Hand Tools
This section covers Hand Tools. The exam tests identification, correct use and safe handling of bench and fitting-shop tools such as hammers, chisels, files, hacksaws, taps, dies, spanners, screwdrivers and punches.
Core concepts
- A bench vice holds work; use soft jaws for finished surfaces and do not over-tighten thin tubes.
- A ball-peen hammer is for metalwork; the flat face strikes and the ball face shapes or rivets. The head must be wedged tightly and the handle free from cracks.
- A cold chisel cuts by shearing; the cutting angle depends on material. A mushroomed head must be ground off because it can spall.
- Files cut on the forward stroke. Use a handle; never use a file as a pry bar. Bastard cut removes metal quickly; smooth cut gives a finish. Draw filing improves flatness.
- A hacksaw blade has teeth pointing forward, away from the handle, with correct tension. Coarse pitch, about 18 TPI, suits thick soft sections; fine pitch, about 24–32 TPI, suits thin tube and sheet.
- Taps cut internal threads; dies cut external threads. Use the correct drill size and lubricant.
Worked example
You must cut a 1.5 mm aluminium sheet and a 25 mm mild-steel bar. The thin sheet needs a fine 32 TPI blade so at least two teeth stay in contact with the thin section; a coarse blade can snag and tear it. The thick bar needs an 18 TPI blade to clear chips. Fit both blades with teeth pointing forward and tighten them; the reasoning is chip clearance versus tooth engagement.
Traps that cost marks
A hacksaw blade fitted backwards is a common error. Do not use a spanner as a hammer or a screwdriver as a chisel. Do not continue with a cracked handle or mushroomed chisel head.