Gusts arrive without warning, and a single one leaves porosity. Shield protection has to be continuous, which means screening the joint.
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An aerospace subcontractor is GTAW welding a deep inside corner that needs the tungsten to extend well past the cup. Which torch component lets the tungsten extend further while keeping good shielding?
- A standard collet body with a higher flow
- A longer back cap on the torch
- A smaller cup to concentrate the gas
- A gas lens collet body and matching cup
Show the answer
D. Correct. The gas lens's fine screens straighten the argon into a smooth (laminar) column that holds together further from the cup, so the tungsten can extend about 1.5 times the cup bore instead of about one. It often allows a lower flow rate as well.
Why not the others
A. More flow through a standard collet body becomes turbulent and draws air into the shield, causing porosity. A gas lens gives a laminar column that tolerates the longer extension.
B. The back cap only houses the rear of the tungsten; a longer one lets a longer tungsten be fitted but does nothing for gas coverage at the arc. A gas lens keeps the shield intact.
C. A smaller cup narrows the gas coverage and makes the long extension worse; it helps access, not shielding. A gas lens is what keeps the shield intact over a longer extension.
03Answer key
| Question | Answer | Work activity |
|---|---|---|
| Q1 | C | Performs common occupational skills |
| Q2 | B | Performs common occupational skills |
| Q3 | A | Performs layout and fabrication of components for welding |
| Q4 | C | Performs layout and fabrication of components for welding |
| Q5 | B | Performs cutting and gouging |
| Q6 | D | Performs cutting and gouging |
| Q7 | C | Performs welding processes |
| Q8 | A | Performs welding processes |
| Q9 | B | Performs welding processes |
| Q10 | D | Performs welding processes |
04More free questions
For the 456A exam itself, the 456A exam guide covers the work activities, their weights and how the exam is scored, and the 456A Welder practice exam page describes the full TicketPrep 456A question bank. The same free format is available for the other 10 trades, plus the free guides on the pass mark, question counts, exam day and how to study.
How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.