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MSCE Metalwork study materials
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MSCE Metalwork practice questions

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Question 1Occupational Health, Safety and Workshop Practice

In a metalwork workshop, which type of fire extinguisher is the correct choice for a fire involving magnesium swarf and filings?

  1. Carbon dioxide extinguisher
  2. Class D dry powder extinguisher Correct answer.
  3. Water stored-pressure extinguisher
  4. Foam extinguisher

Explanation

Combustible metals such as magnesium, aluminium and sodium require a Class D extinguisher, which smothers the burning metal with a specialised powder. Water, foam and CO2 are ineffective on metal fires and can react violently, so they must never be used on magnesium swarf.

Question 2Occupational Health, Safety and Workshop Practice

What is the main purpose of fitting a machine guard to a bench pedestal drill?

  1. To improve the accuracy of the drilled hole
  2. To keep the operator's hands and clothing away from the rotating chuck and drill Correct answer.
  3. To reduce the noise level produced by the motor
  4. To collect metal swarf as it is cut

Explanation

Guards on drilling machines, such as chuck guards and interlocked pulleys, physically prevent contact between the operator and rotating parts. Their function is protective, not to control noise, collect swarf or improve hole accuracy.

Question 3Occupational Health, Safety and Workshop Practice

Which item of personal protective equipment is essential when chipping or grinding to protect the eyes from flying particles?

  1. Cut-resistant gloves
  2. Ear defenders
  3. Impact-rated safety goggles or a face shield Correct answer.
  4. A dust mask

Explanation

Flying chips and abrasive particles from chipping and grinding travel at high speed, so impact-rated eye protection such as goggles or a face shield is required. Other PPE items address different hazards and do not protect the eyes.

Question 4Occupational Health, Safety and Workshop Practice

Why should compressed air never be used to blow metal dust off clothing or skin in a workshop?

  1. It can force particles into the eyes and skin and cause serious injury Correct answer.
  2. It cools the body too quickly
  3. It removes the protective oil from the skin
  4. It damages the fabric of the overalls

Explanation

Compressed air can drive metal particles, dust and swarf into the eyes or through the skin, and it can also create airborne contamination. Brushes, vacuum extraction or low-pressure air are used instead for cleaning.

Question 5Occupational Health, Safety and Workshop Practice

What does the abbreviation COSHH refer to in a metalwork workshop context?

  1. Code of Safe Handling of Handtools
  2. Control of Substances Hazardous to Health Correct answer.
  3. Control of Surface Treatment and Heat Treatment
  4. Certification of Sheet-metal and Tool Hardening

Explanation

COSHH stands for Control of Substances Hazardous to Health, the framework requiring assessment and control of exposure to substances such as cutting fluids, solvents, dusts and welding fume. It underpins safe handling of materials that can harm health.

Question 6Occupational Health, Safety and Workshop Practice

Why is loose clothing such as ties, sleeves and jewellery prohibited when operating a centre lathe?

  1. Loose clothing can damage the finish of the workpiece
  2. Loose items can be caught by the rotating workpiece or chuck and pull the operator in Correct answer.
  3. Loose clothing can cause static electricity build-up
  4. Loose items can interfere with the coolant flow

Explanation

Rotating chucks and workpieces entangle loose clothing, ties and jewellery, dragging the operator towards the machine. Close-fitting clothing and removed jewellery are required to eliminate the entanglement hazard.

Question 7Occupational Health, Safety and Workshop Practice

A workshop uses a grinding wheel that is rated for a maximum speed of 3000 rpm. The machine spindle runs at 3500 rpm. What is the correct course of action?

  1. Mount the wheel and fit an additional guard
  2. Mount the wheel and reduce the feed pressure during grinding
  3. Mount the wheel and shorten the grinding cycles
  4. Do not mount the wheel and select one rated for at least the spindle speed Correct answer.

Explanation

A grinding wheel must never be run above its marked maximum speed because centrifugal force can burst the wheel and throw fragments. The correct action is to use a wheel rated for at least the machine's spindle speed, not to compensate with operating practice.

Question 8Occupational Health, Safety and Workshop Practice

Why is a face shield alone considered insufficient eye protection when using a pedestal grinder?

  1. Particles can pass around or under the shield, so safety glasses are also worn Correct answer.
  2. A face shield is too heavy for prolonged use
  3. A face shield interferes with the coolant supply
  4. A face shield restricts the view of the wheel

Explanation

Face shields protect the whole face but leave gaps at the sides and bottom through which small particles can reach the eyes. Impact-rated safety spectacles or goggles are therefore worn underneath the shield for primary eye protection.

Question 9Occupational Health, Safety and Workshop Practice

A container of solvent is left open at a bench in a workshop with poor ventilation. Which risk does this create?

  1. Increased risk of metal fume fever
  2. Reduced effectiveness of the cutting fluid
  3. Corrosion of the bench surface only
  4. Inhalation of vapour and formation of a flammable atmosphere Correct answer.

Explanation

Volatile solvents release vapour that can be inhaled and can form a flammable mixture with air if ventilation is inadequate. Containers should be kept closed and used with local exhaust ventilation to control both health and fire risks.

Question 10Occupational Health, Safety and Workshop Practice

What is the purpose of the tongue guard on an abrasive cut-off saw or bench grinder?

  1. To hold the wheel in alignment during dressing
  2. To limit the gap between the wheel and the guard so that fragments and fingers are kept clear Correct answer.
  3. To guide the workpiece into the cutting zone
  4. To direct sparks away from the operator

Explanation

The tongue or adjustable guard is set close to the wheel to minimise the open gap, reducing the risk of a workpiece or fragment being drawn in and limiting exposure to the rotating wheel. It must be adjusted as the wheel wears.

Question 11Occupational Health, Safety and Workshop Practice

A welder is working in a confined metal tank. Which control is most important to prevent asphyxiation?

  1. Continuous forced ventilation with atmospheric monitoring and a standby person outside Correct answer.
  2. Wearing a welding helmet with a dark filter
  3. Using a fire blanket inside the tank
  4. Wearing flame-retardant overalls

Explanation

Confined spaces can accumulate inert or toxic gases and consume oxygen, so continuous ventilation, atmospheric testing and a trained standby person are essential. PPE and fire precautions do not address the oxygen-deficiency hazard.

Question 12Occupational Health, Safety and Workshop Practice

Why is it important to report a small cut on the hand before starting work with a cutting fluid or solvent?

  1. The cut will prevent the machine guard from closing
  2. The cut will affect the accuracy of measurements
  3. The cut will blunt the cutting tool
  4. Chemicals can enter the wound and cause infection or dermatitis Correct answer.

Explanation

Cutting fluids, solvents and oils can penetrate broken skin, causing irritation, infection or dermatitis, so cuts must be cleaned, dressed and covered. Waterproof dressings or gloves are used as appropriate.

Question 13Occupational Health, Safety and Workshop Practice

What is the safe procedure for clearing swarf from around a rotating drill on a pedestal drill?

  1. Use a gloved hand while the drill is still turning
  2. Stop the machine and use a brush or hook before restarting Correct answer.
  3. Use a compressed-air line to blow the swarf clear
  4. Reduce the spindle speed and clear the swarf by hand

Explanation

Swarf must only be removed after the spindle has stopped, using a brush or a hook, because swarf is sharp and can be caught by the rotating drill. Clearing by hand, even at low speed, risks serious cuts and entanglement.

Question 14Occupational Health, Safety and Workshop Practice

A worker must lift a heavy steel billet from the floor. Which approach best reduces the risk of back injury?

  1. Assess the load, bend the knees, keep the back straight and lift close to the body, using mechanical aid if needed Correct answer.
  2. Keep the legs straight and bend at the waist to reach the billet
  3. Lift the billet quickly with outstretched arms
  4. Twist the torso while lifting to place the billet on the bench

Explanation

Safe manual handling keeps the load close to the body, uses the leg muscles with a straight back and avoids twisting, and mechanical aids should be used for heavy or awkward loads. This reduces the compressive and shear forces on the lower back.

Question 15Occupational Health, Safety and Workshop Practice

Why are aluminium and magnesium dusts generated by grinding considered a serious fire and explosion risk?

  1. The dust melts at room temperature
  2. The dust is radioactive
  3. Fine metal dust can form an explosive cloud and burn intensely when suspended in air Correct answer.
  4. The dust reacts with water to produce oxygen

Explanation

Finely divided reactive metals present a large surface area, and when suspended in air they can form a dust cloud that ignites and propagates a rapid explosion. Extraction and housekeeping are used to prevent accumulation of such dust.

Question 16Occupational Health, Safety and Workshop Practice

A lathe operator needs to measure a workpiece. What is the correct safe practice?

  1. Measure with a steel rule while the workpiece rotates
  2. Stop the spindle and wait for it to come to rest before measuring Correct answer.
  3. Measure with a caliper while the workpiece rotates slowly
  4. Ask a second person to hold the caliper against the rotating workpiece

Explanation

Measuring a rotating workpiece exposes the operator's hands and the instrument to the chuck and rotating surfaces, so the spindle must be stopped and allowed to come to rest before any measurement. This eliminates the entanglement and cut hazard.

Question 17Occupational Health, Safety and Workshop Practice

Which combination best describes the hierarchy of control as applied to a hazardous fume source in a welding bay?

  1. Provide training first, then extraction, then substitution
  2. Use PPE first, then reduce the welding current
  3. Eliminate or substitute the process, then use engineering controls such as extraction, then administrative controls, with PPE as the last line Correct answer.
  4. Rely on a respirator first, then add extraction if symptoms appear

Explanation

The hierarchy of control places elimination and substitution at the top, followed by engineering controls such as local exhaust ventilation, then administrative controls and finally PPE. PPE is the last line of defence because it protects only the wearer and depends on correct use.

Question 18Occupational Health, Safety and Workshop Practice

An angle grinder is fitted with a cutting disc that shows a slight chip on its edge. What is the correct action?

  1. Use the disc only for light cuts until it wears down
  2. Remove the damaged disc from service and fit an undamaged disc of the correct type and speed rating Correct answer.
  3. Dress the chip away on the machine at full speed
  4. Turn the disc around so the damaged edge faces the guard

Explanation

A chipped or cracked bonded abrasive disc can fail catastrophically at operating speed, so it must be withdrawn from service. Discs must also match the machine's speed rating and be used only for their intended application.

Question 19Occupational Health, Safety and Workshop Practice

A workshop stores oxygen and acetylene cylinders together in a locked compound. Which arrangement is correct?

  1. Keep cylinders close to the welding bay for quick access
  2. Store full and empty cylinders mixed together to save space
  3. Lay all cylinders horizontally to prevent them rolling
  4. Store oxygen and fuel-gas cylinders separately with fire-resistant segregation, upright and secured Correct answer.

Explanation

Oxygen and fuel-gas cylinders should be stored separately, upright and secured against falling, with fire-resistant separation to prevent a fire involving one cylinder from spreading to the other. Cylinders should also be kept away from heat and ignition sources.

Question 20Occupational Health, Safety and Workshop Practice

A risk assessment for a new milling operation identifies exposure to metalworking fluid mist. Which control directly reduces the hazard at source?

  1. Displaying warning signs at the machine
  2. Shortening the machining cycle time
  3. Enclosing the cutting zone and fitting local exhaust ventilation to capture mist Correct answer.
  4. Issuing respirators to all operators

Explanation

Enclosure and local exhaust ventilation capture mist at the point of generation, reducing the concentration in the breathing zone before it can be inhaled. This engineering control is more reliable than PPE or administrative measures.

Question 21Materials, Properties and Selection of Metals

In a tensile test, which point on the stress–strain curve marks the onset of permanent deformation in a ductile metal such as low-carbon steel?

  1. The ultimate tensile strength
  2. The proportional limit at zero stress
  3. The yield point Correct answer.
  4. The fracture point

Explanation

The yield point is the stress at which the metal stops behaving elastically and begins to deform plastically, so the deformation becomes permanent. Below this point the strain is recoverable; beyond it, residual strain remains after unloading. The ultimate tensile strength is higher and marks the maximum load, not the onset of plasticity.

Question 22Materials, Properties and Selection of Metals

A metal component must resist indentation and surface wear in service. Which property is most directly measured by a Brinell or Vickers test?

  1. Toughness
  2. Electrical conductivity
  3. Hardness Correct answer.
  4. Ductility

Explanation

Brinell and Vickers tests press a hard indenter into the surface and relate the size of the impression to hardness, so they measure resistance to indentation directly. Ductility is measured by elongation or reduction of area in a tensile test. Toughness combines strength and ductility and is assessed by impact testing.

Question 23Materials, Properties and Selection of Metals

Which of the following is a ferrous metal?

  1. Mild steel Correct answer.
  2. Copper
  3. Aluminium alloy 6082
  4. Zinc

Explanation

Ferrous metals are those based on iron, and mild steel is an iron–carbon alloy containing a small percentage of carbon. Aluminium, copper and zinc are all non-ferrous because they contain no iron as the base element. This distinction governs properties such as magnetism, density and corrosion behaviour.

Question 24Materials, Properties and Selection of Metals

What is the approximate carbon content of mild steel?

  1. 3.0% to 4.5%
  2. 0.05% to 0.25% Correct answer.
  3. 1.5% to 2.5%
  4. 0.6% to 1.0%

Explanation

Mild (low-carbon) steel contains roughly 0.05% to 0.25% carbon, which gives good ductility and weldability with moderate strength. Higher carbon contents raise hardness but reduce toughness and weldability. Cast irons generally contain well above 2% carbon.

Question 25Materials, Properties and Selection of Metals

Which heat treatment is used to soften a metal and relieve internal stresses after cold working, making it easier to machine?

  1. Case hardening
  2. Annealing Correct answer.
  3. Quenching
  4. Tempering

Explanation

Annealing involves heating the metal and cooling it slowly, usually in the furnace, so that recrystallisation occurs and internal stresses are relieved. The result is a softer, more ductile structure that machines more easily. Quenching and tempering are used to harden and toughen steel, not to soften it.

Question 26Materials, Properties and Selection of Metals

Which metal is the base element of stainless steel, giving it the ability to form a passive oxide film?

  1. Molybdenum
  2. Chromium Correct answer.
  3. Manganese
  4. Nickel

Explanation

Stainless steels contain at least about 10.5% chromium, which forms a thin, self-healing chromium oxide layer on the surface. This passive film protects the underlying metal from corrosion. Nickel and molybdenum improve other properties but do not provide the essential passive layer.

Question 27Materials, Properties and Selection of Metals

A non-destructive test is required to detect internal voids in a cast aluminium component without damaging it. Which method is most suitable?

  1. Spark test
  2. Charpy impact test
  3. Filing test
  4. Radiographic inspection Correct answer.

Explanation

Radiography passes X-rays or gamma rays through the component and reveals internal density variations such as voids, porosity and inclusions on a film or detector. It leaves the component undamaged and is suited to castings. The other methods are destructive or only assess surface or spark characteristics.

Question 28Materials, Properties and Selection of Metals

Which property describes the ability of a metal to be permanently stretched into wire without fracturing?

  1. Ductility Correct answer.
  2. Malleability
  3. Brittleness
  4. Elasticity

Explanation

Ductility is the capacity of a metal to undergo plastic deformation in tension, as when drawn into wire. Malleability is the similar ability under compressive deformation, as in rolling or hammering into sheet. The two properties are related but describe different loading conditions.

Question 29Materials, Properties and Selection of Metals

A steel bracket is quenched from above its critical temperature and becomes very hard but brittle. Which treatment should follow to improve toughness while retaining useful hardness?

  1. Normalising
  2. Carburising
  3. Annealing
  4. Tempering Correct answer.

Explanation

Tempering reheats the quenched steel to a temperature below the critical range and holds it, allowing some of the hard martensite to transform and relieving quenching stresses. This reduces brittleness while preserving a useful level of hardness. Annealing and normalising would soften the part more than intended.

Question 30Materials, Properties and Selection of Metals

A workshop needs a steel with good weldability and high ductility for a lightly loaded guard. Which material is the most appropriate choice?

  1. High-carbon tool steel
  2. Grey cast iron
  3. Mild steel Correct answer.
  4. Austenitic stainless steel

Explanation

Mild steel has low carbon content, which gives good ductility and weldability at low cost, making it ideal for lightly loaded fabrications. High-carbon steel is harder but prone to cracking on welding. Cast iron is brittle and not readily welded, and stainless steel is more expensive than the duty requires.

Question 31Materials, Properties and Selection of Metals

In a plain-carbon steel, increasing the carbon content from 0.2% to 0.8% will generally produce which change in properties?

  1. No change in mechanical properties
  2. Higher hardness and lower ductility Correct answer.
  3. Higher electrical conductivity
  4. Higher ductility and lower hardness

Explanation

As carbon content rises, more pearlite or cementite forms in the microstructure, which increases strength and hardness but reduces ductility and toughness. This is why high-carbon steels are used for cutting tools and springs rather than for forming operations. The change is a direct consequence of the iron–carbon phase relationships.

Question 32Materials, Properties and Selection of Metals

Which alloying element is added to steel to improve machinability by forming brittle chips and acting as a chip breaker?

  1. Sulphur Correct answer.
  2. Vanadium
  3. Chromium
  4. Nickel

Explanation

Small additions of sulphur form manganese sulphide inclusions that promote chip breaking, improving machinability in free-cutting steels. Chromium and nickel are added for corrosion resistance and toughness. Vanadium is used for grain refinement and strengthening, not for machinability.

Question 33Materials, Properties and Selection of Metals

A component is to be manufactured by hot forging. Which property is most important in the starting billet?

  1. Good hot ductility Correct answer.
  2. High room-temperature hardness
  3. Low thermal conductivity
  4. High electrical resistivity

Explanation

Hot forging requires the metal to deform plastically without cracking at elevated temperature, so hot ductility is the key property. High room-temperature hardness is irrelevant once the metal is hot and may indicate poor forgeability. Thermal and electrical properties have little bearing on the forging operation.

Question 34Materials, Properties and Selection of Metals

Which of the following best describes the structure of austenite in steel?

  1. Hexagonal close-packed
  2. Amorphous
  3. Face-centred cubic Correct answer.
  4. Body-centred cubic

Explanation

Austenite is the face-centred cubic phase of iron that is stable at high temperature in plain-carbon steels and can dissolve more carbon than ferrite. Its close-packed structure gives good ductility and allows it to be retained at room temperature in some alloy steels. Ferrite, by contrast, is body-centred cubic.

Question 35Materials, Properties and Selection of Metals

A steel component is to be case hardened so that the surface resists wear while the core remains tough. Which process achieves this by diffusing carbon into the surface?

  1. Induction annealing
  2. Stress relieving
  3. Tempering
  4. Carburising Correct answer.

Explanation

Carburising heats the steel in a carbon-rich atmosphere so that carbon diffuses into the surface layer, which can then be hardened by quenching while the low-carbon core stays tough. Tempering and stress relieving modify existing structures rather than adding carbon. Induction annealing softens selected regions rather than hardening the case.

Question 36Materials, Properties and Selection of Metals

Which of the following metals has a hexagonal close-packed crystal structure at room temperature?

  1. Aluminium
  2. Copper
  3. Iron at room temperature
  4. Magnesium Correct answer.

Explanation

Magnesium has a hexagonal close-packed structure, which offers fewer slip systems and makes it less formable at room temperature than face-centred cubic metals. Aluminium and copper are face-centred cubic, and iron at room temperature is body-centred cubic. Crystal structure strongly influences ductility and forming behaviour.

Question 37Materials, Properties and Selection of Metals

A galvanised steel sheet is specified for an outdoor enclosure. What is the primary role of the zinc coating?

  1. It acts as a sacrificial anode protecting the steel Correct answer.
  2. It increases the tensile strength of the steel
  3. It raises the melting point of the steel
  4. It improves the machinability of the steel

Explanation

Zinc is more electrochemically active than steel, so it corrodes preferentially and protects the steel even where the coating is scratched. This is known as sacrificial or cathodic protection. The coating does not significantly change the steel's strength, melting point or machinability.

Question 38Materials, Properties and Selection of Metals

Which test is used to determine the toughness of a metal by measuring the energy absorbed when a notched specimen is broken by a single blow?

  1. Macro-etch test
  2. Tensile test
  3. Vickers hardness test
  4. Charpy impact test Correct answer.

Explanation

The Charpy impact test strikes a notched specimen with a swinging pendulum and records the energy absorbed before fracture, which indicates toughness. A tensile test measures strength and ductility but not impact energy. Hardness and macro-etch tests give different information.

Question 39Materials, Properties and Selection of Metals

A steel contains 0.8% carbon and is slowly cooled from the austenitic region. Which microstructure is expected at room temperature?

  1. Fully pearlitic Correct answer.
  2. Fully ferritic
  3. Fully austenitic
  4. Fully martensitic

Explanation

At the eutectoid composition of about 0.8% carbon, slow cooling from austenite produces pearlite, an alternating lamellar structure of ferrite and cementite. There is no free ferrite or cementite because the composition coincides with the eutectoid point. Austenite is not stable at room temperature and martensite requires rapid quenching.

Question 40Materials, Properties and Selection of Metals

Which statement correctly explains why a metal with a face-centred cubic structure is generally more ductile than one with a hexagonal close-packed structure?

  1. FCC metals contain no grain boundaries
  2. HCP has a higher melting point than FCC in all metals
  3. HCP metals cannot be work hardened
  4. FCC has more independent slip systems available for plastic deformation Correct answer.

Explanation

Face-centred cubic metals have four slip planes each with three slip directions, giving twelve independent slip systems, so grains can accommodate deformation in many orientations. Hexagonal close-packed metals have far fewer independent slip systems at room temperature, which limits ductility. The number of slip systems is the key structural factor.

Question 41Materials, Properties and Selection of Metals

A hardened steel component shows a soft surface after quenching. Which condition is the most likely cause?

  1. Use of a coarse grinding wheel
  2. Excessive tempering time at low temperature
  3. Insufficient coolant during machining
  4. Decarburisation of the surface during heating Correct answer.

Explanation

Decarburisation removes carbon from the surface layer during heating in an oxidising atmosphere, lowering the hardenability of that layer so it cannot form hard martensite. The result is a soft skin over a harder core. The other options affect surface finish or residual stress but not the carbon content that governs hardening.

Question 42Materials, Properties and Selection of Metals

Which combination of properties makes an aluminium alloy rather than mild steel the better choice for an aircraft skin panel?

  1. High strength-to-weight ratio with adequate fatigue resistance Correct answer.
  2. Greater magnetic permeability and higher hardness
  3. Lower cost per kilogram with higher stiffness
  4. Higher density with lower melting point

Explanation

Aluminium alloys offer a high strength-to-weight ratio, which reduces structural mass in aircraft, and suitable alloys are developed for fatigue resistance. Mild steel is denser and would add weight for the same strength. Cost and stiffness per unit mass do not favour steel in this application.

Question 43Materials, Properties and Selection of Metals

A welded mild steel fabrication develops cracks in the heat-affected zone. Which factor is the most probable metallurgical cause?

  1. Grain refinement caused by the weld thermal cycle
  2. Hydrogen-assisted cracking in a hardened heat-affected zone Correct answer.
  3. Excessive ductility in the parent metal
  4. Low sulphur content in the filler metal

Explanation

The heat-affected zone can transform to hard martensite on rapid cooling, and combined with dissolved hydrogen from moisture in consumables it becomes susceptible to hydrogen-assisted cold cracking. Preheating and using low-hydrogen consumables reduce the risk. Ductility, grain refinement and low sulphur do not cause this type of cracking.

Question 44Materials, Properties and Selection of Metals

In the iron–carbon equilibrium diagram, what is the significance of the eutectoid point at approximately 0.8% carbon and 723 °C?

  1. Ferrite transforms into cementite on heating
  2. Austenite transforms directly into pearlite on slow cooling Correct answer.
  3. Carbon becomes insoluble in iron above this temperature
  4. The metal melts completely at this temperature

Explanation

At the eutectoid point, austenite of eutectoid composition decomposes on slow cooling into the lamellar aggregate pearlite, with no proeutectoid phase forming. This gives a fully pearlitic microstructure. Melting occurs at much higher temperatures, and carbon solubility in austenite is high above this point rather than zero.

Question 45Hand Tools, Measuring and Marking Out

A fitter needs to scribe a line parallel to a machined edge on a steel plate. Which hand tool is designed specifically for this operation?

  1. Spring dividers
  2. Jenny caliper
  3. Odd-leg caliper Correct answer.
  4. Surface gauge

Explanation

An odd-leg caliper (also called a hermaphrodite caliper) has one straight leg and one curved leg, so the curved leg can be run along a datum edge while the straight leg scribes a parallel line. Dividers have two straight pointed legs and are used for circles and arcs, not edge-following offsets.

Question 46Hand Tools, Measuring and Marking Out

Which tool is the correct choice for checking that a machined face is square to an adjacent face on a small steel block?

  1. Inside micrometer
  2. Vernier height gauge
  3. Engineer's try square Correct answer.
  4. Combination set protractor head

Explanation

An engineer's try square has a hardened steel blade set permanently at 90 degrees in a stock, so it directly compares two adjacent faces for squareness. The stock is pressed against one face and the blade is offered to the other while the work is held to a light source.

Question 47Hand Tools, Measuring and Marking Out

What is the standard included angle of the point on a engineer's centre punch used for marking hole positions in mild steel?

  1. 120 degrees
  2. 60 degrees
  3. 45 degrees
  4. 90 degrees Correct answer.

Explanation

A centre punch is ground to a 90 degree included angle so it produces a distinct conical indentation that steers a drill point without the punch wandering. The sharper 60 degree angle is characteristic of a dot punch, which is used for lighter witness marks.

Question 48Hand Tools, Measuring and Marking Out

On a metric vernier caliper with a main scale graduated in 0.5 mm and 50 vernier divisions, what is the least count?

  1. 0.1 mm
  2. 0.02 mm Correct answer.
  3. 0.01 mm
  4. 0.05 mm

Explanation

Least count equals the value of one main-scale division divided by the number of vernier divisions. Here 0.5 mm divided by 50 gives 0.02 mm, the smallest difference the instrument can resolve.

Question 49Hand Tools, Measuring and Marking Out

A vernier caliper reads a main scale value of 24.5 mm with the 13th vernier line coinciding on a 0.02 mm instrument. What is the measured size?

  1. 24.50 mm
  2. 24.63 mm
  3. 25.13 mm
  4. 24.76 mm Correct answer.

Explanation

The vernier contribution is the coinciding line number multiplied by the least count: 13 x 0.02 mm = 0.26 mm. Adding this to the main scale reading of 24.5 mm gives 24.76 mm.

Question 50Hand Tools, Measuring and Marking Out

Why is a scriber used on steel plate normally fitted with a hardened and finely ground point?

  1. To let the scriber be used as a centre punch
  2. To increase the depth of cut when marking thick plate
  3. To allow the point to be magnetised for holding layout blue
  4. To produce a fine, accurate line without tearing the surface Correct answer.

Explanation

A hardened, finely ground point slides across the surface and leaves a narrow, crisp line that can be read accurately, instead of a ragged scratch. Hardening also keeps the point from dulling quickly on steel.