Workshop Tools, Equipment and Measuring Instruments
Domain 2: Workshop Tools, Equipment and Measuring Instruments
This domain tests correct selection, safe use, care and interpretation of hand tools, power tools, lifting equipment and precision measuring instruments. Accuracy depends as much on technique as on the tool.
Core rules
- Match the tool to the fastener: six-point sockets for damaged nuts, flare-nut wrenches for brake lines, torque wrench for critical fasteners.
- Check calibration and zero before measuring. A micrometer should read zero with the anvils closed; a vernier should close cleanly.
- Read at eye level to avoid parallax error. Clean measuring faces and workpiece before use.
- Metric precision: vernier caliper typically 0.02 mm; outside micrometer 0.01 mm; dial gauge 0.01 mm or 0.001 mm.
- A torque wrench is a measuring instrument. Set it to the specified value, apply smooth force, and never use it to loosen or as a breaker bar.
- Store instruments in cases, away from moisture and impact. Do not mix imperial and metric without conversion.
- Inspect power tools for damaged cords, guards and switches; use RCD protection and the correct disc for the speed.
Worked example
A 0-25 mm micrometer has a sleeve reading of 7.5 mm and a thimble reading of 22 divisions. Each thimble division is 0.01 mm, so the thimble contributes 0.22 mm. The reading is 7.5 + 0.22 = 7.72 mm. If the zero check shows 0.02 mm error, subtract or record the correction before judging wear limits.
Traps
- Using an impact wrench on a torque wrench.
- Reading the wrong vernier scale or forgetting the zero error.
- Measuring a hot engine part; thermal expansion changes the result.
- Using a damaged or worn socket, which rounds fasteners.
- Assuming a calibrated tool stays calibrated after a drop.