Engineering Workshop Practice and Safety
This section covers Engineering Workshop Practice and Safety: how a general-engineering workshop is organised, how common machines and hand tools are used safely, and how hazards are controlled. The exam tests PPE selection, machine guarding, housekeeping, fire safety and safe sequences for lathe, drilling, grinding and welding operations.
Core rules
- Wear PPE matched to the hazard: safety glasses for chipping, a face shield plus goggles for grinding, a welding helmet with the correct shade for arc welding, and leather gloves for hot work. Gloves must not be worn near rotating spindles.
- Keep guards in place. Never remove a bench-grinder guard, and set the tool rest within about 2 mm of the wheel. Check a wheel for cracks by the ring test before mounting.
- Apply lockout/tagout before cleaning, adjusting or repairing machinery. Isolate the supply, lock the switch, retain the key and verify zero energy.
- Control the fire triangle: fuel, oxygen, heat. Use CO2 or dry powder on electrical fires; never water. Keep exits and extinguishers clear.
- Use the correct hand tool: a spanner that fits the nut, a brush-not compressed air-to clear chips, and a bench hook for hacksawing.
Worked example
A 200 mm grinding wheel runs at 3000 rpm. Surface speed is πDN/60 = π × 0.20 × 3000/60 = 31.4 m/s. If the wheel is marked 35 m/s, the speed is acceptable; if marked 30 m/s, it is overspeed and must not be used. The reasoning uses wheel diameter in metres and converts rpm to seconds.
Traps
Depth of cut on a lathe reduces diameter by twice the depth, so a 2 mm depth reduces diameter by 4 mm. Do not use compressed air for cleaning. Do not assume a guard is unnecessary for a “small” job.