Supplied B1 Module 07A textbook: PDF pages 45–120.
Hand-tool selection
Choose a screwdriver that matches both the recess type and size. Phillips and Reed and Prince profiles are different and should not be substituted. A ring spanner or correctly fitted socket supports more of a fastener than an open-ended spanner. Use an open-ended tool where access demands it, keeping the jaw properly engaged. Pliers should not replace a spanner on a finished nut. Use the specified soft-faced hammer and suitable drift for a task that would be damaged by steel impact.
Why must a screwdriver match the recess type? A mismatched profile can slip and damage the screw.
Cutting, filing and drilling
Match saw blades, files and drill geometry to the material and required finish. A file cuts mainly on its forward stroke; fit a handle to its tang. Secure the work before drilling and keep hands away from rotating tools. Remove the chuck key before running a drill. Use correct speed, feed and lubricant, and deburr the hole without enlarging it beyond limits. Reaming finishes an already prepared hole; it is not a substitute for removing a large amount of stock.
What is a reamer normally used for? Finishing a prepared hole accurately.
Torque and extensions
Torque is force multiplied by perpendicular distance from the rotational axis. Use a suitable calibrated torque wrench, the specified units and the correct lubrication condition. Pull smoothly at the designated handle location; stop when the wrench indicates the setting. An in-line extension that increases effective length generally needs a setting correction. For a straight extension, setting equals required torque times L divided by L plus A, where L and A use the same units. A ninety-degree arrangement usually avoids the simple in-line length increase, but use the tool procedure.
What does an in-line crowfoot extension generally require? A torque setting correction for effective length.
Micrometers and vernier instruments
Clean the faces and workpiece, check zero and use the correct instrument range. A micrometer's spindle screw produces a precise movement; the ratchet or friction device controls measuring force. Read the sleeve and thimble together, including a vernier when provided. A vernier caliper combines a main scale with a subdivided sliding scale and can measure external, internal and depth dimensions. Resolution is the smallest displayed increment; it does not by itself establish accuracy. Align the instrument to the dimension and avoid excessive force.
What is the purpose of a micrometer ratchet? Apply consistent measuring force.
Comparative and contact gauges
A dial indicator measures small displacement relative to a reference and is useful for runout and alignment. A feeler gauge measures a gap with a suitable blade or combination, without forcing the parts apart. Bore gauges compare internal size and need setting against an appropriate reference. Gauge blocks provide precise reference lengths when clean, handled correctly and used under controlled conditions. A go/no-go gauge checks whether size lies within limits; it does not display the actual dimension. Select the method based on the specified feature, not convenience alone.
What does a go/no-go gauge establish? Whether the checked feature meets specified size limits.
Angles, surface condition and measurement errors
Squares, protractors and height gauges check geometry with a suitable reference surface. Parallax affects readings when the eye is not normal to a scale. Dirt, burrs, temperature differences and misalignment can produce readings that look repeatable but are wrong. Allow precision parts and instruments to stabilise where required. A surface plate is a measurement reference, not a general workbench. Take measurements at enough positions to reveal taper or ovality; one diameter reading cannot establish a perfectly cylindrical shaft.
How is shaft ovality best detected? Measure diameters at different angular positions.
Lubrication equipment
Use the specified lubricant, quantity and application method. Clean the lubrication point before connecting a grease gun so dirt is not forced inside. Keep dispensers clearly identified and prevent mixing incompatible greases or oils. Excess grease can overheat a bearing, damage seals or contaminate brakes and surrounding equipment. Pressure lubricators, oil cans and grease guns perform different jobs. A blocked point or unexpectedly high resistance requires investigation rather than uncontrolled extra pressure. Record servicing when the task requires it.
Why is a lubrication fitting cleaned before servicing? Prevent contamination entering with the lubricant.
Electrical general test equipment
Connect a voltmeter in parallel with the points of interest. An ammeter measures current in series, with the correct range and fused input; placing it across a supply can create a short circuit. Resistance and continuity measurements require the circuit to be isolated from power and sensitive equipment as the procedure specifies. Confirm lead placement and function selection before connecting. High-energy systems require appropriately rated instruments. An insulation tester applies a test voltage and must not be connected indiscriminately to electronic equipment.
How is a voltmeter normally connected? In parallel across the points being measured.
Apply the knowledge
Work through these examples before starting the quiz. Explain why the other choices would not meet the requirement.
An in-line adapter adds 50 mm to a 250 mm wrench. Required torque is 60 N·m. What setting follows the simple extension formula?
50 N·m — 60 × 250 / (250 + 50) = 50 N·m; the extension increases the lever arm.
A micrometer reads 12.5 mm on the sleeve and 0.23 mm on the thimble. What is the reading?
12.73 mm — Add the sleeve and thimble readings using the instrument's actual graduations.
A meter is set to current and connected across a battery. What is the principal risk?
A low-resistance short through the meter — Current inputs have low resistance and are not used as voltage inputs.
A bore gives different diameters in two perpendicular directions. What does this indicate?
Ovality — Different angular diameters indicate out-of-round geometry.