Hand Tools
What this domain tests
This domain examines correct selection, inspection and use of spanners, sockets, torque wrenches, screwdrivers, pliers, hacksaws, files, chisels, punches, pullers and circlip pliers. The exam favours questions about tool-to-fastener fit, mechanical advantage and damage caused by abuse.
Core rules
- Ring spanners contact all six flats and resist higher torque than open-ended spanners. Use an open-ended or flare-nut spanner only where access demands it.
- The spanner must fully seat on the fastener. A loose fit rounds hex corners and injures knuckles.
- A torque wrench is a setting instrument, not a breaker bar. Set the scale, pull smoothly and return it to the lowest setting after use.
- Screwdriver tip width and thickness must match the slot; a worn tip cams out and chews the screw head.
- Hacksaw blades are fitted with teeth pointing forward; select tooth pitch for material thickness. Fine pitch suits thin tube, coarse pitch suits thick solid stock.
- Files cut on the forward stroke; lift on return. Never use a file without a handle.
- Cold chisels need a correctly ground cutting angle, usually about 60–70°, and a mushroomed head must be dressed or discarded.
Worked example
A fastener needs 25 N·m and the torque wrench handle is gripped 0.25 m from the socket axis. Required force = torque ÷ lever length = 25 ÷ 0.25 = 100 N. If a 0.5 m cheater bar were used instead, the same 100 N hand force would apply about 50 N·m and could stretch or shear the bolt.
Traps that cost marks
Using an adjustable wrench for high torque; extending a torque wrench with a pipe; pulling a file backwards; using a screwdriver as a chisel; fitting a hacksaw blade with teeth reversed.
Key points
- Ring spanner before open-ended spanner.
- Torque = force × lever length.
- Match screwdriver tip to slot size.
- Hacksaw teeth point forward.
- Dressed chisel heads, never mushroomed ones.