Use and Maintenance of Hand Tools, Power Tools, and Shop Equipment
What this domain tests
This domain tests correct tool selection, safe use, care, and calibration. Questions often involve torque wrenches, micrometers, vernier calipers, feeler gauges, hydraulic presses, tire changers, and wheel balancers.
Core rules and concepts
- Use a torque wrench to tighten, not to loosen. Set it to the specified value, hold the handle at the grip, and return it to the lowest setting after use.
- Check precision tools before use: close a micrometer and confirm the zero; check a vernier caliper against its zero; keep measuring faces clean.
- A feeler gauge should drag slightly when the clearance is correct; do not force a thick leaf into a narrow gap.
- Inspect power tools for damaged cords, guards, and switches. Secure the work, keep hands away from the bit or blade, and never wear loose clothing near rotating parts.
- Use a hydraulic press with correct support plates and eye protection. Cage the tire during inflation and follow the wheel balancer's calibration procedure.
Worked example
A metric micrometer shows 5.5 mm on the sleeve and 28 on the thimble. Each thimble division is 0.01 mm, so the reading is 5.5 mm + (28 × 0.01 mm) = 5.78 mm. If the specification is 5.75–5.80 mm, the part is within tolerance. The reasoning depends on reading the sleeve and thimble separately before adding.
Traps that cost marks
Using a pipe as a cheater bar; using a click-type torque wrench to break loose a bolt; reading the vernier scale from the wrong zero; using a damaged or uncalibrated instrument; and assuming an extension changes torque when it is inline with the fastener.
Key points
- Torque wrenches tighten; they do not loosen.
- Zero-check micrometers and calipers before measuring.
- Inspect power tools for guards and cord damage.
- Support press work and cage tires during inflation.
- Calibrate or tag out suspect instruments.