I85PREP
⌘ K
JCE Metalwork study materials
JCE Metalwork study resources

JCE Metalwork practice questions

One question at a time. Build your JCE Metalwork understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Materials and Material Properties

In metalwork, the term 'ferrous' is applied to a metal because of which principal constituent?

  1. Copper
  2. Aluminium
  3. Zinc
  4. Iron Correct answer.

Explanation

Ferrous metals are those whose main constituent is iron, which gives them magnetic character and makes them prone to rusting. Copper, aluminium and zinc are all non-ferrous and contain no iron as their base element.

Question 2Materials and Material Properties

A workshop needs a steel that resists corrosion without any applied coating. Which material is the most suitable choice?

  1. Stainless steel Correct answer.
  2. Cast iron
  3. Mild steel
  4. High-carbon steel

Explanation

Stainless steel contains chromium, which forms a thin passive oxide layer that protects the surface from corrosion. Mild steel, cast iron and high-carbon steel all lack sufficient chromium and will rust readily if unprotected.

Question 3Materials and Material Properties

Which property describes a metal's ability to be drawn out into thin wire without fracture?

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

Explanation

Ductility is the property that allows a metal to be stretched or drawn into wire under tensile force. Malleability concerns flattening into sheet under compressive force, while hardness and brittleness describe resistance to indentation and tendency to fracture respectively.

Question 4Materials and Material Properties

Which non-ferrous metal is chosen for electrical conductors because of its very high conductivity?

  1. Copper Correct answer.
  2. Lead
  3. Tungsten
  4. Tin

Explanation

Copper combines excellent electrical conductivity with good ductility, making it the standard choice for wiring and busbars. Lead, tin and tungsten are all poorer conductors and are used for other purposes.

Question 5Materials and Material Properties

A metal is described as 'brittle'. What behaviour does this describe when the material is loaded?

  1. It fractures with little or no plastic deformation Correct answer.
  2. It deforms permanently before breaking
  3. It returns to its original shape after unloading
  4. It flows slowly under a constant load

Explanation

Brittleness means the material fractures with little plastic deformation, so there is almost no warning before failure. Permanent deformation describes ductile behaviour, elastic recovery describes elasticity, and slow flow under sustained load describes creep.

Question 6Materials and Material Properties

Which material is a thermosetting plastic commonly used in metalwork for its heat resistance and electrical insulation?

  1. Polyvinyl chloride (PVC)
  2. Polystyrene
  3. Epoxy resin Correct answer.
  4. Polyethylene

Explanation

Epoxy resin is a thermosetting polymer that cures irreversibly and offers good heat resistance and electrical insulation. Polyethylene, PVC and polystyrene are thermoplastics that soften on reheating.

Question 7Materials and Material Properties

What does the term 'alloy' mean when applied to a metal?

  1. A metal that has been heat treated
  2. A mixture of two or more elements where at least one is a metal Correct answer.
  3. A metal coated with another metal
  4. A pure metal with no impurities

Explanation

An alloy is a mixture of two or more elements in which at least one is a metal, deliberately combined to improve properties. Heat treatment and coating are processes, while a pure metal is by definition not an alloy.

Question 8Materials and Material Properties

In a metals workshop, which property is tested by the simple file test?

  1. Hardness Correct answer.
  2. Density
  3. Thermal conductivity
  4. Tensile strength

Explanation

The file test assesses hardness by judging how readily a file cuts into the surface of the metal. Tensile strength, thermal conductivity and density each require different, more involved test methods.

Question 9Materials and Material Properties

A steel component must be tough enough to withstand repeated impact without cracking. Which property is most important?

  1. Electrical conductivity
  2. Malleability
  3. Impact resistance (toughness) Correct answer.
  4. Thermal expansion

Explanation

Toughness is the ability to absorb energy and deform plastically before fracturing, which is exactly what repeated impact demands. Conductivity, malleability and thermal expansion do not describe resistance to sudden shock loading.

Question 10Materials and Material Properties

Why is chromium added to stainless steel during alloying?

  1. To reduce the density
  2. To form a protective passive oxide layer Correct answer.
  3. To lower the melting point
  4. To increase the electrical conductivity

Explanation

Chromium is added because it forms a thin, adherent passive oxide film that shields the steel from further attack. It does not primarily lower melting point, boost conductivity or reduce density.

Question 11Materials and Material Properties

What is the main reason for adding carbon to steel?

  1. To improve electrical insulation
  2. To make the steel non-magnetic
  3. To increase hardness and strength Correct answer.
  4. To prevent any deformation during machining

Explanation

Carbon content controls hardness and strength in steel; higher carbon gives greater hardness but lower ductility. It does not provide insulation, does not make steel non-magnetic and does not stop deformation during machining.

Question 12Materials and Material Properties

A workpiece must be shaped by hammering into a curved form without cracking. Which combination of properties is most desirable?

  1. High malleability and good ductility Correct answer.
  2. Low toughness and high stiffness
  3. High hardness and low ductility
  4. High brittleness and high hardness

Explanation

Hammering into a curved form requires the metal to deform plastically without fracture, so malleability and ductility are needed. Brittleness, low ductility and low toughness all promote cracking under such forming.

Question 13Materials and Material Properties

What distinguishes a thermosetting plastic from a thermoplastic in terms of behaviour on reheating?

  1. A thermosetting plastic is always transparent
  2. A thermosetting plastic cures irreversibly and will not soften on reheating Correct answer.
  3. A thermosetting plastic melts at a lower temperature than any thermoplastic
  4. A thermosetting plastic softens and can be remoulded repeatedly

Explanation

Thermosetting plastics undergo an irreversible chemical cure, so they char or degrade rather than soften when reheated. Thermoplastics, by contrast, soften on heating and can be remoulded repeatedly.

Question 14Materials and Material Properties

Which material is most suitable for a component that must be light, corrosion resistant and easily formed into thin sheet for cladding?

  1. Cast iron
  2. Lead
  3. High-carbon steel
  4. Aluminium Correct answer.

Explanation

Aluminium is light, naturally corrosion resistant through its oxide film, and readily rolled into thin sheet for cladding. Cast iron is heavy and brittle, lead is dense and toxic, and high-carbon steel is hard and less formable.

Question 15Materials and Material Properties

What is the purpose of normalising a steel component after hot working?

  1. To make the steel permanently magnetic
  2. To refine the grain structure and relieve internal stresses Correct answer.
  3. To apply a decorative surface colour
  4. To increase the carbon content

Explanation

Normalising heats the steel above its critical range and allows it to cool in still air, refining the grain and relieving internal stresses. It does not add carbon, colour the surface or set permanent magnetism.

Question 16Materials and Material Properties

Which test would best reveal a surface hardness value in a workshop setting?

  1. A hardness indentation test Correct answer.
  2. A bend test
  3. A spark test
  4. A magnetic test

Explanation

A hardness indentation test presses a known indenter into the surface and relates the impression to a hardness value. Bend, spark and magnetic tests assess ductility, alloy type and magnetism respectively.

Question 17Materials and Material Properties

A steel is described as having good 'fatigue resistance'. What does this mean?

  1. It resists deformation at high temperature
  2. It resists failure under repeated cyclic loading Correct answer.
  3. It resists indentation by a hard point
  4. It resists attack by corrosive chemicals

Explanation

Fatigue resistance is the ability to endure repeated cycles of stress without initiating or propagating a crack. Corrosion resistance, hardness and creep resistance each describe different behaviours.

Question 18Materials and Material Properties

Why is a low-carbon (mild) steel often preferred for general fabrication such as brackets and frames?

  1. It has the highest melting point of all steels
  2. It is fully corrosion resistant without treatment
  3. It has the highest possible hardness
  4. It is easily welded and formed and is relatively cheap Correct answer.

Explanation

Mild steel has low carbon content, which makes it ductile, readily welded and inexpensive, suiting general fabrication. It is not the hardest steel, it still rusts, and its melting point is not exceptional.

Question 19Materials and Material Properties

What is the effect of increasing the carbon content of plain carbon steel?

  1. Ductility increases while hardness falls
  2. Corrosion resistance increases sharply
  3. Hardness and tensile strength increase while ductility falls Correct answer.
  4. Density decreases markedly

Explanation

Raising carbon content increases hardness and tensile strength but reduces ductility, making the steel less forgiving to form. Corrosion resistance and density are not significantly improved by carbon alone.

Question 20Materials and Material Properties

An engineer selects a material for a component that will operate at elevated temperature under a constant load for long periods. Which property is the critical concern?

  1. Optical reflectivity
  2. Magnetic permeability
  3. Malleability
  4. Creep resistance Correct answer.

Explanation

Creep is time-dependent deformation under sustained load, and it becomes significant at elevated temperature, so creep resistance is the critical property. Malleability, reflectivity and permeability do not address sustained-load behaviour at temperature.

Question 21Materials and Material Properties

Why does quenching steel in water after heating produce a harder material than slow cooling in air?

  1. Rapid cooling traps a harder transformation structure in the steel Correct answer.
  2. Rapid cooling removes carbon from the steel
  3. Rapid cooling converts the steel into a non-ferrous alloy
  4. Rapid cooling increases the chromium content

Explanation

Fast cooling suppresses the softer transformation products and traps a harder structure such as martensite, raising hardness. Quenching does not remove carbon, add chromium or change the metal into a non-ferrous alloy.

Question 22Materials and Material Properties

Which comparison correctly describes cast iron relative to mild steel?

  1. Cast iron has higher carbon content and is more brittle Correct answer.
  2. Cast iron has no carbon content at all
  3. Cast iron has lower carbon content and is more ductile
  4. Cast iron is a non-ferrous alloy of copper and tin

Explanation

Cast iron contains a much higher carbon content than mild steel, which makes it hard and wear resistant but relatively brittle and weak in tension. It remains a ferrous material and is not an alloy of copper and tin.

Question 23Materials and Material Properties

A component must be both hard on the surface and tough in the core. Which treatment best achieves this combination?

  1. Pickling
  2. Galvanising
  3. Case hardening Correct answer.
  4. Full annealing

Explanation

Case hardening enriches and hardens the outer layer while leaving the core relatively soft and tough, giving a wear-resistant surface on a shock-resistant body. Annealing softens the whole section, while galvanising and pickling are surface treatments for corrosion protection and cleaning.

Question 24Materials and Material Properties

Which material property explains why a metal can be bent and then spring back to its original shape when the load is removed?

  1. Thermal conductivity
  2. Elasticity Correct answer.
  3. Plasticity
  4. Brittleness

Explanation

Elasticity is the ability to recover the original shape after a load is removed, provided the yield point has not been exceeded. Plasticity gives permanent deformation, brittleness gives fracture and conductivity concerns heat flow.

Question 25Materials and Material Properties

Which property of aluminium makes it suitable for aircraft skin panels despite its lower strength than steel?

  1. Its high strength-to-weight ratio Correct answer.
  2. Its high melting point
  3. Its very high density
  4. Its strong magnetic response

Explanation

Aluminium offers a high strength-to-weight ratio, so structures can be light yet adequately strong. Its low density, non-magnetic nature and comparatively low melting point do not explain its use in aircraft skin.

Question 26Materials and Material Properties

A workshop stores a length of copper tube alongside a length of brass rod. Which statement correctly describes the relationship between these two materials?

  1. Brass is an alloy of copper and zinc, so it is not a pure metal like the copper tube. Correct answer.
  2. Brass is a thermoplastic made from copper powder and a resin binder.
  3. Both materials are pure metals because they share the same reddish colour.
  4. Brass is a pure metal and the copper tube is an alloy of brass and tin.

Explanation

Brass is produced by melting copper together with zinc, so it is an alloy rather than a single pure element. The copper tube is essentially unalloyed copper, a pure metallic element with its own characteristic properties. Colour alone does not indicate purity, since many copper-based alloys retain a similar appearance.

Question 27Materials and Material Properties

A candidate is given three unlabelled metal bars and told one is mild steel, one is cast iron and one is aluminium. Which simple workshop observation gives the most reliable first indication of which bar is aluminium?

  1. The bar rusts to a red-brown colour after being left damp.
  2. The bar produces bright sparks when touched against a grinding wheel.
  3. The bar feels noticeably lighter than the other two for the same size. Correct answer.
  4. The bar is attracted strongly by a magnet held against it.

Explanation

Aluminium has a density of roughly one third that of steel, so a bar of the same dimensions is clearly lighter in the hand, which is a useful first sorting check in the workshop. Its low density is one of the properties that drives its use in transport and aerospace work. The other observations describe ferrous behaviour rather than aluminium.

Question 28Materials and Material Properties

A batch of mild steel brackets is to be joined by electric arc welding in a school workshop. Which property of the steel most directly governs how easily a sound weld can be produced?

  1. Its coefficient of thermal expansion, which sets the colour of the finished weld bead.
  2. Its electrical conductivity, which determines how quickly the arc can be struck.
  3. Its hardness on the Brinell scale, which fixes the current setting on the welder.
  4. Its weldability, which depends largely on the carbon content and the absence of harmful impurities. Correct answer.

Explanation

Weldability describes how readily a metal can be fused to give a sound joint without cracking or porosity. In plain carbon steels it falls as carbon content rises, which is why low-carbon mild steel is the easiest of the steels to weld. Impurities such as sulphur and phosphorus also degrade weld quality.

Question 29Materials and Material Properties

A component is to be made by pressing sheet metal into a deep cup shape at room temperature. The sheet must stretch considerably without local thinning or splitting. Which property should be specified on the material drawing?

  1. High brittleness so the sheet fractures cleanly at the die edge.
  2. High elastic limit so the sheet returns to flat after each press stroke.
  3. High surface hardness so the die does not mark the finished surface.
  4. High ductility combined with a low yield strength so the sheet flows plastically. Correct answer.

Explanation

Deep drawing relies on the sheet deforming plastically and stretching without necking or tearing, which demands good ductility. A relatively low yield strength lets the metal flow into the die with less force and reduces the risk of splitting. Hardness and a high elastic limit work against this forming requirement.

Question 30Materials and Material Properties

Two parts made from the same aluminium alloy are tested: one in the annealed condition and one after cold rolling to 50 percent reduction. Which explanation best accounts for the difference in their mechanical behaviour?

  1. Cold rolling multiplies dislocations and impedes their movement, raising strength and hardness while reducing ductility. Correct answer.
  2. Cold rolling raises the recrystallisation temperature so the metal re-softens spontaneously at room temperature.
  3. Cold rolling introduces fine cracks throughout the section, which stiffen the metal and raise its elastic modulus.
  4. Cold rolling removes alloying elements from the metal, leaving a purer and therefore stronger material.

Explanation

Working a metal below its recrystallisation temperature, as in cold rolling, generates and tangles dislocations. Their reduced mobility raises yield strength and hardness, the effect known as work hardening, while leaving less capacity for further plastic strain, so ductility falls. Annealing after cold work restores ductility by allowing new grains to form.

Question 31Hand Tools and Bench Skills

In metalwork bench practice, what is the primary purpose of a bench vice fitted with soft jaws?

  1. To bend sheet metal to a controlled radius without a former
  2. To measure the angle of a chamfer while filing
  3. To drive a taper pin into a blind hole
  4. To hold work securely while protecting finished or soft surfaces from marking Correct answer.

Explanation

Soft jaws (often aluminium or fibre) clamp the workpiece firmly while yielding slightly so that finished faces, threads and soft metals are not crushed or scratched. The vice provides holding force only; it does not form, measure or drive anything. Choosing jaw material to match the workpiece is a standard bench decision.

Question 32Hand Tools and Bench Skills

A hacksaw blade is fitted so that the teeth point forward, away from the handle. What is the reason for this convention?

  1. Forward-facing teeth prevent the blade from overheating
  2. The blade cuts on the forward stroke, so the teeth must face that direction Correct answer.
  3. Forward-facing teeth allow the frame to be used upside down
  4. The blade tension screw only engages when teeth face forward

Explanation

Hacksaw teeth are set to cut on the push stroke, so the points must lead away from the handle; fitting the blade backwards makes it rub and skid rather than cut. Tension and frame orientation are unaffected by tooth direction. Overheating is controlled by stroke speed and lubrication, not by tooth orientation.

Question 33Hand Tools and Bench Skills

Which file cut is most appropriate for removing a large amount of mild steel quickly before finishing?

  1. A double-cut bastard file Correct answer.
  2. A double-cut dead smooth file
  3. A single-cut dead smooth file
  4. A single-cut smooth file

Explanation

A bastard cut is coarser than second cut and smooth, and a double cut has two intersecting rows of teeth that clear metal faster. Coarse double-cut files are the standard choice for rapid stock removal on mild steel, with finer files used afterwards. Dead smooth and single-cut smooth files are finishing tools.

Question 34Hand Tools and Bench Skills

When using a centre punch before drilling, what is the correct sequence of operations?

  1. Centre punch first, then scribe the datum lines across the punch mark
  2. Scribe two datum lines, prick the intersection, then enlarge with a centre punch Correct answer.
  3. Drill the pilot hole first, then mark the centre through the hole
  4. Use the centre punch only after the hole is drilled to size

Explanation

Layout lines are scribed first so their intersection locates the hole; a light prick punch mark is then made on the intersection and checked, and finally enlarged with a centre punch to guide the drill. Punching before scribing destroys the reference lines. A punch mark after drilling has no locating function.

Question 35Hand Tools and Bench Skills

What is the function of the 'set' on a hand hacksaw blade?

  1. To make the blade wider at the back than at the teeth
  2. To harden the tooth tips after manufacture
  3. To offset the teeth alternately so the kerf is wider than the blade Correct answer.
  4. To tension the blade within the frame

Explanation

Set is the alternating sideways offset of the teeth, which cuts a kerf wider than the blade body so the blade does not bind in the slot. Hardening is a heat treatment and tensioning is done by the frame screw. Blade taper is a separate feature and does not clear the kerf.

Question 36Hand Tools and Bench Skills

Why should a file be cleaned with a file card rather than by tapping it against the bench?

  1. Tapping removes the temper from the teeth
  2. Tapping is forbidden because it damages the bench surface
  3. Tapping magnetises the file so swarf sticks permanently
  4. Tapping can crack or chip the hardened teeth and will not clear packed pins Correct answer.

Explanation

A file is hard and brittle; striking it can chip teeth and shorten its life, and it does not dislodge soft metal packed between the teeth. A file card with short bristles lifts the pins out without shock. Magnetism and bench damage are not the reason for the rule.

Question 37Hand Tools and Bench Skills

A scriber used for marking out sheet metal should be held so that its point is:

  1. angled away from the straightedge and dragged towards the body
  2. laid flat against the surface and pushed sideways
  3. pressed vertically into the surface and rotated
  4. tilted so the point runs along the edge of the straightedge, with the line drawn once Correct answer.

Explanation

The scriber is tilted so its point follows the edge of the rule or straightedge, and a single firm pass produces a clean, accurate line. Dragging away from the edge lets the point wander, and repeated passes widen the groove and reduce accuracy. Vertical pressure or rotation does not produce a straight layout line.

Question 38Hand Tools and Bench Skills

Which bench tool is used to check that a machined edge is square to a face before further work?

  1. An engineer's try square Correct answer.
  2. A spring divider
  3. A pin punch
  4. A jenny caliper

Explanation

An engineer's try square has a hardened steel blade set at exactly 90 degrees to the stock and is held against the reference face to check squareness. Dividers and jenny calipers transfer or compare distances, and a pin punch drives pins. None of these checks an angle.

Question 39Hand Tools and Bench Skills

A workpiece is being filed in a bench vice and the file chatters and skids across the surface. Which cause is most likely?

  1. The work is held too high above the vice jaws and vibrates Correct answer.
  2. The file is new and has not yet been broken in
  3. The file is being used with a draw-filing motion
  4. The file has too many teeth per inch for the material

Explanation

Work clamped high above the jaws overhangs and flexes, so the file bounces and skids instead of biting. The remedy is to seat the work low in the jaws with minimum overhang. Tooth count affects finish and speed, draw filing is a controlled finishing stroke, and new files need no breaking in.

Question 40Hand Tools and Bench Skills

When cross-peening a rivet head, why is the hammer directed at an angle to the rivet axis rather than straight down?

  1. To allow the rivet to be removed later without drilling
  2. To avoid work-hardening the rivet shank
  3. To spread the shank sideways into the plate thickness
  4. To build the head progressively outwards without bending the shank Correct answer.

Explanation

Angled peening strokes spread the projecting shank outwards to form the head while keeping the shank straight in its hole. Striking straight down tends to bend the shank or flatten it unevenly. Peening does work-harden the metal, and rivets are still removed by drilling or chiselling.

Question 41Hand Tools and Bench Skills

A tap is being used to cut an M8 thread in a blind hole in mild steel. Which practice best reduces the risk of tap breakage?

  1. Applying sideways pressure to keep the tap aligned
  2. Backing the tap off a quarter turn periodically and clearing swarf Correct answer.
  3. Using the taper tap only, without following with a second or plug tap
  4. Turning the tap continuously in one direction until it bottoms

Explanation

Periodically reversing the tap breaks up the chips and prevents them packing in the flutes, which is the usual cause of breakage in blind holes. Continuous forward turning jams chips, and sideways pressure bends the tap. In a blind hole the taper tap cannot reach full thread depth, so a second or plug tap is needed.

Question 42Hand Tools and Bench Skills

Why is a centre punch mark on a layout line often checked with a magnifier or by eye before drilling?

  1. The punch mark must be removed before the drill can start
  2. The punch mark can drift off the intersection and must be corrected while the hole is still small Correct answer.
  3. The punch mark changes the drill diameter required
  4. The punch mark work-hardens the metal and must be softened first

Explanation

A punch struck slightly off the scribed intersection will lead the drill off position, and the error grows with depth. Checking early allows a small correction with a prick punch or a light chisel cut before drilling. The mark does not alter drill size and is never removed before drilling.

Question 43Hand Tools and Bench Skills

Which condition must be met for a file to cut efficiently on a hardened steel surface?

  1. The file must be used with a pulling action only
  2. The file must be lubricated with cutting oil before every stroke
  3. The file must be harder than the work, so hardened steel is normally ground rather than filed Correct answer.
  4. The file must be softer than the work so the teeth wear evenly

Explanation

A file cuts by the hardness of its teeth exceeding that of the work; case-hardened or hardened steel is harder than a standard file and will blunt it, so grinding is used instead. Oil on a file causes swarf to cling and does not make it cut hard steel. Files cut on the forward push stroke.

Question 44Hand Tools and Bench Skills

A die is being used to cut an external thread on a steel rod. Which starting practice gives the straightest thread?

  1. Apply heavy pressure only after the first full turn
  2. Start the die at an angle and let it straighten itself as it cuts
  3. Oil the rod and turn the die backwards to start the thread
  4. Chamfer the rod end and start the die square to the axis with firm downward pressure Correct answer.

Explanation

A chamfer guides the die onto the rod and reduces the initial engagement area, and starting square with steady pressure keeps the thread coaxial. Starting at an angle produces a crossed or drunken thread that cannot be corrected. Backing the die up does not cut a thread at all.

Question 45Hand Tools and Bench Skills

In sheet metal work, why is a hand snips cut made with the blades fully closed at the end of each stroke?

  1. To keep the cut edges aligned and avoid a ragged, stepped cut line Correct answer.
  2. To sharpen the blades by self-honing
  3. To prevent the sheet from work-hardening at the cut
  4. To allow the offcut to be reused without trimming

Explanation

Completing each stroke before advancing keeps the blades registered with the previous cut, so the line stays straight and the edges meet cleanly. Short, nibbling strokes produce a stepped, ragged edge. Snips do not self-sharpen, and cutting does not work-harden the sheet edge significantly.

Question 46Hand Tools and Bench Skills

A flat surface is being checked with a straightedge and feeler gauges. The gauges will not pass under the centre of the straightedge, but will pass at both ends. What does this indicate?

  1. The surface is flat but the straightedge is worn
  2. The surface is convex, bowing up in the middle
  3. The surface is concave, dipping in the middle Correct answer.
  4. The straightedge is too short for the surface

Explanation

If light or a feeler gauge passes at the ends but not at the centre, the straightedge is touching the high middle and the surface dips away at each end, which is concave. A convex surface would show the opposite pattern, with the gap in the middle. Length and wear would not produce this symmetric end-gap pattern.

Question 47Hand Tools and Bench Skills

Why is a centre punch usually struck with a light hammer blow first, followed by a heavier blow?

  1. The light blow locates the mark accurately before the heavy blow drives it deep Correct answer.
  2. The heavy blow must be delivered first to avoid bending the punch
  3. The first blow tempers the punch tip for the second
  4. Two blows are needed because the punch is too short for a single strike

Explanation

A light initial blow sets a small mark that can be inspected and corrected if it has drifted from the scribed intersection; the heavier blow then deepens it. Reversing the order would drive an inaccurate mark too deep to correct. Punch temper and length are unaffected by the two-stage technique.

Question 48Hand Tools and Bench Skills

A hacksaw is being used to cut a thin-walled tube held in a vice. Which technique gives the cleanest cut?

  1. Use a fine-tooth blade, cut with light pressure and rotate the tube as the cut progresses Correct answer.
  2. Cut straight through with maximum speed to avoid work-hardening
  3. Cut only with the tip of the blade to concentrate force
  4. Use a coarse blade and heavy pressure to finish quickly

Explanation

Thin walls need a fine-tooth blade so several teeth are in contact and do not snag, light pressure to avoid crushing, and rotation to keep the cut progressing around the circumference. Coarse teeth catch on thin walls, and heavy pressure or high speed distorts the tube and dulls the blade.

Question 49Hand Tools and Bench Skills

Which bench operation is correctly described as 'draw filing'?

  1. Moving the file sideways across the work with the blade held at right angles to its length Correct answer.
  2. Filing only in the direction of the layout line
  3. Pulling the file backwards over the work with no pressure
  4. Pushing the file along its length with both hands in the normal forward stroke

Explanation

Draw filing holds the file across the work, at right angles to its length, and draws it sideways along the surface; the fine cutting action removes file marks and produces a flat, smooth finish. Normal filing is a forward push, and pulling without pressure does not cut. Layout direction does not define the technique.

Question 50Hand Tools and Bench Skills

A hole is to be drilled and then hand-reamed to a precise size. What is the correct relationship between the drill and the reamer?

  1. The drill should be the same size as the reamer so the reamer only polishes
  2. The drill should be slightly larger than the reamer to leave clearance
  3. The drill size is irrelevant because the reamer cuts to size regardless
  4. The drill should be slightly smaller than the reamer so the reamer removes a small amount of metal Correct answer.

Explanation

Reamers remove only a small allowance, typically a few hundredths of a millimetre, so the drilled hole must be slightly undersize. An oversize drill leaves too little or no material for the reamer to cut, and an equal-size drill means the reamer cannot correct the hole. The reamer cannot remove a large stock allowance.