Course outline
Module 1
Module 1: Safety and Workshop Setup
Safety and Workshop Setup
Knowledge check
Q1. What is the most important piece of personal protective equipment to wear when grinding or cutting metal?
- A. Cotton gloves
- B. Safety glasses or a face shield
- C. A cap
- D. Ear plugs only
Q2. Why should loose clothing, jewelry, and long hair be secured before operating a lathe or drill press?
- A. They reduce the weight of the machine
- B. They can get caught in rotating parts and cause serious injury
- C. They help keep the workpiece cool
- D. They are required only for indoor workshops
Q3. What should you do with metal chips and swarf produced during machining?
- A. Blow them away with compressed air toward others
- B. Sweep or brush them away with a brush or tool, never with bare hands
- C. Leave them on the floor so they can be recycled later
- D. Wet them with water and throw them in regular trash
Q4. Which practice best describes good workshop housekeeping for metalworking?
- A. Keeping tools scattered across the floor for quick access
- B. Keeping walkways clear, tools stored properly, and floors free of oil and debris
- C. Leaving cutting fluid puddles so the floor stays slippery and cool
- D. Storing flammable liquids next to the welding station
Q5. What is the correct first step before performing maintenance or changing a blade on a power tool?
- A. Turn the tool on briefly to check it
- B. Disconnect the power source or lock out the machine
- C. Wear heavier gloves and continue working
- D. Ask a coworker to hold the switch while you work
Module 2
Module 2: Metal Types and Properties
Metal Types and Properties
Knowledge check
Q1. Which metal is most commonly used as the base material for making steel?
- A. Aluminum
- B. Iron ✓
- C. Copper
- D. Zinc
Why: Steel is an alloy primarily made of iron with a small amount of carbon, so iron is the essential base metal for steel.
Q2. Which property describes a metal's ability to be hammered or rolled into thin sheets without breaking?
- A. Ductility
- B. Malleability ✓
- C. Hardness
- D. Conductivity
Why: Malleability is the ability of a metal to deform under compressive stress, such as hammering or rolling, into thin sheets.
Q3. Which metal is known for being lightweight and highly resistant to corrosion, making it popular for aircraft and beverage cans?
- A. Lead
- B. Aluminum ✓
- C. Nickel
- D. Tin
Why: Aluminum has a low density and forms a protective oxide layer, which makes it lightweight and corrosion resistant, ideal for aircraft and cans.
Q4. What is an alloy?
- A. A metal that has never been heated
- B. A pure metal found in its natural state
- C. A mixture of two or more metals, or a metal combined with other elements ✓
- D. A metal that cannot conduct electricity
Why: An alloy is a mixture created by combining a metal with other metals or elements to improve properties such as strength or corrosion resistance.
Q5. Which property refers to a metal's ability to be drawn into a wire?
- A. Malleability
- B. Ductility ✓
- C. Brittleness
- D. Density
Why: Ductility is the ability of a metal to be stretched or drawn into a thin wire without breaking.
Module 3
Module 3: Measuring and Marking
Measuring and Marking
Knowledge check
Q1. Which measuring tool is best suited for checking the outside diameter of a round bar to the nearest thousandth of an inch?
- A. Steel rule
- B. Outside micrometer ✓
- C. Tape measure
- D. Combination square
Why: An outside micrometer provides precision readings to 0.001 inch (or 0.01 mm), making it ideal for measuring the outside diameter of round stock. A steel rule typically reads only to about 1/64 inch, and a tape measure is even less precise.
Q2. What is the purpose of layout fluid (such as blue marking dye) applied to a metal surface before scribing?
- A. It prevents the metal from rusting during storage
- B. It makes the scribed lines easier to see and more precise ✓
- C. It lubricates the scriber so it glides smoothly
- D. It hardens the surface for better drilling
Why: Layout fluid provides a contrasting coating that makes scribed lines highly visible and crisp, so the scribe cuts clean lines that stand out against the coated surface.
Q3. Which tool is used to mark a line parallel to a straight edge at a set distance from it?
- A. Center punch
- B. Odd-leg caliper ✓
- C. Dividers
- D. Try square
Why: An odd-leg caliper has one leg bent inward and rides along the edge of the workpiece, allowing you to scribe a line parallel to that edge at a consistent offset distance.
Q4. Why is a center punch used before drilling a hole?
- A. To measure the depth of the hole
- B. To create a small indentation that guides the drill bit and prevents wandering ✓
- C. To remove burrs from the hole edge
- D. To mark the hole diameter on the surface
Why: A center punch creates a small dimple at the intended hole center. This recess seats the drill tip so it does not skate or wander across the surface when drilling starts.
Q5. When reading a steel rule, what is the smallest graduation typically found on a standard machinist's rule in inches?
- A. 1/4 inch
- B. 1/8 inch
- C. 1/16 inch
- D. 1/64 inch ✓
Why: Most standard steel rules graduate down to 1/64 inch, which is the finest division commonly found on a general-purpose steel rule. Finer measurements require calipers or micrometers.
Module 4
Module 4: Cutting Techniques
Cutting Techniques
Knowledge check
Q1. Which tool is most commonly used to make straight cuts in sheet metal by hand?
- A. Hacksaw
- B. Tin snips ✓
- C. Cold chisel
- D. Bolt cutters
Why: Tin snips are designed specifically for cutting thin sheet metal cleanly and with control. A hacksaw is better suited to bar stock and tubing, cold chisels are used for cutting or splitting heavier material, and bolt cutters are meant for wire, rods, and bolts rather than flat sheet.
Q2. What is the main purpose of using cutting fluid when machining metal?
- A. To make the metal harder
- B. To remove rust from the workpiece
- C. To reduce friction and heat at the cutting edge ✓
- D. To prevent the metal from bending
Why: Cutting fluid lubricates the contact between the tool and the workpiece while also carrying heat away from the cutting zone. This reduces tool wear, improves surface finish, and helps prevent the workpiece from overheating.
Q3. When using a hacksaw, which direction should the cutting pressure be applied?
- A. On the return stroke
- B. On the forward (push) stroke ✓
- C. Equally on both strokes
- D. Only at the start of the cut
Why: Hacksaw blades cut on the forward stroke, so pressure should be applied only as you push forward. Applying pressure on the return stroke dulls the teeth quickly and can cause the blade to break or skip.
Q4. Why is it important to deburr the edges of metal after cutting?
- A. To change the color of the metal
- B. To increase the weight of the part
- C. To remove sharp burrs that can cause injury and interfere with fit ✓
- D. To make the metal conduct electricity better
Why: Cutting leaves sharp raised edges called burrs. Removing them with a file or deburring tool prevents cuts to the hands, ensures parts fit together properly, and avoids damage to mating surfaces.
Q5. What does the number of teeth per inch (TPI) on a hacksaw blade indicate?
- A. The thickness of the blade
- B. The hardness of the blade
- C. The length of the blade
- D. The fineness of the cut and suitability for different metal thicknesses ✓
Why: TPI describes how many teeth fit in one inch of blade. Higher TPI blades (such as 24 or 32) produce finer cuts and suit thin metal, while lower TPI blades (such as 14) clear chips faster and suit thicker stock.
Module 5
Module 5: Shaping and Bending
Shaping and Bending
Knowledge check
Q1. Which property of a metal most directly allows it to be bent or shaped without cracking?
- A. Hardness
- B. Ductility ✓
- C. Brittleness
- D. Density
Why: Ductility is the ability of a metal to deform plastically under tensile or bending stress without fracturing. Hardness resists deformation, brittleness causes cracking, and density has no direct bearing on formability.
Q2. What is springback in sheet metal bending?
- A. The metal cracking at the bend line
- B. The tendency of the metal to partially return toward its original shape after the bending force is removed ✓
- C. The metal heating up during bending
- D. The bend line moving toward the edge of the sheet
Why: Springback is the elastic recovery of the material after forming. Because part of the deformation is elastic, the bend angle opens slightly once the force is released, so bends are often overbent to compensate.
Q3. What is the purpose of a bend allowance in sheet metal fabrication?
- A. To add extra thickness to the sheet
- B. To calculate the length of material needed through the bend arc so the finished part has the correct dimensions ✓
- C. To set the speed of the press brake
- D. To measure the hardness of the metal after bending
Why: Bend allowance accounts for the arc length of the material in the bend region, which is longer than the straight-line dimensions suggest. Using it ensures the flat blank is cut to the correct size to produce the intended finished part dimensions.
Q4. Why is the bend radius typically kept at or above a minimum value relative to material thickness?
- A. Smaller radii make the metal heavier
- B. Tight bends on the outside of the curve can stretch the surface beyond its limit and cause cracking ✓
- C. Larger radii increase the material's hardness
- D. Minimum radii are required by electrical codes
Why: On the outer surface of a bend the material is stretched in tension. If the radius is too tight relative to thickness, the outer fibers exceed their ductility and crack. Most materials have a recommended minimum bend radius based on their thickness and temper.
Q5. Before bending a metal bar by hand or with a vise, what is a common practice to reduce the chance of cracking when working with harder or thicker stock?
- A. Quench the metal in cold water
- B. Heat the metal to an appropriate temperature for the material ✓
- C. Coat the metal with oil and bend it immediately
- D. Strike the bend point repeatedly with a hammer at room temperature
Why: Heating increases the ductility of many metals, allowing them to bend with less risk of cracking. Quenching or excessive hammering at room temperature tends to harden or work-harden the metal and increases the chance of fracture.
Module 6
Module 6: Drilling and Fastening
Drilling and Fastening
Knowledge check
Q1. Which drill bit material is most commonly used for general-purpose drilling in mild steel and is inexpensive?
- A. Carbide-tipped
- B. High-speed steel (HSS) ✓
- C. Cobalt
- D. Diamond-coated
Why: High-speed steel (HSS) bits hold a sharp edge at higher temperatures than carbon steel and are affordable, making them the standard choice for general metalworking. Carbide and diamond bits are harder but more expensive and brittle, and cobalt is reserved for tougher alloys.
Q2. What is the recommended approach when drilling a hole in sheet metal to prevent the bit from grabbing and spinning the workpiece?
- A. Drill at the highest speed possible
- B. Apply heavy pressure from the start
- C. Clamp the workpiece securely to a solid surface ✓
- D. Hold the metal in your hand while drilling
Why: Clamping the workpiece to a stable surface such as a drill press table or workbench prevents it from spinning when the bit catches, which can cause injury and ruin the part. Holding the metal by hand is dangerous and should be avoided.
Q3. Why should you use a center punch before drilling a hole in metal?
- A. To cool the metal before drilling
- B. To remove burrs from the surface
- C. To create a small dimple that guides the drill bit and prevents wandering ✓
- D. To measure the hole depth
Why: A center punch creates a small indentation at the desired hole location, giving the drill bit tip a starting point so it does not slide across the smooth surface. This improves accuracy.
Q4. What is the purpose of cutting fluid or lubricant when drilling metal?
- A. To make the metal softer
- B. To reduce friction and heat, extending bit life and improving the cut ✓
- C. To prevent rust on the workpiece only
- D. To increase the drill's rotational speed
Why: Cutting fluid reduces friction and heat at the cutting edge, which keeps the bit sharp longer and produces a cleaner hole. Using it is especially important when drilling steel and other tough metals.
Q5. Which fastener is designed to be installed in a pre-drilled hole and then tightened by turning a nut or bolt head against it?
- A. Rivet
- B. Self-tapping screw
- C. Machine bolt with nut ✓
- D. Pop rivet
Why: A machine bolt paired with a nut passes through a pre-drilled clearance hole and is tightened by turning the nut or head, allowing the joint to be disassembled later. Rivets and pop rivets are permanent, and self-tapping screws cut their own threads rather than using a nut.
Module 7
Module 7: Finishing and Surface Treatment
Finishing and Surface Treatment
Knowledge check
Q1. What is the main purpose of sanding metal before applying a finish?
- A. To change the metal's chemical composition
- B. To remove rust, scale, and imperfections so the finish adheres well ✓
- C. To harden the surface permanently
- D. To increase the metal's electrical conductivity
Why: Sanding removes rust, mill scale, and surface imperfections and creates a clean, slightly roughened profile that helps paint, primer, or other finishes bond properly.
Q2. Which grit range is typically used for final sanding of metal before painting?
- A. Coarse grit, around 24 to 36
- B. Medium grit, around 80 to 120
- C. Fine grit, around 180 to 220 ✓
- D. Extra-coarse grit, below 16
Why: Fine grits around 180 to 220 leave a smooth surface with light scratches that help paint adhere without showing deep sanding marks, while coarse grits are used for heavy material removal.
Q3. What does the process of passivation do to stainless steel?
- A. It adds a colored coating to the surface
- B. It removes free iron contamination and enhances the natural protective oxide layer ✓
- C. It melts the surface to create a smooth glaze
- D. It deposits a layer of zinc onto the steel
Why: Passivation uses a mild acid treatment to remove embedded iron particles from the surface, which allows the chromium-rich passive oxide layer to form more fully and improves corrosion resistance.
Q4. What is the primary purpose of applying a primer before a topcoat of paint on metal?
- A. To make the paint dry faster
- B. To improve adhesion and provide corrosion protection ✓
- C. To add shine to the final finish
- D. To remove the need for surface cleaning
Why: Primers bond well to bare metal, improve topcoat adhesion, and often contain corrosion-inhibiting compounds that protect the metal underneath.
Q5. Which finish involves coating steel with molten zinc to protect it from rust?
- A. Anodizing
- B. Powder coating
- C. Hot-dip galvanizing ✓
- D. Bluing
Why: Hot-dip galvanizing immerses steel in molten zinc, creating a metallurgically bonded zinc coating that sacrificially protects the steel from corrosion.