Tools and Maintenance
This section covers Tools and Maintenance: selection and care of hand tools, fasteners, bearings, lubrication and maintenance strategies. The exam tests safe tool use, correct fitting and planned maintenance.
Core rules
- Use the correct size: a spanner must fit the nut flats fully; an adjustable wrench is a compromise and can round nuts. Pull a spanner toward you where possible; do not use a cheater bar.
- A screwdriver must match the slot or recess. Do not use a screwdriver as a chisel or pry bar. Keep hacksaw blades tensioned and file handles secure.
- Maintenance types: breakdown (after failure), preventive (scheduled), predictive (condition-based), and corrective (repair). Vibration, temperature and oil analysis support predictive maintenance.
- Lubrication reduces friction and wear but over-greasing can raise temperature and damage seals. Clean the grease nipple before greasing.
- Bearings need correct fit, alignment and clearance. A shaft 25.00 mm and bore 25.03 mm give 0.03 mm clearance.
Worked example
A motor bearing vibrates at 7 mm/s and rises from 2 mm/s over a month. The trend, not one reading, indicates a developing fault. Check alignment, lubrication and bearing condition, then plan a corrective shutdown before failure. This is predictive maintenance: condition data triggers action.
Traps
Do not hammer a bearing on its balls; press on the inner ring for a shaft fit. Do not mix incompatible greases. Do not judge a bearing only by sound when a vibration trend is available.