Hand Tools
Questions here ask you to choose the correct tool, know its angles and parts, and describe proper care.
Marking tools
Scriber with a hardened point, surface plate, V-block for round work, angle plate, try square, dividers, and punches. A centre punch has a 90 degree point and is used to locate a drill; a dot punch has a 60 degree point and marks layout lines.
Cutting tools
- Hacksaw: 250 or 300 mm blade. Use 18 teeth per inch for thick solid sections, 24 for general work, and 32 for thin tube and sheet. Fit the blade with teeth pointing forward so it cuts on the forward stroke, and tension it firmly. Keep at least two teeth in contact with the work.
- Chisels: flat, cross-cut, diamond and half-round. The cutting angle is about 60 degrees for general work and steeper for hard metal. Grind off a mushroomed head immediately.
- Files: length in millimetres; grades run rough, bastard, second cut and smooth. Single cut for finishing and sharpening, double cut for fast removal. Always fit a handle, clean pins with a file card, and never use a file as a lever or hammer.
Striking and holding
Ball peen hammer for general work and riveting with the peen; soft-faced mallet for assembled or finished parts; bench vice with soft jaws to protect finished surfaces.
Worked example
You must saw a 1 mm sheet. Choose a 32 teeth per inch blade, because fine teeth keep several teeth in contact and cut cleanly. An 18 teeth per inch blade snags, breaks teeth and tears the sheet. Fit teeth forward, use light pressure and short strokes, and for a curved cut use sheet-metal snips instead.
Traps that cost marks
- Blade fitted with teeth backwards.
- Using a file without a handle.
- Leaving a mushroomed chisel head in use.
- Choosing too coarse a blade for thin material.