Hand Tools, Power Tools and Measuring Instruments
Hand Tools, Power Tools and Measuring Instruments tests correct tool selection, safe use, and accurate measurement. The exam expects you to know which tool suits a pipe, how to read a vernier, and why a power tool needs inspection before use.
Hand tools
- Pipe wrench: size by pipe diameter; jaws face the pipe; pull the handle toward you; never use it as a hammer.
- Basin wrench: reaches tap nuts behind a close-coupled basin.
- Chain vice: holds pipe without crushing; a tube cutter gives a square cut; deburr both ends.
- Plunger and drain auger: clear blockages without damaging the trap.
Measuring
Tape and steel rule for lengths; try square for squareness; spirit level for level; plumb bob for verticality; vernier caliper least count 0.02 mm; micrometer least count 0.01 mm.
Power tools
Hammer drill, core cutter and angle grinder need a visual check, the correct bit, an RCD, goggles and no loose clothing. Clamp the work; do not force a blunt bit.
Worked example
A vernier reads main scale 12 mm and the 6th vernier line coincides. Least count = 0.02 mm. Reading = 12 + (6 × 0.02) = 12.12 mm. Check the zero error first; if the zero is +0.03 mm, subtract it.
Traps
Reading the main scale before the vernier zero, using a pipe wrench on plastic threads, or measuring from a damaged pipe end costs marks. A spirit level checks level, not slope; use a gradient or calculate fall.