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SOLAS Metal Fabrication study materials
SOLAS Metal Fabrication study resources

SOLAS Metal Fabrication practice questions

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Question 1Metal Fabrication (craft apprenticeship programme)

In a metal fabrication workshop, a guillotine shear is primarily used to perform which operation on sheet metal?

  1. Folding a sharp 90-degree bend along an edge
  2. Punching a round hole through the sheet
  3. Rolling the sheet into a cylinder
  4. Cutting a straight line across a flat sheet Correct answer.

Explanation

A guillotine shear holds the sheet against a bed and drives a straight blade down to sever it along a straight line. Rolling, hole punching and folding are done by different machines, so only the straight-line cut matches the tool.

Question 2Metal Fabrication (craft apprenticeship programme)

Which filler metal and process combination is standard for joining mild steel using the gas tungsten arc welding (TIG) process?

  1. ER70S-2 filler rod with direct current electrode negative Correct answer.
  2. Aluminium-silicon rod with alternating current
  3. Silicon-bronze rod with direct current electrode positive
  4. Bare copper-coated steel wire with direct current electrode positive

Explanation

Mild steel is TIG welded with a matching low-carbon steel rod such as ER70S-2, and the electrode is kept negative so most heat goes into the work while the tungsten stays cool. Copper-coated wire belongs to MIG, and the other fillers suit aluminium or bronze work.

Question 3Metal Fabrication (craft apprenticeship programme)

A fabricator needs to cut a 6 mm thick stainless steel plate with a clean edge and minimal heat distortion. Which process is best suited?

  1. Plasma arc cutting
  2. Oxy-acetylene flame cutting
  3. Tin snips
  4. Abrasive waterjet cutting Correct answer.

Explanation

Abrasive waterjet cuts thick stainless steel without a heat-affected zone, so distortion and metallurgical change are minimal. Oxy-fuel cannot cut stainless effectively, plasma leaves a heat-affected edge, and snips cannot handle 6 mm plate.

Question 4Metal Fabrication (craft apprenticeship programme)

What is the main purpose of using a vee-block when drilling a round shaft on a drill press?

  1. To measure the shaft diameter accurately
  2. To cool the drill bit with coolant
  3. To increase the spindle speed for small drills
  4. To hold the shaft securely and prevent it rotating during drilling Correct answer.

Explanation

A vee-block cradles a cylindrical workpiece and, when clamped, stops it spinning as the drill bites. Speed, cooling and measurement are handled by other means, so only workholding explains its use.

Question 5Metal Fabrication (craft apprenticeship programme)

A welder is preparing a butt joint in 10 mm mild steel plate for full penetration. Which joint preparation is most appropriate?

  1. Single-vee groove with a root gap and root face Correct answer.
  2. Single-bevel groove with zero root face
  3. Flange joint with the edges turned up
  4. Square edge with no gap

Explanation

Full penetration in 10 mm plate requires a groove preparation that lets the arc reach the root, so a single-vee with a root gap and a small root face is used. A square edge cannot be fully penetrated at that thickness, and the other options do not provide adequate access.

Question 6Metal Fabrication (craft apprenticeship programme)

Which safety precaution is essential before arc welding in a confined space such as a tank interior?

  1. Relying on the tank's natural ventilation alone
  2. Removing the welding helmet to improve visibility
  3. Continuous forced ventilation and a standby person outside Correct answer.
  4. Welding at maximum current to finish quickly

Explanation

Confined-space welding generates shielding gas, fumes and possible oxygen deficiency, so continuous forced ventilation and an attendant outside are required. Natural ventilation is unreliable, and speed or removing PPE increases risk rather than controlling it.

Question 7Metal Fabrication (craft apprenticeship programme)

What does the term 'kerf' refer to when cutting metal with a saw or abrasive disc?

  1. The width of material removed by the cut Correct answer.
  2. The surface finish left on the cut edge
  3. The angle of the saw blade teeth
  4. The clamping force applied to the workpiece

Explanation

Kerf is the slot or width of material destroyed by the cutting tool, and it must be allowed for when marking out. Tooth angle, clamping and finish are separate considerations.

Question 8Metal Fabrication (craft apprenticeship programme)

A fabricator must bend 3 mm mild steel sheet to 90 degrees on a press brake. Which parameter most directly controls the inside bend radius?

  1. The vee-die opening width Correct answer.
  2. The speed of the ram descent
  3. The press tonnage rating
  4. The length of the sheet

Explanation

On air bending the inside radius is governed mainly by the vee-die opening, roughly a fraction of the die width for mild steel. Tonnage, ram speed and sheet length affect force and cycle time but not the resulting radius in the same direct way.

Question 9Metal Fabrication (craft apprenticeship programme)

Which type of weld defect appears as a elongated void running along the root of a fillet weld and is often caused by insufficient shielding gas or contamination?

  1. Porosity Correct answer.
  2. Slag inclusion
  3. Lack of fusion
  4. Underbead cracking

Explanation

Porosity is gas trapped in the solidifying weld, forming voids, and is commonly caused by poor shielding or contamination. Slag inclusion, lack of fusion and cracking have different causes and appearances.

Question 10Metal Fabrication (craft apprenticeship programme)

When marking out a steel plate, why is a centre punch used before drilling?

  1. To harden the surface around the hole
  2. To remove burrs from the previous cut
  3. To enlarge the hole to final size
  4. To create a small indentation that guides the drill and prevents wandering Correct answer.

Explanation

A centre punch produces a conical dimple that locates the drill point so it starts accurately instead of skidding. It does not size, harden or deburr the hole.

Question 11Metal Fabrication (craft apprenticeship programme)

A welder notices a concave, undersized fillet weld with legs shorter than specified. Which term best describes this condition?

  1. Insufficient throat Correct answer.
  2. Excessive convexity
  3. Overlap
  4. Undercut

Explanation

When the fillet legs are shorter than the drawing size, the throat is too small and the weld is described as insufficient throat, a strength-reducing defect. Convexity, undercut and overlap describe different profile faults.

Question 12Metal Fabrication (craft apprenticeship programme)

Which abrasive is most commonly used on a grinding wheel for general carbon steel fabrication because of its toughness and low cost?

  1. Silicon carbide
  2. Cubic boron nitride
  3. Diamond
  4. Aluminium oxide Correct answer.

Explanation

Aluminium oxide grit is tough and economical, making it the standard choice for carbon steel grinding. Silicon carbide suits non-ferrous and cast iron, while diamond and CBN are reserved for hard or exotic materials.

Question 13Metal Fabrication (craft apprenticeship programme)

A fabrication drawing specifies a weld symbol with a triangle on the arrow side and a dimension of 6 above the reference line. What does this indicate?

  1. A 6 mm spot weld at 6 mm pitch
  2. A 6 mm fillet weld on the arrow side Correct answer.
  3. A 6 mm groove weld on the other side
  4. A 6 mm butt weld with full penetration

Explanation

On a fillet weld symbol the triangle sits on the reference line, and a dimension above the line applies to the arrow side. Groove, butt and spot welds use different symbols.

Question 14Metal Fabrication (craft apprenticeship programme)

What is the primary reason for preheating thick carbon steel sections before welding?

  1. To increase the welding current available
  2. To make the weld pool more fluid for vertical welding
  3. To reduce the amount of filler metal required
  4. To slow the cooling rate and reduce the risk of hydrogen cracking Correct answer.

Explanation

Preheat slows cooling after welding, which limits the formation of hard martensite in the heat-affected zone and allows hydrogen to escape, reducing cracking risk. It does not change current, fluidity in the way described, or filler consumption.

Question 15Metal Fabrication (craft apprenticeship programme)

Which non-destructive test is best for detecting surface-breaking cracks in a ferromagnetic steel weld?

  1. Ultrasonic testing
  2. Dye penetrant inspection
  3. Magnetic particle inspection Correct answer.
  4. Radiographic testing

Explanation

Magnetic particle inspection magnetises the part and attracts particles to flux leakage at surface and near-surface discontinuities, making it well suited to ferromagnetic steel. Radiography and ultrasonics are primarily for internal flaws, and dye penetrant works on any material but is not magnetic.

Question 16Metal Fabrication (craft apprenticeship programme)

In a fabrication context, what does the abbreviation 'HAZ' stand for?

  1. Hot Annealing Zone
  2. Hardened Alloy Zone
  3. Heat-Affected Zone Correct answer.
  4. High-Alloy Zone

Explanation

The heat-affected zone is the region of parent metal whose microstructure is altered by welding heat without melting. The other expansions are not standard welding terminology.

Question 17Metal Fabrication (craft apprenticeship programme)

A fabricator is assembling a square frame from 40 x 40 mm square hollow section. Which method gives the most reliable squareness before welding?

  1. Tack welding one corner, then measuring the diagonals
  2. Welding all corners fully and then bending to square
  3. Relying on the saw cut angles alone
  4. Clamping the frame on a flat table, checking both diagonals are equal, then tacking Correct answer.

Explanation

Equal diagonals on a flat surface confirm the frame is square, and tacking while clamped preserves that geometry. Welding before checking, bending after welding, or trusting cut angles alone all allow distortion to go uncorrected.

Question 18Metal Fabrication (craft apprenticeship programme)

What is the effect of increasing the travel speed of an arc too much during manual metal arc welding?

  1. A narrower, thinner bead with a risk of lack of fusion Correct answer.
  2. No change to the weld profile
  3. Increased deposition and a flatter bead
  4. Deeper penetration and a wider bead

Explanation

Excessive travel speed reduces heat input per unit length, producing a narrow, thin bead and increasing the risk of lack of fusion or undercut. Penetration and width decrease rather than increase.

Question 19Metal Fabrication (craft apprenticeship programme)

Which type of steel is most likely to require low-hydrogen electrodes and strict storage control?

  1. Galvanised sheet
  2. Mild steel sheet
  3. High-strength low-alloy structural steel Correct answer.
  4. Cast iron

Explanation

High-strength low-alloy steels are susceptible to hydrogen-assisted cracking, so low-hydrogen consumables and controlled storage are needed. Mild steel is more forgiving, galvanised sheet raises fume concerns, and cast iron uses different consumables entirely.

Question 20Metal Fabrication (craft apprenticeship programme)

A jig is being designed to hold a small bracket for repeated drilling. Which feature is most important for consistent hole location?

  1. A quick-release pin in the base
  2. A large clamping lever for high force
  3. A painted surface for visibility
  4. A hardened drill bush positioned over the hole site Correct answer.

Explanation

A hardened drill bush guides the drill precisely, controlling position and reducing wander across parts. Clamping force, paint and quick-release pins help handling but do not locate the hole.

Question 21Metal Fabrication (craft apprenticeship programme)

What is the main reason for using a backing bar or ceramic backing tape when welding a root pass?

  1. To add alloying elements to the weld
  2. To cool the weld rapidly
  3. To support the molten root and prevent burn-through or excessive penetration Correct answer.
  4. To increase the welding current

Explanation

Backing supports the root pool so it does not collapse or burn through, giving a consistent root profile. It does not raise current, cool the weld or intentionally alloy it.

Question 22Metal Fabrication (craft apprenticeship programme)

A 2 m long steel beam is welded along one flange only, causing it to bow. Which technique best reduces this distortion?

  1. Increasing the weld size to compensate
  2. Welding continuously from one end to the other at high current
  3. Cooling the flange with water immediately after welding
  4. Balancing the welds by alternating sides and using backstep or staggered sequences Correct answer.

Explanation

Balancing heat input on opposite sides and using backstep or staggered sequences distributes shrinkage and limits bowing. Continuous high-current welding and larger welds increase distortion, and rapid water cooling can cause cracking.

Question 23Metal Fabrication (craft apprenticeship programme)

Which tool is used to check that two adjacent surfaces of a fabricated frame are at exactly 90 degrees?

  1. Feeler gauge
  2. Radius gauge
  3. Engineer's square Correct answer.
  4. Vernier caliper

Explanation

An engineer's square has a fixed 90-degree reference and is used to check squareness of corners. Calipers measure distance, feeler gauges measure gaps, and radius gauges check fillet sizes.

Question 24Metal Fabrication (craft apprenticeship programme)

Why is it important to remove mill scale from the joint faces before welding structural steel?

  1. Mill scale can cause lack of fusion and porosity by interfering with the arc and shielding Correct answer.
  2. Mill scale makes the steel magnetic
  3. Mill scale increases the weld metal strength
  4. Mill scale lowers the melting point of the steel

Explanation

Mill scale is an oxide layer that can prevent proper arc initiation and fusion and can trap gas, producing defects. It does not lower melting point, create magnetism or improve strength.

Question 25Metal Fabrication (craft apprenticeship programme)

A fabricator must produce a series of identical 90-degree brackets from 5 mm plate with a 50 mm leg. Which manufacturing approach gives the best repeatability?

  1. Laser cut or CNC punch the blanks from a nesting program, then bend on a press brake with a stop Correct answer.
  2. Bend first, then trim the legs to length
  3. Cut oversize and grind each leg to 50 mm by eye
  4. Mark each bracket individually and cut with a hand hacksaw

Explanation

CNC cutting from a nesting program produces identical blanks, and a press brake backstop repeats the bend position, giving consistent legs. Hand marking, grinding by eye and bending before trimming all introduce variation.

Question 26Metal Fabrication (craft apprenticeship programme)

When oxy-acetylene cutting a 20 mm mild steel plate, which parameter mainly determines the width of the cut kerf?

  1. The temperature of the preheat flame
  2. The cutting tip orifice size Correct answer.
  3. The length of the cutting torch body
  4. The pressure in the oxygen cylinder

Explanation

The kerf width is set by the size of the cutting oxygen orifice in the tip; a larger orifice gives a wider kerf and allows thicker plate to be cut. Tip size must be matched to plate thickness. Cylinder pressure and torch length do not define kerf width.

Question 27Metal Fabrication (craft apprenticeship programme)

Which filler metal designation would a fabricator select for gas metal arc welding of 5083 aluminium plate?

  1. ER5356 Correct answer.
  2. ER80S-D2
  3. ER70S-6
  4. ER308L

Explanation

ER5356 is an aluminium-magnesium filler suited to 5xxx base metals such as 5083 and gives good strength and crack resistance. The other designations are carbon steel or stainless steel fillers and are not compatible with aluminium.

Question 28Metal Fabrication (craft apprenticeship programme)

A fabricator is drilling a 10 mm hole in 6 mm mild steel plate on a pedestal drill. Which action best prevents the drill grabbing and spinning the workpiece?

  1. Applying cutting fluid continuously
  2. Using a longer series drill bit
  3. Reducing the spindle speed to the minimum
  4. Clamping the plate to the drill table Correct answer.

Explanation

Clamping the workpiece removes the risk of the bit grabbing and rotating the plate, which is a common cause of hand injury on pedestal drills. Speed, coolant and bit length affect hole quality but not workpiece security.

Question 29Metal Fabrication (craft apprenticeship programme)

In a fabrication workshop, which document defines the sequence of welded joints, welding process and inspection requirements for a pressure-retaining structure?

  1. The general arrangement drawing
  2. The welding procedure specification Correct answer.
  3. The material test certificate
  4. The cutting list

Explanation

A welding procedure specification (WPS) records the qualified process, joint details, consumables and parameters, and is supported by procedure qualification records. Material certificates and drawings give material and geometry data but not the qualified welding variables.

Question 30Metal Fabrication (craft apprenticeship programme)

Why is a magnetic drill press preferred over a hand-held electric drill for enlarging holes in a structural steel column on site?

  1. It can drill through concrete as well as steel
  2. The magnetic base holds the drill firmly to the steel surface Correct answer.
  3. It uses a higher voltage supply than hand drills
  4. It removes the need for a cutting lubricant

Explanation

The electromagnetic base clamps the drill to the ferrous workpiece, giving rigid alignment and controlled feed for accurate, safe hole enlargement. It does not change supply voltage, remove lubricant needs, or suit masonry.

Question 31Metal Fabrication (craft apprenticeship programme)

Which feature of a fabricated steel guardrail assembly is checked with a feeler gauge and straight edge after welding?

  1. Hardness of the heat-affected zone
  2. Straightness of the rail along its length Correct answer.
  3. Thickness of the paint coating
  4. Depth of weld penetration at the root

Explanation

A straight edge laid along the member shows any bow or kink, and a feeler gauge quantifies the gap, giving a measurable straightness check after welding distortion. Penetration, hardness and coating thickness need other methods.

Question 32Metal Fabrication (craft apprenticeship programme)

What is the purpose of a run-off tab when welding a full-penetration butt joint in a plate girder?

  1. To measure the interpass temperature
  2. To preheat the joint locally before welding
  3. To allow the arc to start and finish beyond the joint so the ends are sound Correct answer.
  4. To shield the weld from draughts

Explanation

Run-off and run-on tabs extend the weld beyond the joint edges so crater defects and start-stop imperfections fall outside the finished component. They do not preheat, measure temperature or provide shielding.

Question 33Metal Fabrication (craft apprenticeship programme)

A fabricator must cut a 45-degree chamfer on the edge of a 12 mm steel plate for a single-V butt weld. Which method gives the most consistent bevel along the full length?

  1. Freehand oxy-acetylene cutting
  2. Thermal cutting with a guided track or bevelling machine Correct answer.
  3. Hand filing after a square cut
  4. Abrasive chop saw cuts at an angle

Explanation

A guided track or mechanical bevelling machine controls the torch angle and speed, producing a uniform bevel and smooth face suitable for welding. Freehand cutting and filing give variable angles and roughness.

Question 34Metal Fabrication (craft apprenticeship programme)

Which condition most commonly causes porosity in a flux-cored arc weld made outdoors?

  1. A copper-coated contact tip
  2. Too slow a travel speed
  3. Excessive interpass temperature
  4. Wind disrupting the gas shield Correct answer.

Explanation

Wind can blow away the shielding gas on gas-shielded FCAW, allowing nitrogen and oxygen from the air into the weld pool and forming porosity. Interpass temperature, travel speed and contact tip material affect other aspects but not shielding directly.

Question 35Metal Fabrication (craft apprenticeship programme)

What does the term 'camber' describe when inspecting a fabricated steel beam?

  1. A curvature built into or induced along the length of the beam Correct answer.
  2. A twist about the longitudinal axis
  3. A local dent in the web
  4. A deviation of the flange from square

Explanation

Camber is the longitudinal curvature of a beam, either specified in the design or induced by welding. Twist, flange squareness and local dents are separate geometric features checked against different tolerances.

Question 36Metal Fabrication (craft apprenticeship programme)

Which personal protective measure is essential when grinding a weld with an angle grinder in a fabrication bay?

  1. A face shield worn over safety glasses Correct answer.
  2. An apron without eye protection
  3. Leather gloves only
  4. Ear defenders alone

Explanation

Grinding throws high-speed abrasive particles and metal fragments, so a face shield over safety glasses protects the eyes and face. Gloves, aprons and hearing protection are useful but do not replace eye and face protection.

Question 37Metal Fabrication (craft apprenticeship programme)

A fabricator needs to produce a true 90-degree corner between two plates before tack welding. Which tool is most appropriate to confirm the angle?

  1. A radius gauge
  2. A vernier caliper
  3. An engineer's try square Correct answer.
  4. A feeler gauge

Explanation

A try square has a fixed 90-degree reference and is used to check squareness of corners and joints before tacking. Calipers measure linear dimensions, feeler gauges measure gaps, and radius gauges check fillet radii.

Question 38Metal Fabrication (craft apprenticeship programme)

What is the main effect of using a short arc length when welding with a covered electrode?

  1. Increased spatter and arc blow
  2. Reduced deposition rate and shallow penetration
  3. Improved shielding and deeper penetration Correct answer.
  4. Higher risk of slag inclusions

Explanation

A short arc keeps the shielding gas envelope tight around the molten pool, giving good protection and better penetration. Too long an arc increases spatter, loses shielding and reduces penetration.

Question 39Metal Fabrication (craft apprenticeship programme)

Which type of steel section is produced by folding a flat strip through a series of rolls to form a hollow rectangular shape?

  1. Hot-rolled angle
  2. Cold-formed square hollow section Correct answer.
  3. Parallel flange channel
  4. Universal beam

Explanation

Cold-formed square hollow sections are made by roll-forming strip and welding the longitudinal seam, giving thin walls and tight corner radii. Universal beams, channels and angles are hot-rolled profiles with different cross-sections.

Question 40Metal Fabrication (craft apprenticeship programme)

A fabricator is welding a 25 mm thick carbon steel bracket and notices the weld pool is sluggish and penetration is poor. Which action is most appropriate?

  1. Apply preheat to the joint before welding Correct answer.
  2. Increase travel speed significantly
  3. Reduce the welding current
  4. Use a smaller electrode diameter

Explanation

Thick sections conduct heat away rapidly, so preheat slows the cooling rate, improves fusion and reduces the risk of hard, crack-prone heat-affected zones. Increasing travel speed or reducing current would worsen penetration.

Question 41Metal Fabrication (craft apprenticeship programme)

Which method is used to straighten a distorted fabricated steel frame after welding?

  1. Adding stiffener plates at random locations
  2. Quenching the whole frame in water
  3. Localised heating with a torch followed by controlled cooling Correct answer.
  4. Increasing the weld size on the convex side

Explanation

Localised heating creates controlled shrinkage that pulls the distorted area back into line; this is the basis of flame straightening. Quenching can harden and crack the steel, and adding weld or random stiffeners worsens distortion.

Question 42Metal Fabrication (craft apprenticeship programme)

In a fabricated steel assembly, what is the purpose of a gusset plate?

  1. To provide a lifting point for the assembly
  2. To protect the joint from corrosion
  3. To transfer load between members at a joint Correct answer.
  4. To act as a temporary spacer during welding

Explanation

Gusset plates are triangular or rectangular plates welded or bolted into a corner to stiffen the joint and distribute forces between connected members. Lifting points, spacers and corrosion protection are separate functions.

Question 43Metal Fabrication (craft apprenticeship programme)

Which defect is indicated when a fillet weld shows a smooth, concave profile with legs shorter than the specified size?

  1. Spatter
  2. Underfill Correct answer.
  3. Overlap
  4. Undercut

Explanation

Underfill describes a fillet weld whose throat or leg size is below specification, often with a concave profile. Undercut is a groove melted into the base metal, overlap is weld metal spilling onto the surface without fusion, and spatter is scattered droplets.

Question 44Metal Fabrication (craft apprenticeship programme)

Which non-destructive method is used to detect internal planar defects such as lack of fusion in a thick butt weld?

  1. Ultrasonic testing Correct answer.
  2. Magnetic particle testing
  3. Dye penetrant testing
  4. Visual inspection

Explanation

Ultrasonic testing transmits high-frequency sound through the weld and detects internal reflectors such as lack of fusion and cracks in thick sections. Penetrant, magnetic particle and visual methods are limited to surface or near-surface defects.

Question 45Metal Fabrication (craft apprenticeship programme)

A fabricator is setting up a jig for repetitive welding of identical brackets. Which feature best controls distortion between parts?

  1. Clamping the parts in a fixed position with adequate restraint Correct answer.
  2. Increasing the welding current for each part
  3. Removing clamps immediately after the arc stops
  4. Using the same jig for different bracket sizes

Explanation

Clamping parts in a fixed, restrained position holds them in alignment while the weld cools, limiting movement and giving repeatable parts. Higher current increases heat input and distortion, and removing clamps too early allows movement.

Question 46Metal Fabrication (craft apprenticeship programme)

What does the abbreviation 'PPE' require a fabricator to wear when handling abrasive cut-off wheels?

  1. Safety boots only
  2. A hard hat only
  3. Eye protection, hearing protection and gloves Correct answer.
  4. A dust mask only

Explanation

Abrasive cutting generates sparks, noise and sharp fragments, so eye and hearing protection plus suitable gloves are required. A single item of PPE does not control the combined hazards of the operation.

Question 47Metal Fabrication (craft apprenticeship programme)

Which factor most influences the choice between a bolted and a welded connection in a steel fabrication?

  1. The ambient temperature on the day of assembly
  2. The colour of the final protective coating
  3. The length of the member being joined
  4. Whether the connection must be demountable or is permanent Correct answer.

Explanation

Bolted connections are chosen where dismantling, site assembly or adjustment is needed, while welded connections suit permanent, rigid joints. Coating colour, ambient temperature and member length do not determine the connection type.

Question 48Metal Fabrication (craft apprenticeship programme)

A fabricator notices a weld bead with a regular herringbone pattern of ripples that are too widely spaced. Which welding parameter should be adjusted?

  1. Electrode coating type
  2. Travel speed Correct answer.
  3. Shielding gas composition
  4. Workpiece earth clamp position

Explanation

Ripple spacing reflects how far the arc moves during each oscillation of the molten pool, so it is controlled mainly by travel speed. Gas composition, coating type and earth clamp position do not set ripple pitch.

Question 49Metal Fabrication (craft apprenticeship programme)

Why is a weld symbol with a flag placed at the junction of the reference line and the arrow used on a fabrication drawing?

  1. It indicates a full-penetration weld
  2. It shows the weld is to be ground flush
  3. It specifies that the weld is to be made on site rather than in the workshop Correct answer.
  4. It specifies a staggered intermittent weld

Explanation

The supplementary flag symbol means the weld is a field weld, performed at the site of final assembly rather than in the fabrication shop. Full penetration, flush finishing and staggered welds use different symbol elements.

Question 50Metal Fabrication (craft apprenticeship programme)

A fabricated steel tank shows a crack running from the weld toe into the parent metal shortly after commissioning. Which cause is most likely?

  1. Hydrogen-assisted cold cracking in a hard heat-affected zone Correct answer.
  2. Incorrect weld symbol on the drawing
  3. Use of a new grinding disc
  4. Excessive weld spatter on the surface

Explanation

Cracks at the weld toe after cooling often indicate hydrogen-assisted cold cracking, promoted by a hard HAZ, hydrogen from moisture and high restraint. Spatter, symbol errors and grinding discs do not cause this failure mode.