Chapter 3. Tools, Equipment and Measurement
Hand tools: hammers, screwdrivers, spanners and wrenches, pliers, chisels, files, hacksaws, hand saws, squares and levels. Use the right tool for the job, keep it clean and sharp, and replace damaged tools [8].
Power tools: drills, angle grinders, circular saws, jigsaws, sanders and impact drivers. Check guards and cords before use, secure the workpiece, wear PPE, and disconnect from power before changing accessories.
Measuring tools
| Instrument | Use | Typical resolution |
| Steel rule / tape measure | General length | 1 mm |
| Try square, combination square | Checking right angles | – |
| Vernier caliper | Inside, outside, depth measurement | 0.02 mm or 0.05 mm |
| Micrometer | Precise outside dimensions | 0.01 mm |
| Spirit level | Horizontal and vertical checking | – |
| Multimeter | Voltage, current, resistance | Varies |
Accuracy, tolerance and fit. No part is made perfectly. A tolerance is the allowable variation in a dimension (for example, 25.00 mm ± 0.05 mm). Parts that must fit together are specified with limits and fits [8][9].
Good measuring practice: “measure twice, cut once,” read at eye level, check zero error, keep instruments clean, handle precision tools carefully and use the right units.
Marking out. Use a scriber or sharp pencil, a rule and square, and a centre punch to mark hole positions.
Fasteners. Screws, bolts, nuts, washers, rivets and nails. Threads are specified by diameter and pitch; use the right driver or spanner to avoid damaging heads.
Review: Convert 2.5 m to millimetres. (Answer: 2,500 mm.)