CSEC Industrial Tech Exam Prep

Cheatsheet Content

### Heat Treatment Methods - **Purpose:** To alter the physical and sometimes chemical properties of a material. - **Common Methods:** - **Annealing:** Heating a material above its recrystallization temperature, holding it at that temperature for a sufficient time, and then slowly cooling it. - *Purpose:* To increase ductility, reduce hardness, relieve internal stresses, and improve machinability. - **Normalizing:** Heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to room temperature. - *Purpose:* To refine grain structure, improve uniformity, and reduce internal stresses. - **Hardening:** Heating steel to a high temperature and then rapidly cooling it (quenching) in water, oil, or air. - *Purpose:* To increase hardness and strength. Often followed by tempering. - **Tempering:** Reheating hardened steel to a temperature below its critical point, followed by cooling. - *Purpose:* To reduce brittleness and improve toughness after hardening, while retaining some hardness. - **Case Hardening:** Creating a hard surface layer (case) on a low-carbon steel component while retaining a tough, ductile core. - *Methods:* Carburizing, Nitriding, Cyaniding, Induction Hardening. ### Cutting Tools and Tool Maintenance - **Types of Cutting Tools:** - **Single-point:** Lathe tools, shaper tools. - **Multi-point:** Drills, milling cutters, reamers, taps. - **Materials:** High-speed steel (HSS), carbide, ceramics, diamond. - **Key Properties:** Hardness, toughness, wear resistance, hot hardness. - **Maintenance:** - **Sharpening:** Maintaining the correct cutting angles and edge sharpness. - **Cleaning:** Removing swarf and debris. - **Storage:** Protecting tools from damage and corrosion. - **Inspection:** Checking for wear, cracks, or damage. ### Reading and Interpreting Engineering Drawings - **Orthographic Projections:** - **Views:** Front, top, side (left or right). - **Purpose:** To show all dimensions and features accurately. - **Lines:** - **Object lines:** Thick, continuous lines representing visible edges. - **Hidden lines:** Dashed lines representing hidden edges. - **Centre lines:** Long-dash, short-dash lines indicating centres of circles, arcs, or symmetry. - **Dimension lines:** Thin lines with arrowheads indicating dimensions. - **Extension lines:** Extend from the object to the dimension line. - **Dimensions:** - **Linear:** Length, width, height. - **Angular:** Angles. - **Radial/Diametral:** Radii and diameters of circles/arcs. - **Symbols:** Surface finish, welding, tolerances. - **Title Block:** Drawing number, title, scale, date, drafter, material. ### Preparing to Produce Technical Drawings - **Standards:** ISO (International Organization for Standardization), ANSI (American National Standards Institute). - **Equipment:** Drawing board, T-square, set squares, compass, protractor, pencils (H, HB, B grades), eraser. - **Layout:** Title block, borders, revision block. - **Scaling:** Reduction scale (e.g., 1:2), enlargement scale (e.g., 2:1), full scale (1:1). - **Lettering:** Neatly and uniformly executed, typically using guide lines. ### Producing Drawings for Graphic Communication - **Freehand Sketching:** Quick, informal drawings to convey ideas. - **Isometric Drawing:** Pictorial drawing showing three dimensions (length, width, height) at equal angles (30° to the horizontal). - **Oblique Drawing:** Pictorial drawing where one face is parallel to the projection plane, and the depth is shown at an angle (e.g., 45°). - **Cavalier:** True depth. - **Cabinet:** Half depth. - **Perspective Drawing:** Creates a realistic 3D effect as seen by the eye, using vanishing points. - One-point, two-point, three-point perspective. ### Producing Pictorial and Orthographic Drawings - **Orthographic Projection:** - **First Angle:** Object is between the observer and the projection planes. Top view below front, left view to the right of front. (Used in Europe/Asia). - **Third Angle:** Projection planes are between the observer and the object. Top view above front, left view to the left of front. (Used in North America). - **Steps for Orthographic:** 1. Select front view. 2. Project lines to create top and side views. 3. Add hidden lines, centre lines. 4. Dimension the views. - **Steps for Pictorial (e.g., Isometric):** 1. Establish isometric axes. 2. Sketch basic box shape. 3. Add details by drawing on isometric planes. 4. Darken visible lines. ### First and Third Angle Projections - **First Angle Projection:** - Symbol: A truncated cone with the smaller end facing the larger end. - The object is in the first quadrant. - View positions: Top view is below the front view. Right side view is to the left of the front view. - **Third Angle Projection:** - Symbol: A truncated cone with the larger end facing the smaller end. - The object is in the third quadrant. - View positions: Top view is above the front view. Right side view is to the right of the front view. - **Key Difference:** The placement of views relative to the front view. ### Centre Lathe - **Purpose:** To rotate a workpiece against a cutting tool to remove material. - **Main Parts:** - **Headstock:** Contains the main spindle and gears for speed changes. - **Tailstock:** Supports the other end of the workpiece, holds drills, reamers. - **Carriage:** Moves along the bed and holds the cutting tool. - *Composed of:* Saddle, cross-slide, compound rest, tool post. - **Bed:** Foundation of the lathe, guides the carriage and tailstock. - **Leadscrew/Feed Rod:** Used for automatic feeding and thread cutting. - **Operations:** Facing, turning (straight, taper), knurling, drilling, boring, threading. - **Safety:** Eye protection, proper work holding, no loose clothing, clear chip removal. ### Performing Sheet Metal Operations - **Tools:** - **Measuring:** Steel rule, vernier caliper, micrometer. - **Marking out:** Scriber, centre punch, dividers, surface gauge. - **Cutting:** Tin snips, hacksaw, guillotine. - **Forming:** Bending brake, mallets, stakes (bevel, half-moon, hatchet). - **Joining:** Rivet gun, soldering iron, welding equipment. - **Operations:** - **Cutting:** Shearing, punching, blanking. - **Bending:** Forming angles and curves. - **Forming:** Shaping with stakes and mallets. - **Joining:** Riveting, soldering, brazing, welding. - **Hemming/Seaming:** Creating edges for stiffness or joining. - **Safety:** Gloves, eye protection, proper handling of sharp edges. ### Measuring and Computing - **Linear Measurement:** - **Steel Rule:** Basic measurement, typically to 0.5mm or 1/64 inch. - **Vernier Caliper:** More precise, to 0.02mm or 0.001 inch. Measures external, internal, depth, and step dimensions. - **Micrometer Screw Gauge:** Most precise, to 0.01mm or 0.0001 inch. Measures external dimensions. - **Angular Measurement:** Protractor, bevel protractor. - **Surface Roughness:** Surface finish comparator. - **Computing:** Basic calculations for dimensions, tolerances, material requirements. - **Tolerances:** Permissible variation in a dimension. - **Unilateral:** Variation in one direction (e.g., 20.00 +0.05/-0.00). - **Bilateral:** Variation in both directions (e.g., 20.00 +/-0.02). ### Operating Pedestal and Radial Arm Drill Presses - **Pedestal Drill Press:** - **Parts:** Base, column, table, drill head (motor, spindle, chuck). - **Operations:** Drilling, reaming, countersinking, counterboring. - **Work Holding:** Vice, clamps, drill jig. - **Radial Arm Drill Press:** - **Features:** Arm can be raised/lowered and rotated, allowing drilling at various positions over a large workpiece. - **Purpose:** For drilling large or heavy workpieces that are difficult to move. - **Drill Bits:** Twist drills (HSS, carbide-tipped). - **Speeds and Feeds:** - **Speed:** RPM, depends on material hardness and drill bit diameter. - **Feed:** Rate at which the drill advances into the material. - **Safety:** Secure workpiece, eye protection, clear chips, correct speed/feed. ### Grinding Operations - **Purpose:** Abrasive machining process using a grinding wheel to remove small amounts of material for precise dimensions and fine surface finishes. - **Types of Grinding Machines:** - **Bench Grinder:** For sharpening tools, deburring. - **Surface Grinder:** Produces flat, smooth surfaces. - **Cylindrical Grinder:** Grinds external cylindrical surfaces. - **Centreless Grinder:** Grinds cylindrical parts without centres. - **Grinding Wheels:** Composed of abrasive grains (aluminum oxide, silicon carbide) and a bonding material. - **Selection:** Grain size, abrasive type, bond type, grade (hardness). - **Safety:** Eye protection (goggles/face shield), guard in place, correct wheel speed, proper dressing of wheel. ### Performing Welding Operations - **Definition:** A fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. - **Types of Welding:** - **Arc Welding:** - **Shielded Metal Arc Welding (SMAW/Stick):** Uses a consumable electrode coated in flux. - **Gas Metal Arc Welding (GMAW/MIG):** Uses a continuous wire electrode and shielding gas. - **Gas Tungsten Arc Welding (GTAW/TIG):** Uses a non-consumable tungsten electrode and shielding gas for high-quality welds. - **Oxy-Acetylene Welding:** Uses a flame from burning oxygen and acetylene gas. - **Spot Welding:** Resistance welding for joining sheet metal. - **Joint Types:** Butt, lap, tee, corner, edge. - **Safety:** Welding helmet (proper shade), gloves, flame-retardant clothing, ventilation, fire extinguisher. ### Milling Machine - **Purpose:** Uses rotating multi-point cutting tools to remove material from a workpiece, producing flat or irregularly shaped surfaces. - **Types of Milling Machines:** - **Vertical Milling Machine (e.g., Turret Mill/Bridgeport):** Spindle is vertical, table moves in X-Y plane, spindle moves vertically (Z-axis). - **Horizontal Milling Machine:** Spindle is horizontal, uses arbor-mounted cutters. - **Parts:** Base, column, knee, saddle, table, spindle, overarm (horizontal), ram (vertical). - **Milling Operations:** - **Face Milling:** Creating flat surfaces. - **Peripheral Milling (Slab Milling):** Cutting along the periphery of the cutter. - **End Milling:** Using an end mill for slots, pockets, contours. - **Slotting, keyway cutting, gear cutting.** - **Work Holding:** Vice, clamps, rotary table, indexing head. - **Safety:** Eye protection, secure workpiece, correct cutter rotation, clear chips, no loose clothing.