42 Auto & Shop Information (AS) Practice Questions & Answers

1. 1. In a four-stroke gasoline engine, during which stroke are both valves closed while the piston moves upward to squeeze the air-fuel mixture before the spark?

   • A.The intake stroke
   • B.The compression stroke✓ Answer
   • C.The power stroke
   • D.The exhaust stroke

   The four strokes run intake, compression, power, exhaust. On the compression stroke both valves are shut and the rising piston squeezes the mixture into the combustion chamber; the spark fires near the top of this stroke and starts the power stroke. The intake valve is open during intake, and the exhaust valve is open during exhaust.

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2. 2. In engine specifications, what does the term "stroke" describe?

   • A.The ratio of the cylinder's volume with the piston at the bottom versus the top
   • B.The diameter of the cylinder that the piston slides up and down inside
   • C.The distance the piston travels from the top to the bottom of the cylinder✓ Answer
   • D.The total volume that all of the pistons sweep through in one engine cycle

   Stroke is the length of piston travel between top dead center and bottom dead center. The cylinder's diameter is the bore, the total volume swept by all pistons is the displacement, and the ratio of cylinder volume at bottom versus top is the compression ratio; these terms are commonly mixed up.

   Ref QB-235RHFSource: officialasvab.com, ASVAB Subtests - Auto Information; standard engine terminology (bore, stroke, displacement, compression ratio)Report a problem with this question

3. 3. Once a diesel engine is running, how is the fuel in each cylinder ignited?

   • A.Glow plugs stay red-hot the whole time and light each charge of fuel
   • B.A spark plug in each cylinder fires near the top of the compression stroke
   • C.The ignition coil sends a high-voltage pulse through each fuel injector
   • D.Air is compressed until it is hot enough to ignite the fuel as it is injected✓ Answer

   A diesel uses compression ignition: its high compression ratio heats the air so much that fuel sprayed into the cylinder ignites by itself, so it has no spark plugs or ignition coil. Glow plugs only help warm the chamber for cold starts; they do not light every power stroke.

   Ref QB-HJXJXESource: officialasvab.com, ASVAB Subtests - Auto Information; diesel compression-ignition principleReport a problem with this question

4. 4. A car is driven almost only on short, slow trips around town, and its spark plugs keep fouling with carbon deposits. Which spark plug change usually helps most?

   • A.A plug with a much narrower gap, so the spark pushes through the carbon
   • B.A plug with no internal resistor, so a stronger spark burns off the carbon
   • C.A hotter heat-range plug, so the tip stays hot enough to burn off carbon✓ Answer
   • D.A colder heat-range plug, so the tip runs cooler and resists overheating

   Heat range describes how quickly a plug sheds heat. A hotter plug keeps its insulator tip hotter, so carbon from short, low-speed driving burns off instead of building up. Colder plugs suit sustained high-speed, high-load driving, where a hot plug could overheat and cause pre-ignition.

   Ref QB-Z2SDCESource: officialasvab.com, Auto Information sample item concept (spark plug heat range and carbon fouling); spark plug heat-range principleReport a problem with this question

5. 5. In a modern coil-on-plug ignition system with no distributor, what determines when each coil fires?

   • A.Breaker points opened by lobes on a shaft, with a condenser to stop arcing
   • B.A rotor turning inside a distributor cap, driven off the engine's camshaft
   • C.The oxygen sensor, which signals when the mixture is rich enough to burn
   • D.The engine computer, using signals from the crankshaft and camshaft sensors✓ Answer

   In distributorless and coil-on-plug systems, the engine computer reads crankshaft and camshaft position sensors to know where each piston is, then switches the matching coil at the right moment. A distributor rotor and breaker points with a condenser belong to older systems, and the oxygen sensor reports exhaust oxygen for fuel control, not spark timing.

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6. 6. An engine gives off black exhaust smoke, its fuel mileage has dropped sharply, and its spark plugs are coated with dry black soot. What condition is most likely?

   • A.A rich mixture, with too much fuel for the amount of air entering✓ Answer
   • B.Coolant leaking into the cylinders through a failed head gasket
   • C.A lean mixture, with too much air and not enough fuel for that air
   • D.Oil burning in the cylinders because the piston rings are worn out

   Black smoke, dry sooty plugs and poor mileage are the classic signs of a rich mixture: there is more fuel than the air can burn completely (the chemically ideal ratio is about 14.7:1). A lean mixture tends to cause pinging or overheating instead, burning oil gives blue smoke, and coolant gives white smoke.

   Ref QB-Y2E37DSource: officialasvab.com, ASVAB Subtests - Auto Information; air-fuel ratio (stoichiometric about 14.7:1) and exhaust smoke diagnosisReport a problem with this question

7. 7. What supplies the power that spins a turbocharger's compressor?

   • A.A set of gears taken directly off the camshaft timing chain
   • B.Intake vacuum created as the pistons move down on the intake stroke
   • C.Hot exhaust gas flowing through a turbine wheel on a shared shaft✓ Answer
   • D.A belt running from the crankshaft pulley at the front of the engine

   A turbocharger is exhaust-driven: exhaust gas spins a turbine wheel, and a shaft connects it to the compressor wheel that packs more air into the intake. A supercharger is the device driven mechanically by a belt from the crankshaft, which is why the two are often confused.

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8. 8. What is the main job of the catalytic converter in a car's exhaust system?

   • A.Quieting exhaust noise by routing the gas through baffled chambers
   • B.Sending some exhaust back into the intake to lower combustion heat
   • C.Turning CO, HC and NOx into carbon dioxide, water and nitrogen✓ Answer
   • D.Measuring leftover oxygen so the computer can correct the mixture

   The catalytic converter uses catalyst metals to change carbon monoxide, unburned hydrocarbons and nitrogen oxides into carbon dioxide, water and nitrogen. Quieting noise is the muffler's job, measuring leftover oxygen is the oxygen sensor's job, and routing exhaust back into the intake is the EGR valve's job.

   Ref QB-73WDDNSource: officialasvab.com, ASVAB Subtests - Auto Information; exhaust emission controls (catalytic converter, oxygen sensor, EGR, muffler)Report a problem with this question

9. 9. A car keeps needing oil added between changes and puts out bluish-gray exhaust smoke, especially on startup and when accelerating. What is the most likely cause?

   • A.Too much fuel being sprayed in by an injector that is stuck open
   • B.Water vapor condensing in a cold exhaust pipe on chilly mornings
   • C.Oil getting into the cylinders past worn piston rings or valve seals✓ Answer
   • D.Coolant entering the cylinders through a leaking head gasket

   Blue or bluish-gray smoke together with oil consumption means engine oil is burning in the combustion chamber, usually because worn rings or valve stem seals let it past. White, sweet-smelling smoke points to coolant, black smoke to excess fuel, and thin white vapor that clears once warm is only harmless condensation.

   Ref QB-PJQ8TMSource: officialasvab.com, ASVAB Subtests - Auto Information; exhaust smoke color diagnosis (blue = oil, white = coolant, black = rich)Report a problem with this question

10. 10. While driving, the red oil-pressure warning light comes on and stays on. What should the driver do?

    • A.Pull over safely, shut the engine off, and check the oil before going on✓ Answer
    • B.Raise engine speed so the oil pump turns faster and brings pressure back up
    • C.Turn the cabin heater to full hot so it draws extra heat away from the engine
    • D.Keep driving until the next oil change, since the light is a service reminder

    The oil-pressure light means oil is not reaching the bearings under enough pressure, and running the engine that way can destroy it within minutes. The safe response is to stop and shut the engine off, then check the level. Running the heater is a trick for an overheating engine, and revving only adds wear while lubrication is failing. It is a warning, not a maintenance reminder.

    Ref QB-8RJ29MSource: officialasvab.com, ASVAB Subtests - Auto Information; lubrication system (oil pump, oil pressure warning)Report a problem with this question

11. 11. The dipstick shows milky, light-brown oil, and the coolant reservoir keeps dropping even though no leak can be seen under the car. What is the most likely problem?

    • A.Coolant mixing into the oil, often through a failed head gasket✓ Answer
    • B.Fuel washing past the rings because the mixture has been running rich
    • C.An oil of heavier viscosity than the engine maker calls for
    • D.Old oil that has gone far past its change interval and filled with soot

    Milky oil is an emulsion of oil and coolant, and coolant that disappears with no outside leak is going somewhere inside the engine. A failed head gasket (or a cracked head) is the usual path. Old oil turns dark and sludgy rather than milky, and fuel dilution thins the oil without turning it milky.

    Ref QB-R8R7UMSource: officialasvab.com, ASVAB Subtests - Auto Information; lubrication and cooling diagnosis (coolant contamination of oil, head gasket)Report a problem with this question

12. 12. An engine starts to overheat within minutes of a cold start. The coolant is full, but the upper radiator hose stays cool while the temperature gauge climbs. What is the most likely cause?

    • A.A thermostat stuck closed, blocking coolant flow to the radiator✓ Answer
    • B.A heater core clogged with rust and debris behind the dashboard
    • C.A radiator cap holding too much pressure in the cooling system
    • D.A thermostat stuck open, sending too much coolant through the radiator

    The thermostat stays closed until the engine reaches operating temperature and then opens to send hot coolant to the radiator. If it sticks closed, hot coolant never reaches the upper hose or radiator, so the hose stays cool while the engine overheats. A thermostat stuck open does the opposite and makes the engine run cold, and a clogged heater core affects cabin heat, not engine overheating. A cap holding too much pressure would not keep the upper hose cool.

    Ref QB-7R7Q3KSource: officialasvab.com, ASVAB Subtests - Auto Information; cooling system operation (thermostat, radiator)Report a problem with this question

13. 13. Why is a car's cooling system sealed with a pressure-type radiator cap?

    • A.It lets you check the coolant level safely while the engine is hot
    • B.The pressure pushes coolant through the engine without a water pump
    • C.Sealing out cold air keeps the coolant from freezing in winter
    • D.Holding the coolant under pressure raises its boiling point✓ Answer

    Raising the pressure on a liquid raises the temperature at which it boils, so a pressurized system can run hotter without boiling over. The water pump still circulates the coolant, freeze protection comes from the antifreeze in the mix, and a hot pressurized cap must never be opened because scalding coolant can spray out.

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14. 14. With the engine running, the battery warning light comes on and the headlights slowly grow dimmer. Which component is most likely failing?

    • A.The ignition coil, which supplies the voltage for the headlight circuit
    • B.The starter solenoid, which routes charging current back to the battery
    • C.The alternator, which should recharge the battery while the engine runs✓ Answer
    • D.The starter motor, which keeps spinning to power the lights once running

    While the engine runs, the alternator powers the electrical system and recharges the battery. When it fails, everything runs off the battery alone, so the charge warning light comes on and the lights dim as the battery drains. The starter and its solenoid work only while cranking, and the ignition coil feeds the spark plugs, not the headlights.

    Ref QB-AR9QKPSource: officialasvab.com, ASVAB Subtests - Auto Information; charging system (alternator, battery warning light)Report a problem with this question

15. 15. When the key is turned, a rapid clicking comes from under the hood, the engine does not crank, and the dash lights dim. What is the most likely cause?

    • A.A weak battery or corroded terminals that cannot feed the starter✓ Answer
    • B.Fouled spark plugs, so the engine cannot fire to begin turning over
    • C.A clogged fuel filter, starving the engine before it can start to turn
    • D.An empty fuel tank, so the starter will not engage without fuel pressure

    Rapid clicking with no crank means the starter solenoid is trying to engage but the starter is not getting enough current, which points to a weak battery or a poor, corroded connection. Fuel and spark problems cause a crank-no-start: the engine still turns over normally but will not run, because the starter does not depend on fuel or spark.

    Ref QB-T8FV6QSource: officialasvab.com, ASVAB Subtests - Auto Information; starting system diagnosis (no-crank vs crank-no-start)Report a problem with this question

16. 16. When a car turns a corner, the outside drive wheel must roll farther than the inside one. Which component allows the two drive wheels to turn at different speeds?

    • A.The transfer case
    • B.The torque converter
    • C.The differential✓ Answer
    • D.The universal joint

    The differential splits engine power between the left and right drive wheels while letting them turn at different speeds in a turn, which prevents tire scrubbing. The transfer case splits power between front and rear axles on a 4WD vehicle, the torque converter couples the engine to an automatic transmission, and a universal joint lets a driveshaft bend at an angle.

    Ref QB-9RWCENSource: officialasvab.com, ASVAB Subtests - Auto Information; drivetrain components (differential, transfer case, torque converter, U-joint)Report a problem with this question

17. 17. A front-wheel-drive car makes a loud clicking or popping noise that is worst during sharp turns while accelerating. What is the most likely cause?

    • A.A low level of fluid inside the torque converter's housing
    • B.A slipping clutch disc that can no longer grip the flywheel
    • C.A worn universal joint on the driveshaft running to the rear axle
    • D.A worn outer constant-velocity (CV) joint on a front drive axle✓ Answer

    Front-wheel-drive axles use constant-velocity joints so they can deliver power while the wheels steer, and a worn outer CV joint clicks most when it is sharply angled under load. A front-wheel-drive car has no driveshaft to a rear axle, and a slipping clutch or low converter fluid shows up as engine speed rising without matching acceleration, not as a turning noise.

    Ref QB-S84JZNSource: officialasvab.com, ASVAB Subtests - Auto Information; drivetrain (CV joints on FWD axles vs U-joints on RWD driveshafts)Report a problem with this question

18. 18. The brake pedal feels soft and spongy and sinks farther than normal before the brakes grip. What is the most likely cause, and the usual fix?

    • A.Glazed brake rotors; resurface or replace the rotors
    • B.A stretched parking brake cable; adjust the cable tension
    • C.Air in the hydraulic brake lines; bleed the brake system✓ Answer
    • D.Brake pads worn to the wear indicator; replace the pads

    Brake fluid does not compress, but air does, so air trapped in the lines squeezes down when the pedal is pressed and makes the pedal spongy. Bleeding the brakes pushes the air out. Worn pads usually announce themselves by squealing, glazed rotors cause weak or noisy braking, and the parking brake is a separate mechanical cable system.

    Ref QB-CRYCXRSource: officialasvab.com, ASVAB Subtests - Auto Information; hydraulic brake system (spongy pedal, bleeding)Report a problem with this question

19. 19. What is the main purpose of an anti-lock braking system (ABS)?

    • A.To hold the car in place on a hill once the parking brake is released
    • B.To keep the wheels from locking in a hard stop so the driver can still steer✓ Answer
    • C.To apply the brakes on its own when the car gets too close to the car ahead
    • D.To shorten the stopping distance on every road surface, including gravel

    ABS senses when a wheel is about to lock and rapidly releases and reapplies pressure to that brake, so the tires keep rolling and the driver keeps steering control. It does not always shorten stopping distance; on loose gravel or snow it can even lengthen it. Automatic braking for a car ahead and hill holding are separate features.

    Ref QB-V86JHSSource: officialasvab.com, ASVAB Subtests - Auto Information; anti-lock brake system principleReport a problem with this question

20. 20. A tire is worn on both outer edges (shoulders) while the center of the tread still has plenty of depth. What is the most likely cause?

    • A.Worn-out shock absorbers on that axle
    • B.Too much positive camber on that wheel
    • C.Driving with the tire overinflated
    • D.Driving with the tire underinflated✓ Answer

    An underinflated tire sags in the middle, so the load rides on the shoulders and both edges wear first. Overinflation does the reverse and wears the center, excess camber wears only one edge, and worn shock absorbers leave a scalloped or cupped pattern around the tire.

    Ref QB-QDGGGHSource: officialasvab.com, ASVAB Subtests - Auto Information; tire wear pattern diagnosis (inflation, alignment, shocks)Report a problem with this question

21. 21. In wheel alignment, what does the caster angle describe?

    • A.Whether the fronts of the two tires point toward or away from each other
    • B.The forward or backward tilt of the steering axis, viewed from the side✓ Answer
    • C.How much farther the inside wheel steers than the outside one in a turn
    • D.The inward or outward tilt of the top of the tire, viewed from the front

    Caster is the fore-and-aft tilt of the steering axis seen from the side; it gives straight-line stability and helps the steering wheel return to center after a turn. The in-or-out tilt of the tire seen from the front is camber, the toward-or-away pointing of the tires is toe, and the extra steering of the inside wheel is toe-out on turns.

    Ref QB-7WABWGSource: officialasvab.com, ASVAB Subtests - Auto Information; wheel alignment angles (camber, caster, toe)Report a problem with this question

22. 22. A worker needs to tap wooden furniture parts together without denting or marking the surface. Which tool is best for this job?

    • A.A claw hammer
    • B.A rubber mallet✓ Answer
    • C.A small sledgehammer
    • D.A ball-peen hammer

    A mallet has a soft face of rubber, wood or rawhide, so it delivers a blow without marring the work. Steel-faced claw and ball-peen hammers dent wood, and a sledgehammer is meant for heavy driving such as stakes or breaking rock.

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23. 23. Before drilling a hole in a steel plate, a machinist makes a small dent at the exact spot so the drill bit will not wander. Which tool makes this dent?

    • A.A pin punch
    • B.A center punch✓ Answer
    • C.A nail set
    • D.A cold chisel

    A center punch has a hardened conical point that leaves a small dimple, which seats the tip of the drill and keeps it from walking. A nail set sinks nail heads, a pin punch drives out pins, and a cold chisel cuts metal.

    Ref QB-6WXYQFSource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Punches: center punch useReport a problem with this question

24. 24. A carpenter must cut a long board lengthwise, parallel to the wood grain. Which handsaw is designed for this cut?

    • A.A ripsaw✓ Answer
    • B.A hacksaw
    • C.A crosscut saw
    • D.A coping saw

    A ripsaw has chisel-shaped teeth that cut with the grain. A crosscut saw has knife-like teeth for cutting across the grain, a coping saw cuts curves, and a hacksaw cuts metal.

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25. 25. When installing a new blade in a hacksaw frame, which way should the teeth point?

    • A.Toward the handle, so it cuts on the pull stroke
    • B.Either direction, since it cuts on both strokes equally
    • C.Toward the handle, so the blade is under less tension
    • D.Away from the handle, so it cuts on the push stroke✓ Answer

    A hand hacksaw is designed to cut on the forward (push) stroke, so the teeth must point away from the handle; you ease pressure on the return stroke. Teeth pointing toward the handle would cut only on the pull stroke and dull the blade, and tension is set by the frame's wing nut, not by tooth direction.

    Ref QB-5WKNJESource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Hacksaw blade installationReport a problem with this question

26. 26. Which file is best for a smooth finishing pass or for sharpening a tool edge on metal?

    • A.A double-cut file
    • B.A coarse wood rasp
    • C.A single-cut file✓ Answer
    • D.A round rattail file

    A single-cut file has one set of parallel teeth, which removes metal slowly and leaves a smooth surface, so it is used for finishing and sharpening. A double-cut file has crossing rows of teeth for fast, rough removal, a rasp is for wood, and a round file is for enlarging round holes.

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27. 27. Before changing the bit in an electric drill, what should you do first?

    • A.Unplug the cord or remove the battery pack✓ Answer
    • B.Hold the trigger lightly so the chuck stays still
    • C.Switch the trigger off but leave it plugged in
    • D.Run it briefly in reverse to loosen the chuck

    Disconnecting the power source (unplugging the cord or removing the battery) is the only way to make sure the drill cannot start while your hand is at the chuck. A switch can be bumped on, and running or holding the trigger keeps the tool live.

    Ref QB-4W8BDDSource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Power tool safety: disconnect power before changing bits or bladesReport a problem with this question

28. 28. Why should slip-joint pliers not be used to tighten or loosen a hex nut?

    • A.Their jaws grip unevenly and round off the nut's corners✓ Answer
    • B.Their jaws are too soft and will crack under the turning load
    • C.They apply so much force that they strip the bolt's threads
    • D.They cannot open wide enough to fit any standard hex nut

    Pliers are made for gripping and holding; their serrated jaws touch the nut at only a few points and slip, which chews up and rounds off the flats and corners. A wrench that fits the flats spreads the load and turns the nut cleanly.

    Ref QB-KD36TCSource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Pliers: correct use (gripping, not turning nuts)Report a problem with this question

29. 29. A nut is very tight and its corners are starting to wear. Which wrench is least likely to round it off?

    • A.A standard open-end wrench
    • B.A large adjustable wrench
    • C.A serrated-jaw pipe wrench
    • D.A 6-point box-end wrench✓ Answer

    A 6-point box-end wrench surrounds the nut and pushes on all six flats, away from the corners, so it holds a worn or tight nut best. An open-end wrench grips only two flats and can spread, an adjustable wrench's movable jaw can loosen, and a pipe wrench's teeth bite into the nut.

    Ref QB-3WVY7CSource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Wrenches: box-end vs. open-endReport a problem with this question

30. 30. When using an adjustable wrench, which way should you pull it?

    • A.Either way, since both jaws are equally strong
    • B.So the fixed jaw takes the main load✓ Answer
    • C.So the movable jaw takes the main load
    • D.With the adjusting screw on top of the nut

    Position the wrench so the pulling force bears against the fixed jaw, which is part of the solid body. The movable jaw rides on the adjusting screw and is weaker; loading it can spread the jaws, slip, and round off the nut.

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31. 31. A plan says a bolt must be tightened to an exact specified tightness. Which tool lets you do this?

    • A.A speed handle
    • B.A breaker bar
    • C.A box-end wrench
    • D.A torque wrench✓ Answer

    A torque wrench measures and indicates the turning force being applied, so you can stop at the specified value. A breaker bar gives extra leverage to loosen stubborn fasteners, and a speed handle and a box-end wrench give no reading of tightness.

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32. 32. Which power tool is used to cut decorative edges and grooves along a wooden board?

    • A.A jigsaw
    • B.A router✓ Answer
    • C.A belt sander
    • D.A circular saw

    A router spins a shaped bit at high speed to mold edges and cut grooves, dadoes and rabbets. A jigsaw cuts curves, a circular saw makes straight cuts, and a belt sander smooths surfaces.

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33. 33. A flat-head wood screw must sit flush with the surface. Which bit cuts the cone-shaped recess for its head?

    • A.A countersink bit✓ Answer
    • B.A counterbore bit
    • C.A spade bit
    • D.A hole saw

    A countersink bit cuts a cone-shaped recess that matches the tapered underside of a flat-head screw so it sits flush. A counterbore cuts a flat-bottomed, straight-sided recess for round heads or plugs, a spade bit bores flat-bottomed holes, and a hole saw cuts large round openings.

    Ref QB-6UZTQFSource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Drill bits: countersink vs. counterboreReport a problem with this question

34. 34. On a steel rule marked in 1/16-inch divisions, an edge lines up 6 marks past the 2-inch line. What is the measurement?

    • A.2 5/8 in
    • B.2 3/8 in✓ Answer
    • C.2 3/4 in
    • D.2 3/16 in

    Six sixteenths is 6/16, which reduces to 3/8, so the reading is 2 3/8 in. Reading 2 3/4 in comes from treating the marks as eighths (6/8); 2 5/8 in comes from counting the 6 marks back from the 3-inch line; 2 3/16 in comes from halving only the numerator instead of reducing the whole fraction.

    Ref QB-JBSNMBSource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Measuring: reading fractional inch rule graduationsReport a problem with this question

35. 35. Which tool measures a small gap, such as the clearance between two machined parts?

    • A.A feeler gauge✓ Answer
    • B.A thread gauge
    • C.A micrometer
    • D.A depth gauge

    A feeler (thickness) gauge is a set of thin blades of known thickness slipped into a gap until one fits snugly. A micrometer measures the outside size of a part, a thread gauge checks threads per inch, and a depth gauge measures how deep a hole or recess is.

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36. 36. A carpenter needs to copy an existing 52-degree angle from one board onto another. Which tool is made for this?

    • A.A combination square
    • B.A sliding T-bevel✓ Answer
    • C.A try square
    • D.A plumb bob

    A sliding T-bevel has a blade that pivots and locks at any angle, so it can pick up an angle from one piece and transfer it to another. A try square checks only 90 degrees, a combination square handles 90 and 45 degrees, and a plumb bob checks vertical.

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37. 37. Which feature identifies a lag screw?

    • A.A slotted oval head driven with a screwdriver
    • B.A domed head with a square neck beneath it
    • C.A square or hex head turned with a wrench✓ Answer
    • D.A blunt tip and machine threads for a nut

    A lag screw is a heavy wood screw with a square or hex head, so it is driven with a wrench or socket rather than a screwdriver. A slotted oval head belongs to an ordinary wood screw, a domed head with a square neck is a carriage bolt, and machine threads made for a nut describe a bolt.

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38. 38. What is a double-headed (duplex) nail mainly used for?

    • A.Hardwood flooring, where the nail is driven at an angle
    • B.Roofing, where a wide head holds down the shingles
    • C.Finish trim, where the head is set below the surface
    • D.Temporary work, like scaffolds, that will be taken apart✓ Answer

    A double-headed nail is driven to the first head, leaving the second head sticking out so it can be pulled easily; that is why it is used for scaffolding, concrete forms and other temporary work. Finishing nails are set below the surface, roofing nails have wide heads, and flooring nails are driven at an angle.

    Ref QB-GB3Z99Source: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Fasteners: double-headed (duplex) nailsReport a problem with this question

39. 39. Two pieces of sheet metal must be joined, but you can reach only one side of the joint. Which fastener is designed for this?

    • A.A solid rivet
    • B.A blind (pop) rivet✓ Answer
    • C.A machine bolt and nut
    • D.A carriage bolt

    A blind (pop) rivet is inserted and set entirely from one side: a rivet tool pulls the mandrel, which flares the far end of the rivet behind the sheets. A solid rivet must be bucked from the back, and a carriage bolt or machine bolt needs a nut placed on the far side.

    Ref QB-ZT86V9Source: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Fasteners: blind (pop) rivetsReport a problem with this question

40. 40. In nail sizing, what does the number in a size such as 16d indicate?

    • A.The diameter of the shank
    • B.The number of nails per pound
    • C.The width of the nail head
    • D.The length of the nail✓ Answer

    The penny system (written with a d) rates nail length: the higher the penny number, the longer the nail; a 16d nail is about 3 1/2 in long. It does not directly state shank diameter, head width, or how many nails make a pound.

    Ref QB-H9G6FASource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Fasteners: penny (d) nail sizingReport a problem with this question

41. 41. A board sold as a nominal 2x4 has about what actual dressed size?

    • A.1 1/2 x 3 1/2 in✓ Answer
    • B.1 1/2 x 4 in
    • C.1 3/4 x 3 3/4 in
    • D.2 x 4 in

    Nominal sizes are the rough-sawn dimensions; drying and planing remove about 1/2 in from each, so a 2x4 is about 1 1/2 x 3 1/2 in. Choosing 2 x 4 in assumes nominal equals actual, 1 3/4 x 3 3/4 in assumes only 1/4 in is lost, and 1 1/2 x 4 in reduces only the thickness.

    Ref QB-ZRAZU9Source: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Lumber: nominal vs. actual sizeReport a problem with this question

42. 42. Which joining process melts the base metal of both pieces so they fuse together?

    • A.Brazing
    • B.Welding✓ Answer
    • C.Riveting
    • D.Soldering

    Welding melts the edges of the base metals (usually with filler) so they flow together into one piece. Soldering and brazing melt only a filler metal that bonds to the surfaces without melting the base metal, with brazing done at higher temperature, and riveting is a mechanical fastener.

    Ref QB-J9UGMBSource: Official ASVAB subtests (officialasvab.com), Shop Information: knowledge of tools and shop terminology and practices — Joining metals: welding vs. soldering vs. brazingReport a problem with this question

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